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HomeMy WebLinkAboutAPA3499SEDIMENT TRANSPORT CHARACTERISTICS OF SELECTED STREAMS IN THE SUSITNA RIVER BASIN, ALASKA, OCTOBER 1983 TO SEPTEMBER 1984 UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY SEDIMENT TRANSPORT CHARACTERISTICS OF SELECTED STREAMS IN THE SUSITNA RIVER BASIN,ALASKA,OCTOBER 1983 TO SEPTEMBER 1984 by James M.Knott,Stephen W.Lipscomb,and Terry W.Lewis OPEN-FILE REPORT 86-424W Prepared in cooperation with the ALASKA POWER AUTHORITY Anchorage,Alaska 1986 i UNITED STATES DEPARTMENT OF THE INTERIOR DONALD PAUL HODEL,Secretary GEOLOGICAL SURVEY Dallas L.Peck,Director For additional information write to: District Chief U.S.Geological Survey Water Resources Division 4230 University Drive,Suite 201 Anchorage,Alaska 99508-4664 ii Copies of this report can be purchased from: U.S.Geological Survey Books and Open-File Reports Section Federal Center,Bldg.41 Box 25425 Denver,Colorado 80225 Telephone:(303)236-7476 CONTENTS Page •• ••• •••• •••• ••••• • ••• •••• •••• ••• •• • ••• ••• •• ••• • •••• •• • •••••••1 1 4 4 4 6 6 E e 8 10 12 14 15 • • • • •••••••• •• ••• • ••••••••••••••••••••••••••••••••••••••• • •••• •• ••• • • • • •• •• •• • ••• • •••• • •• ••• ••• • •• •• ••• ••• • •••• •••••• • ••••• ••• ••• ••• • •• •• • • • • • •••••• •••• • • ••• • • ••••• ••• •••• ••• •••• •••••• • ••• •• • ••• • • • ••• • • ••• • •••• • • •••• ••• •• Abstract Introduction . Description of area ••••••••••• Climate Data collection and analysis. Sediment discharge •••••••••• Sediment transport ,. Suspended-sediment concentration and discharge •••••••.•••.•••••• Relation between suspended-sediment discharge and water discharge. Bedload discharge and hydraulic characteristics ••••.••••••••••••• Relation between bedload discharge and water discharge ••••••••••• Estimated total sediment load . Summ.ary and conclusions ......•......•........................•. References ci ted . ILLUSTRATIONS •• ••• •••• •••• •• • • •• • • ••••••• ••••• •••• • •••• •• • • •• ••• • • ••• ••••• •••• • • • • •• •• ••• ••• • •• ••• • • • •••• • • •••• • • •• • •• ••• •• •••• ••• •• ••• •• ••• •••• ••• • • • • • • • • ••••• 2 30 31 32 16 17 18 19 20 21 22 23 24 25 26 27 2e 29 33 34 35 •• •• •••• • •••• ••••• • • •••••••• ••••• • ••• •• ••• ••• • • • ••••• ••• •••• • •• ••• • • • • • ••••••• • ••• •• ••• • • • Map showing location,major streams,and selected stream- gaging and sediment-sampling stations in the Susitna River basi t1 ••••••••••••••••••••••••••••••••••••••••••••••••••••• Graphs showing sediment-transport curves of suspended silt- clay and sand discharge for: Sus1tna River near Talkeetna . Chulitna River below canyon near Talkeetna •••••••••••••••••• Susitna River below Chulitna River near Talkeetna •••••••••• Talkeetna River near Talkeetna .. Susitna River at Sunshine . Yentna River near Susitna Station . Susitna River at Susitna Station . Graphs showing relation between suspended-sediment discharge and water discharge for: Susitna River near Talkeetna and at Gold Creek •.••••.••••••• Chulitna River below canyon near Talkeetna ••.••••••••••••••• Susitna River below Chulitna River . Talkeetna River near Talkeetna . Susitna River at Sunshine . Yentna River near Susitna Statio~.••..•....••..•..••••..••• Susitna River at Susitna Station . Graphs showing cross sections and distribution of bedload discharge: Susitna River near Talkeetna: a.May 17,1984 b.August 26.1984 •••••• c.September 25.1984 .•• Chulitna River below canyon near Talkeetna: a.May 18,1984 b.August 28,1984 c.September 27,1984 •••••. 17. 16. 2-8. 2. 3. 4. 5. 6. 7. 8. 9-15. 9. 10. 11. 12. 13. 14. 15. 16-22. Figure 1. iii ILLUSTRATIONS--Continued Page 18.Susitna River below Chulitna River near Talkeetna: 8.June 12,1984 .•..........................................36 b.August 27,1984 ...........•...................•........0.37 c.September :16,1984 ................•..••.•................38 19.Talkeetna River near Talkeetna: a.May 18,1984 0....39 b.August 26,19~4 •••••••••••••••••••••••••.•••••0.......40 c.September 26,1984 41 20.Susitna River at Sunshine: a.May 16,1984 .....•...•••....•............................42 h.August 25,1984 43 c.September 28,1984 44 21.Yentna River near Susitna Station 8.May 14,1984 ...........•......................•.......... c.September 19,1984 . 22.Susitna River at Susltna Station b.July 17,19~4 •••••••••••••••••••••••••••••••••••••••••••• 45 46 47 a.May 17,1984 ...........•.................................48 b.August 15,1984 49 c.September 20,1984 50 23-27.Graphs showing bedload-transport curves of sand and gravel for: 23.Susitna River near Talkeetna 51 24.Chulitna River below canyon near Talkeetns ••••••••••••••••••52 25.Susitna River below Chulitna River near Talkeetna ••••••••.••53 26.Talkeetna River near TBlk~etn8 ••..•.•.••••...••••••.•••.•..•54 27.Susitna River at Sunshine ..!................................55 28-29.Graphs showing bedload discharge of sand and gravel versus water discharge for: 28.Yentna River near Susitna Station 56 29.Susitna River at Sus:ftna Station 57 30-34.Graphs showing relation between bedload discharge and water 30.Susitna River near Talkeetlls 58 31.Chulitna River below canyon near Talkeetna •••••••••••••••••.59 32.Susitna River below Chulitna River near Talkeetna ••••••••.••60 33.Talkeetna River near Talkeetna..............................61 34.Sus:ftna River at SunshinE'62 35-36.Graphs showing bedload discharge versus water discharge for: 35.Yentna River near Susitna Station 63 36.Susitna River at Susitna Station............................64 iv TABLES Page Table 1.Summary of streamflow and sediment data for selected stations in the Susitna River basin ...••.•..•••...............•..•...65 2.Suspended-sediment data for selected stations in the Susitna River basin,October 1983 to September 1984 •••••••••••••••••66 3.Hydraulic and bedload data for selected stations in the Susitna River basin,October 1983 to September 1984 •••••••••68 4.Bed-material data for selected stations in the Susitna River basin,May to September 1984 ..........•.................•.•.70 5.Water discharge and estimated total sediment loads at selected stations in the Susitna River basin,October 1983 to September 1984 . . . . . . . . . . . . . . .72 CONVERSION TABLE For the convenience of readers who prefer metric (International System)units rather than the inch-pound units used in this report,the following conversion factors may be used: Multiply inch-pound unit to obtain metric unti inch (in.)25.40 millimeter (mm) foot (ft)0.3048 meter (m) mile (mi)1.609 kilometer (Ian) square mile (mi 2 )2.590 square kilometer (km 2 ) acre-foot (acre-ft)1,233 cubic meter (m s ) cubic foot per second (ft S Is)0.02832 cubic meter per second (m s Is) ton,short 0.9072 megagram (Mg) ton per day (ton/d)0.9072 megagram per day (Mg/d) degree Fahrenheit (OF)°C-5/9 (OF-32)degree Celsius (DC) Milligram per liter (mg/L)is a standard reporting unit for which no inch-pound equivalent is used. v vi SEDIMENT TRANSPORT CHARACTERISTICS OF SELECTED STFE~S IN THE SUSITNA RIVER BASIN, ALASKA,OCTOBEF 1983 TO SEPTEMBER 1984 By James M.Knott,Stephen W.Lipscomb,and Terry W.Lewis ABSTRACT The upper reaches of the Susitna River have been considered for development of a large power-generation system for southcentral Alaska.This report presents a summary and discussion of sediment and hydraulic data obtained from October 1983 to September 1984 at ten sites on the Susitna,Chulitna,Talkeetna,and Yentna Rivers. Sediment data include measurements of suspended-sediment and bedload discharge and analyses of particle-size distribution of suspended sediment,bedload,a.nd bed material;hydraulic data include measurements of width,average depth and velocity, and water-surface slope.Relations between water and sediment discharge are developed for selected sites. Sediment loads for the 1984 water year were estimated for the Yentna,Chulitna,and Talkeetna Rivers and for four sites on the Susitna River.About 25 million tons of sediment was transported by the Susitna River at Susitna Station during the 1984 water year.The Yentna and Chulitna Rivers contributed more than 20 million tons of sediment to the Susitna River. About 90 percent of suspended material (silt,clay,and sand)transported past upstream sites reached Susitna Station during 1984.However,only 56 percent of the transported coarse sand and gravel,as estimated for the upstream sites, reached Susitna Station during the same period. INTRODUCTION The Susitna River is one of the major rivers in Alaska,ranking fifth in drainage area.The upper reaches of the river are being considered as potential sites for several dams and reservoirs that would be part of a large power-generation system in southcentral Alaska. This report presents a summary and discussion of sediment and hydraulic data collected at selected sites in the Susitna River basin in the area between the proposed damsites and Cook Inlet (fig.1 and table 1).The data were collected during the period October 1983 to September 1984 as part of a cooperative program between the Alaska Power Authority and the U.S.Geological Survey.Selected data from Knott and Lipscomb (1983,1985)for the 1981-83 water years and the data collected in 1984 are used to estimate the total amount of sediment (suspended sediment and bedload)transported by the major rivers in the basin during the 1984 water year.An attempt is made to develop relations between water and sediment discharge for various sites in the basin. 1 2 I 147° EXPLANATION 3 A STREAM GAGING STATION (FLOW AND SEDIMENT DATA) AND MAP NUMBER 4 V SEDIMENT SAMPLING STATION AND MAP NUMBER DRAINAGE BASIN BOUNDARY OI-----,-1'-0,-----r.::.20_--,--3-',0,---....J40'----_J50 Ml LES 0 10 20 30 40 50 Kl LOMETEAS Figure I.-Location, major streams, and selected stream-gaging and sediment-sampling stations in the Susitna River basin. 3 DESCRIPTION OF AREA The Susitna River basin (fig.1)lies on the southern flank of the Alaska Range in southcentral Alaska.The relief of the basin,which has a drainage area of about 19,400 mi 2 ,is a contrast of steep rugged mountains towering above wide valley lowlands.Altitudes range from 20,320 ft at Mt.McKinley to sea level where the Susitna River empties into Cook Inlet. Tributaries to the Susitna River are commonly referred to as either glacial or nonglacial streams.The nonglacial streams are noted for their clarity,even during intense summer rainstorms.Glacial streams are turbid throughout most of the open-water season (May through September).The Susitna River and its larger tributaries are all affected to some degree by glacial runoff. CLIMATE The climate of the Susitna River basin is divided into two broad categories accord- ing to maps prepared by Searby (1968).The higher altitude parts of the basin are included in the Continental Zone,where diurnal and annual temperature variations are great.Mean annual temperature ranges from 15 to 25 OF (Hartman and Johnson, 1978).The lowlands lie in the Transition Zone where temperatures are less vari- able than in the Continental Zone.Mean annual temperatures generally range from 25 to 35 OF. Hean annual precipitation of the basin ranges from less than 20 in.near the mouth of the Susitna River to more than 80 in.at higher altitudes (National Weather Service,1972).Climatological records for the Talkeetna weather station are probably representative of lowland areas.A summary of climatological data for this station (Selkregg,1974)indicates that mean daily temperatures range from 38 to 62 OF in summer,and from -9 to 18,oF in winter;extremes range from -44 to 85 OF.Annual precipitation averages 28 in.,about 60 percent of which is rainfall. DATA COLLECTION AND ANALYSIS Beginning in 1981,systematic measurements of sediment discharge and hydraulic stream properties have been made to define the amount and distribution of sediment transported by the Susitna River and its major tributaries between Gold Creek and Sunshine (fig.1).In 1981,data were collected at four sites in July,August,and September.Two of the sites were on the Susitna River,one at Gold Creek (map No. 3)and the other at the Parks Highway crossing at Sunshine (map No.12).The remaining two sites were located on major tributaries to the Susitna River,one each on the Chulitna (map No.7)and Talkeetna Rivers (map No.11). During 1982 the data-collection program was expanded to obtain weekly samples during the open-water season (Hay to September).A new sampling site was estab- lished on the Susitna River,upstream of the Chulitna River confluence (map No.6). The stream-gaging station and the monthly collection of suspended-sediment samples were continued at Gold Creek.During 1983,bedload sampling sites were established on the Susitna River (map Nos.9 and 10)and during 1984 on the Susitna (map No. 14)and Yentna (map No.13)Rivers.Suspended-sediment data have been obtained for 4 the Susitna River at Susitna Station respectively (Still and Jones,1985). and Yentna River sites since 1975 and 1981, At each site,data collection included: 1)Suspended-sediment samples 2)Bedload samples 3)Bed-material samples 4)Water-discharge measurements 5)Measurements of depth and width Selected samples of suspended sediment,bedload,and bed material were analyzed for particle-size distribution.Streamflow characteristics were defined from data available for existing stream-gaging stations.At sampling sites that did not co- incide with stresm-gaging stations,sufficient discharge measurements were obtained to develop stage-discharge relations.Summer measurements were made from a boat; either a cableway or sextant was used to determine stationing along the measuring section.Winter measurements were made by attaching a sampler to a rod and lower- ing the sampler through holes drilled in the ice. Depth integrated,suspended-sediment samples were collected using a standard point- integrating P-61 sampler (Guy and Norman,1970).Samples include those particles (usually finer than 2.0 mm)transported in the stream between the water surface and a point about 0.5 ft above the streambed.Two samples were obtained at each of five selected verticals in the stream cross section (at centroids of flow)and analyzed to determine average values of suspended-sediment concentration and the particle-size distribution of sediment in the water-sediment mixture.The two samples from each vertical profile were generally composited to obtain one analysis,but in a few instances the individual samples were analyzed. Sediment transported within 0.25 ft of the streambed was sampled using a bedload sampler (Helley and Smith,1971)designed for collecting coarse material (0.25- 76.2 mm).Sampling time,number of sampling points,stream width and depth,and weight of dry sediment were recorded as a basis for calculating bedload discharge. Trap efficiency of the sampler was assumed to be 1.0.Characteristics of the Helley-Smith sampler and procedures for its use have not yet been fully evaluated. In the interim,the Geological Survey follows a provisional method of obtaining samples at about 20 equally spaced verticals based largely on field tests by Emmett (1980). Some of the sediment transported in suspension cannot be accurately sampled because the lowest depth accessible by the p-61 sampler is about 0.5 ft above the riverbed. Silt-clay concentrations are generally assumed to be uniformly distributed through- out the total depth of the river and the concentration of this material in the unsampled zone (between riverbed and 0.5 ft above bed)is considered to be approxi- mately the same as that in the sampled zone.The concentration of suspended sand in the unsampled zone,however,is generally larger than that in the sampled zone because sand particles tend to settle toward the riverbed if flow velocities are not sufficient to keep them in suspension.At least part of the medium to coarse sand fraction (0.25-2.0 mm)in the unsampled zone is trapped by the bedload sampler (from riverbed to 0.25 ft). 5 A preliminary examination of the amount of sand transported in suspension and as bedload (tables 2 and 3)suggest that attempting to account for unsampled sand would generally increase reported concentrations of suspended sand (table 2)at most sites by about 1 percent.At some sites,however,such as the Yentna River and the Susitna River at Susitna Station,the amount of sand transported in the unsampled zone is perhaps 10 percent of the total suspended sand. A few bed-material samples were obtained at each site using a 6-inch diameter pipe dredge.At some sites,deep water and a swift current,armoring,and the presence of coarse particles on the streambed made sampling difficult.Although indicative of the sizes of particles present in the streambed (less than 150 mm),bed-material data presented in this report may not be representative of actual particle-size distributions.Surface and sub-surface samples were also obtained where the stream- bed was exposed or where water depths were less than 2 ft.These samples,obtained with a sampler similar to a McNeil sampler (McNeil and Ahnell,1964)are probably representative of actual particle-size distributions. Measurements of depth and width at sampling sections were usually made during bedload measurements.Depths were measured by sounding wi th the Helley-Smith sampler at 16 to 25 verticals in the cross section.Stream width was determined from station markings on cableways or from sextant readings.Average velocity was determined by dividing the rated discharge of the stream by the cross-sectional area (width x depth). SEDIMENT DISCHARGE Sediment Transport Sediment is transported in suspension,by rolling and bouncing along the streambed, or as a combination of both.Suspended sediment,as the name implies,consists of particles that are transported in a stream while being held in suspension by the turbulent components of the flowing water.Coarse sediment that is transported on or near the streambed constitutes the bedload.Clay-and silt-size particles usually are moved in suspension and gravel particles move on or near the streambed. Sand-size particles may be transported either as suspended load,as bedload,or both. Suspended-Sediment Concentration and Discharge Suspended-sediment data for the period October 1983 to September 1984 are listed in table 2.Suspended-sediment concentrations for the winter (October to April)when the rivers are lowest are generally less than 10 mg/L.During 1984,spring breakup occurred at all sampling si tes in early May.Suspended-sediment concentrations through late May ranged from less than 5 mg/L for Portage and Indian Creeks to more than 400 mg/L at most sites on the Susitna,Chulitna,and Talkeetna Rivers.The amount of sand-size material (0.062-2.0 mm)was generally large relative to the finer silt-clay fraction (less than 0.062 mm)suggesting that sediment was supplied primarily from the erosion of stream channels by snowmelt. 6 Suspended-sediment concentrations at during the summer (June to August). during periods of storm runoff. individual sampling sites are most variable The larger concentrations typically occur The Susitna River near Talkeetna (map No.6)and the Talkeetna River near Talkeetna (map No.11)are least affected by glacial runoff;glaciers cover 5 and 7 percent of their respective drainage areas.Sampled concentrations at these sites ranged from about 200 to 1,000 mg/L,and averaged about 400 mg/L during June to August 1984.Suspended-sediment discharge of the Susitna and Talkeetna Rivers averaged 28,000 and 12,000 ton/d respectively. The drainage area of the Chulitna River above the sampling site (2,580 mi 2 )is about 40 percent as large as the drainage area of the Susitna River near Talkeetna. Twenty-seven percent of the Chulitna River drainage area is covered by glaciers. Summer concentrations of suspended sediment in the Chulitna River are typically more than twice as high (800 mg/L)as those for either the Susitna or Talkeetna Rivers near Talkeetna.Suspended-sediment discharge of the Chulitna River averaged 62,000 ton/d during June to August 1984 (see table 5 later in text). Suspended-sediment data obtained at the sampling site designated Susitna River below Chulitna River near Talkeetna (map Nos.9 and 10 for the right and left channels,respectively)are representative of the combined discharge of the Susitna River near Talkeetna and Chulitna River below canyon near Talkeetna (map No.8). The site,about 1 mi below the confluence of the Chulitna and Susitna Rivers, includes two major channels (separated by a stable,vegetated island)and several minor channels.At this site,the right channel (as viewed looking downstream)of the Susitna River carries the entire flow of the Chulitna River along with smaller but varying amounts of "crossover"flow from the Susitna's left channel.Suspended- sediment concentration and discharge for the right channel were typically several times higher than that of the left channel in the period June through August 1984. Suspended-sediment concentrations for the Susitna River at Sunshine ranged from 569 to 999 mg/L from June through August 1984.Suspended-sediment concentrations at this site represent the result of the mixing of the Chulitna,Susitna,and Talkeetna Rivers.Suspended-sediment discharge for the Susitna River at Sunshine, from June through August,averaged about 110,000 toni d which agrees closely with the sum of sediment discharges for the Chulitna,Susitna,and Talkeetna Rivers (102,000 ton/d). The Yentna River,with a drainage area of 6,180 mi 2 (above the gaging station)is the largest tributary to the Susitna River.Samples of suspended-sediment concen- tration ranged from 363 to 792 mg/L during June to August.Concentrations for the Susitna River at Susitna Station (563 to 700 mg/L)fall within the range in concentration for the Yentna River and Susitna River at Sunshine. Suspended-sediment concentrations and discharge usually decline during September and October as cooler weather reduces the melting rate of high-altitude snowpacks and glaciers.In 1984,no maj or storms occurred during this period and sampled concentrations of the si tes at Susi tna and Talkeetna Rivers near Talkeetna were less than 30 mg/L.Concentrations for the Chulitna and Yentna Rivers declined 7 substantially below summer values but remained greater than 100 mg/L by late September. Relation Between Suspended-Sediment Discharge and Water Discharge A common method for analyzing sediment-transport characteristics at a site is to construct a graph of sediment discharge versus water discharge.This relation is generally illustrated by a plot on logarithmic paper and is referred to as a sedi- ment-transport curve.Data for May to September 1982-84 reported in Knott and Lipscomb (1983 and 1985)and in this report were used to develop transport curves for the silt-clay and sand size fractions of suspended sediment for the Susitna, Chulitna,and Talkeetna Rivers (figs.2-6).Historical data (u.S.Geological Survey,1975-84)were used to develop similar curves for the Susitna and Yentna Rivers near Susitna Station (figs.7-8).Coefficients of determination (r 2 )were computed from a least-squares fit of log-transformed values to provide a measure of the variance of sediment discharge to water discharge.The transport curves for suspended sediment should be considered representative only for the period of open water (May to September).Particle-size data obtained for samples collected in winter periods (October to April)are too few to construct similar curves. The transport curves of silt-clay size material for all sampling sites near Talkeetna show a similar trend;that is,the silt-clay size discharge increases at a similar exponential rate relative to increases in water discharge.Exponents of water discharge,Q,in the relations (figs.2-5)ranged from 2.86 to 3.14;r 2 ranged from 0.74 to 0.93.The increase in silt-clay size discharge relative to increases in water discharge is considerably smaller for sampling sites on the Yentna River and Susitns River at Sunshine and Susitna Station (figs.6-8).The progressive decrease in exponents from Talkeetna to Susitna Station may be due to lags in peak sediment concentration relative to peak water discharge or to an increased distance from sediment sources. Transport curves for suspended sand-size material indicate a larger variation in exponents than those for silt-clay size material (fig.2-5).Exponents of water discharge for sites near Talkeetna range from 2.21 to 3.39;r 2 values range from 0.86 to 0.88.The trend of decreasing exponents with distance downstream from Talkeetna also occurs for the transport of suspended sand. Transport curves of total suspended-sediment discharge for winter periods (October to April)were prepared from recent historical data (figs.9-15).Pre-1975 data generally were excluded from the analyses because of apparent shifts in transport relations for several rivers following the extremely wet year of 1971.Because of the paucity of suspended-sediment data for winter months,most relations between water and suspended-sediment discharge for October to April periods Bre not well defined. Bedload Discharge and Hydraulic Characteristics The bedload and hydraulic data for the sampling sites are summarized in table 3. Bedload data are expressed both as discharge in tons per day,and in terms of their particle-size distribution in percent finer than the indicated sieve size. 8 Winter samples (through ice cover)of bedload have been collected twice at most sites --once in March 1983 and again in February 1984.Bedload discharges computed from samples collected in February and March probably indicate near-minimum rates of transport because these are the months of minimum streamflow.Fedload discharges of the Chulitna.Susitna.and Talkeetna Rivers near Talkeetna were extremely low. ranging from zero to about 2 ton/d.In February 1984.bedload discharge of the Susitna River increased to 52 ton/d at the site "below Chulitna River near Talkeetna"and to more than 200 ton/d at Sunshine.Bedload at all sites was pre- dominantly sand during the winter.but large amounts of gravel were transported at sampling sites on the Chulitna River and the Susitna River at Sunshine (table 3). During the 1984 open-water period.bedload discharge of the Susitna River near Talkeetna ranged from 14 to 894 ton/d (table 3).During this same period.water discharge ranged from 8.460 to 40.900 ft'/s.The transported material consists primarily of sand (81-100 percent)and lesser fractions of gravel (0-19 percent). Bedload discharge of the Chulitna River below the canyon ranged from 2.090 to 6.590 ton/d and water discharges ranged from 7.480 to 23.300 ft'/s.During low-flow periods in May and September.the particle-size distribution of bedload on the Chulitna River tended toward a high percentage of sand (63-87 percent).Gravel was the primary constituent of the bedload (52-69 percent)during the summer. During the open-water period.bedload discharge of the Talkeetna River near Talkeetna ranged from 48 to 2.690 ton/d for water discharges ran~ing from 2.900 to 23.400 ft'/s.Typically.the bedload at this site consisted mainly of sand (70-99 percent).The percentage of gravel exceeded that of sand only during the high flow of August 26.1984. Bedload discharge at Susitna River below the Chulitna River was measured separately in each of two major channels about 1 mi downstream from the confluence.Bedload transport rates in each channel roughly correspond to rates measured at upstream sites on the Chulitna and Susitna Rivers near Talkeetna.A large part of the water discharge.however.crosses over from the Susitna River and mixes with flow originating from the Chulitna River.Bedload transport rates in the right channel are similar to those measured at the upstream Chulitna River site.Transport rates ranged from 652 to 12.200 ton/d with gravel constituting about 50 to 80 percent of the bedload.Bedload during low flows was predominantly sand (60-80 percent). Bedload rates in the left channel are typically much lower than those in the right channel and are similar to those measured at the Susitna River near Talkeetna. Bedload ranged from 18 to 1.430 ton/d with sand comprising about 70 to 90 percent of the bedload. Bedload discharge of the Susitna River at Sunshine ranged from 1.190 to 3.590 ton/d at flows ranging from 17.800 to 99.700 ft'/s.Sand and gravel fractions generally varied with water discharge.During low flows the bedload mixture was about 80 to 90 percent sand and 10 to 20 percent gravel.During the summer.the percentage of sand was generally about 60 percent.except for the high flow of August 25 when 80 percent of the bedload was sand.The bedload was predominantly sand during winter measurements. 9 Bedload measurements for the Yentna and Susitna Rivers near Susitna Station were initiated in 1984.The Yentna River transported a large amount of bedload (6,800-11,300 ton/d)but the range in quantity of bedload transported was small; low flows seem to transport as much bedload as do higher flows.Most of the bedload was sand (85-91 percent).Bedload transported by the Susitna River at Susitna Station during 1984,ranged from 3,250 to 8,590 ton/d and was also mostly sand (76-96 percent).The amount of bedload sand transported past Susitna Station is lower than that of the Yentna River.Because the Susitna River above the confluence of the Yentna River also contributes a considerable amount of similar material,a large part of the bedload sand measured at the upper sites may be transported past Susitna Station as suspended sediment,may be deposited between the sites,or may be moving at very slow velocities relative to the water.Recent studies by Emmett and others (1983)indicate that bedload may move at speeds of 0.01 to 0.1 percent of the mean velocity of the flow. Channel cross sections for selected sites,with a corresponding plot of bedload discharge at individual sampling points,are shown on figures 16-22.In most cases maximum bedload movement occurs in the zone between the thalweg (maximum channel depth)and the mid-channel. The volume of bedload material at individual sampling points was visually estimated and converted to equivalent weight during sampling.Individual samples were composited for sieve analyses.The estimated weights were used,together with the actual weight of the composited sample,to give an estimate of bedload for each sampling point. Relation Between Bedload Discharge and Water Discharge A relation between bedload discharge and water discharge can be defined using methods similar to those for suspended sediment.Log-transformed data and a least- squares analysis were generally used to obtain a best-fit line through the plotted points.Transport curves and corresponding equations describing the relations are shown in figures 23-36. The line of best fit for the transport curves,as computed by the least-squares method,provides a reasonable relation between sand or gravel discharge and water discharge for most of the monitoring sites.The relations generally indicate that sand and gravel discharge increase with corresponding increases in water discharge. The scatter of data points about the fitted lines,however,varies widely from site to site,suggesting that bedload discharge is influenced by factors other than water discharge.The other factors probably include hydraulic characteristics of the river (depth,width,velocity,slope),particle size,the available supply of coarse sediment,and time lags between the movement of coarse material and runoff. Part of the scatter of the data may also be due to sampler bias.The Helley-Smith sampler is generally considered to be in the experimental stage of development. Relations between water and bedload discharge are less reliable than those for suspended sediment.Relations with coefficients of determination larger than 0.5 are shown as solid lines.Dashed lines are used for relations with coefficients of determination that are smaller than 0.5 or for relations obtained by a visual fit. 10 The line of best fit,computed by the least-squares method,provides a reasonable relation between bedload and water discharge from the Susitna River near Talkeetna (fig.23).The scatter of data points about the line is small and is uniform for the entire range of flow. Bedload data for the Chulitna River have an extremely large scatter (fig.24).The distribution of the data is unusual in that bedload appears to increase with increasing discharge at relatively low flows and then decrease at higher flows. Decreases in bedload occur abruptly at flows of 17,000 to 18,000 fts/s and at 28,000 to 30,000 fts/s,indicating a reduced supply of coarse sediment at the sampling site.A preliminary analysis of the data for seasonal trends suggests that part of the variability in bedload transport is due to a time lag between bedload and water discharge.A maj or change in channel shape occurs about 8 mi upstream from the sampling site.At this point,the river is constricted to a narrow canyon.The supply of bed material in the canyon is small relative to that available in an extensive braided channel reach upstream from the canyon. Comparisons of periods of high bedload transport with hydrographs of stream discharge indicate that coarse sediment requires about 20 to 40 days to travel from the head of the canyon to the sampling site compared to several hours for the water to travel the same distance.If the extreme variability in bedload is assumed to be largely the result of changes in the supply of coarse sediment,some approximate relations between bedload and water discharge can be developed. Three-relations were estimated for the transport of sand and gravel at the Chulitna River sampling site.The relations for low flow (7,000-17,500 fts/s)were obtained by least-squares analysis.These relations are assumed to represent a general steady-flow condition during which the supply of coarse sediment above the canyon is in equilibrium with the supply passing the sampling site.The transport rela- tions for high flows (greater than 29,000 ft 3 /s)were estimated by shifting the slope of the low-flow relations to represent a minimum sediment supply at the sampling site.Transport relations for intermediate flows were obtained by averaging the relations for low flows and high flows. Bedload data for the Susitna River below Chulitna River (fig.25)have a large scatter,but the data indicate a rough trend of increased bedload with increases in discharge.The relations between sand and gravel discharge and water discharge were obtained by least-squares analysis. Bedload-transport relations for the Talkeetna River (fig.26)are reasonably well defined and generally indicate a large exponential increase in bedload with water discharge,similar to that for the Susitna River near Talkeetna.Least-squares analysis was used to obtain the transport curve for gravel.The transport curve for sand discharge was obtained by visually fitting a straight line through the data.The average relation between bedload sand and water discharge is obscured by the repeated occurrence of high bedload lagging behind periods of storm runoff. The large displacement of the data,relative to the trend of most of the points, suggests that the supply of coarse sediment is highly variable during some periods. Bedload data for the Susitna River at Sunshine (fig.27)have a large scatter;the pattern of variability generally corresponds to that of the Susitna River below Chulitna River. 11 Bedload data for the sampling sites Yentna River near Susitna Station and Susitna River at Susitna Station (figs.28-29)are considered insufficient to define a relation between bedload and water discharge.Comparison of the data with transport relations for Susitna River at Sunshine,however,suggests that the discharge of sand and gravel increases at small exponential rates with increases in discharge.Transport curves of total bedload discharge (figs.30-36)for suamer periods (May to September)were developed by combining curves for sand and gravel. A few samples of bed material were collected from May through September 1984. Analyses of these samples are listed in table 4.Samples representative of the sediment present in submerged parts of the channels were extremely difficult to obtain because the rivers were too deep and swift for direct access to streambeds. Samples considered representative of particles finer than 128 mm,however,were obtained at most of the sampling sites. ESTIMATED TOTAL SEDIMENT LOAD The sediment load from a drainage basin is commonly expressed in terms of weight (short or metric tons)or volume (acre-feet or cubic meters).Sediment loads may be estimated by different methods,depending on the amount and type of available data.If daily records of streamflow are available,but sediment discharge has been measured only infrequently,the method most commonly used requires defining a relation between instantaneous sediment discharge and water discharge and applying this relation to daily values of water discharge.This method was used initially to estimate sediment load for this study.At some sites,however,a single sediment-transport curve could not be applied for the open-water period because of seasonal changes in the amount and particle-size distribution of sediment for given water discharges.At the "Chulitna River below canyon"site,the scatter of bedload-discharge data was such that even the definition of a bedload-water discharge relation is subjective.Thus,several alternative methods were selected to estimate sediment load for the 1984 water year. Suspended-sediment loads were estimated uaing the Colby shift-control method (Colby,1956).According to Colby,part of the scatter of sediment data in sediment transport relations is due to random or very short-term fluctuations in concentration,particularly the concentration of the coarse sediments.Part of the scatter may be due to an actual change that may persist for days,weeks,or seasons.If it is assumed that most of the observed scatter is due to seasonal changes and complex mixing of sediment produced from glacial melt and storm runoff, Colby's method would produce the most accurate estimates. Colby suggests that if a change in the relation between water and sediment dis- charge persists for several days or more,the transport curve should be shifted to pass through or near each individual measurement.The method is subjective because judgment is used to decide whether the measurement is representative of an actual change or of a random fluctuation.An important advantage in using this method is that the accuracy of fit of the transport curve is of small importance. Bedload also was estimated using the Colby shift-control method.At sites on the Chulitna and Talkeetna Rivers where the scatter in bedload-discharge data was extreme and regression equations did not fit the data,the initial transport curve 12 was estimated by a visual best-fit of the data. constructed for silt-clay,sand,and gravel size sediment and bedload discharge measurements. Sediment-transport curves were components for both suspended Estimated total sediment loads for the 1984 water year are summarized in table 5. Monthly and annual loads are given for four sites on the Susitna River and for one site on each tributary,the Chulitna,Talkeetna,and Yentna Rivers. Total sediment load (sum of suspended load and bedload)of the Susitna River increases from 3.1 million tons in the middle reach of the river near Talkeetna to more than 25 million tons near the mouth at Susitna Station.The Chulitna, Talkeetna,and Yentna Rivers account for most of the increase,contributing 7.2, 1.2,and 12.9 million tons,respectively. Suspended load of the Susitna River and its tributaries ranged from about 91 to 98 percent of the total load during 1984.A large part of the suspended load con- sisted of silt-clay size material (less than 0.062 mm)which is easily held in suspension and is generally transported large distances at nearly the same velocity as the flowing water.It is unlikely that any appreciable deposition occurs in the reach from Talkeetna to Susitna Station because the monthly amount of silt-clay size material transported at upstream sites is about the same as that transported at downstream sites.Similar comparisons for suspended-sand loads also show a good agreement in the amount of this material transported at upstream and downstream sites. Bedload,which generally consists of medium sand to very coarse gravel (0.25-64.0 mm)at most sites,is subject to large variations in transport rate,depending on flow characteristics and the available supply of coarse sediment. Annual bedload transport at the various sampling sites during 1984 ranged from about 50,000 to 1.2 million tons.Annual bedload was smallest at Susitna River near Talkeetna and largest at Yentna River near Susitna Station.Medium to coarse sand accounted for more than 80 percent of bedload at each sif.e.The Chulitna River near Talkeetna transported about 630,000 tons during 1984;most of which was fine to coarse gravel (2.0-64.0 mm). The small number of samples obtained for the Yentna and Susitna Rivers near Susitna Station in 1984 is considered insufficient to determine an average relation for estimating monthly bedload.An estimate of seasonal bedload was made,however,by averaging the individual measurements.Measurements obtained during the open-water period showed little change with water discharge.Two bedload measurements obtained during February and April 1985 were averaged to estimate the amount of bedload transported during the winter (October to April). 13 SUMMARY AND CONCLUSIONS The total sediment load of the Susitna River near its mouth (at Susitna Station) during the 1984 water year was estimated to be about 25 million tons.This estimate,as well as estimates of sediment load for other sites on the Susitna River and its tributaries,are based primarily on measurements of suspended- sediment and bedload discharge made during the 1982-84 water years.Suspended- sediment data collected in winter periods prior to 1982 were used to develop sediment-transport relations for sites at which the 1982-84 data were insufficient. Estimates of total sediment load for the major tributaries of the Susitna River and the Susitna River near Talkeetna site account for most of the sediment passing Susitna Station,the farthest downstream sampling site.The Yentna and Chulitna Rivers contributed about 20 million tons of sediment,or 80 percent of the total for the 1984 water year.The Susitna and Talkeetna Rivers accounted for an additional 4 million tons of sediment during the same period.The combined drainage area of the above sites is about 17,000 mi',or 88 percent of that for the Susitna River at Susitna Station. About 90 percent of the suspended material (silt,clay,and sand)transported past upstream sites reached Susitna Station during 1984.However,only 56 percent of the coarse sand and gravel estimated to have been transported past the upstream sites reached Susitna Station during the same period. Sediment-transport relations developed in this report for many of the sampling sites should be considered provisional.Relations developed between water and suspended-sediment discharge generally provide a reasonable fit to the data except for winter periods,when few data are available.Relations between water and bedload discharge are less reliable than those for suspended sediment. 14 REFERENCES CITED Colby,B.R.,1956,Relationship of sediment discharge to streamflow:U.S.Geo- logical Survey open-file report,170 p. Emmett,W.W.,1980,A field calibration of the sediment-trapping characteristics of the Helley-Smith bedload sampler:U.S.Geological Survey Profeasional Paper 1139,44 p. Guy,H.P.,and Norman,V.W.,1970,Field methods for measurement of fluvial sediment:U.S.Geological Survey Techniques of Water Resources Investigations Book 3,Chapter C2,59 p. Hartman,C.W.and Johnson,P.R.,1978,Environmental atlas of Alaska (2nd ed.): University of Alaaka,Institute of Water Resources,95 p. Helley,E.J.,and Smith,Winchell,1971,Development and calibration of sure-difference bedload sampler:U.S.Geological Survey open-file 18 p. a pres- report, Knott,J.M.,and Lipscomb,S.W.,1983,Sediment discharge data for selected sites in the Susitna River basin,Alaska,1981-82:U.S.Geological Survey Open-File Report 83-870,45 p. 1985,Sediment discharge data for selected sites in the Susitna River basin,Alaska,October 1982 to February 1984:U.S.Geological Survey Open- File Report 85-157,68 p. McNeil,W.J.,and Ahnell,W.H.,1964,Success of pink salmon spawning relative to size of spawning bed materials:University of Washington,Fisheries Research Insitute Report 469,14 p. National Weather Service,1972,Mean annual precipitation--inches: Weather Service [Alaska],map. National Searby,H.W.,1968,Climates of the States --Alaska:Environmental Data Service ESSA,Climatology of the United States,No.60-49. Selkregg,L.L.,editor,1974,Alaska regional profiles --southcentral region: University of Alaska,Arctic Environmental Information and Data Center,255 p. Still,P.J.,and Jones,K.V., records to September 30, 85-332,173 p. 1985, 1983: Alaska U.S. index:Streamflow Geological Survey and water-quality Open-File Report U.S.Geological Survey,1975-84,Water resources data for Alaska:U.S.Geological Survey Water-Data Reports. 15 o Osand =1.01 x 10,1103 .39 r 2 =0.86 100,000 f-•1982•1983 0 1984 0 Stream discharge >-LOs+c Silt-clay discharge« Cl Osand Sand discharge a::w ll. Vl Z 0 10,000f- Z-~w-Os+c=7.41 x 10.1003.01 <.:la::r 2 =0,74« I U Vl Cl I /•f- Zw :2 Cl....w cr-Vl Cl 1000w Cl Z W ll.~Vl 10·::> Vl o o 100,00010,000 100 I I I I I I I !J I I I I I I I I ! I 1000 10,000 100,000 1000 WATER DISCHARGE,IN CU81C FEET PER SECOND Figure 2.--Sediment-transport curves of suspended silt-clay and sand discharge for Susitna River near Talkeetna,May to September,1982-84,(Map number 6) 1,000,000 ...... " •1982 •1983 o 1984 o Stream discharge >-LOs+c Silt-clay discharge ~Osand Sand discharge II: UJc.. en L Os+c =1 51 x 10-8 0 2 .86z. ~100,000 r 2 =0.93 z UJ ~ II:« Iuen o I- Z UJ ~ o UJen 6 10,000 UJoz UJc..en ::Jen .~ Osand =9.80 x 10-70 2.38 r 2 =0.87 • o • / 100,00010,000 1000,J I I I J I I , I1000- - -J I I I I !1 I_~ WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 3.--Sediment-transport curves of suspended silt-clay and sand discharge for Chulitna River below canyon near Talkeetna,May to September,1982-84.(Map number 8) 1,000,0001 I I i I I I I I I I Iii i I I I i ...... 00 >-«o a:wc.. CJ) Zo f- Z w ~a:« :I: U CJ) o f- Zw ~ ow U?owozwc.. CJ) ::::J CJ) 100,000 10,000 ..1983 o 1984 o Stream discharge Os+c Silt-clay discharge Osand Sand discharge Os+c =1.17 xl 0.1003 .14 r 2 =0.86 o & o ~ ~ Osand =1.50 x 10-60 2 .21 r 2 =0.86 0/& o 1000 I I I I r I I J I I I I !I I I I I I 1000 10,000 100,000 1000 WATER DISCHARGE,IN CUBIC FEET PER SECOND 10,000 100,000 Figure 4.--Sediment-transport curves of suspended silt-clay and sand discharge for Susitna River below Chulitna River near Talkeetna (sum of right and left channels),May to September,1983 and 1984.(Map numbers 9 and 10) 40,000 A 0.0• o o A Osand =4.78 x 10-7 0 2 .50 r 2 =0.88 AI••.., Ar;J'"o•• o •• Os+c =5.49 x 10-90 2.95 r 2 =0.76 , A o .1. •-I r /.°1 •1982100I--~1983 ---1 f-/0001984•0 Stream discharge Os+c Silt-clay discharge 0 Osand Sand discharge 1000 10,000 >-«o a:w c.. enzo t- Z w (,9 a:« Iuen o t- Zw :2: owen owozw c..en ::)en I-' \0 201 1 I I 1 I I 1 I I I I 1 I I I I I I 1000 10,000 100,000 1000 10,000 100,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 5.·-Sediment-transport curves of suspended silt·clay and sand discharge for Talkeetna River near Talkeetna, May to September,1982-84.(Map number 11) o 6. o Osand =6.85 x 10-60 2.05 r 2 =0.80 • 6. •1982 ..1983 o 1984 o Stream discharge ~[os+c Silt-clay discharge o Osand Sand discharge a:w 0-~L Os+c =5.88 x 10-90 2 .74 2 100,000 r 2 =0.81 z 1,000,000 I "I I I I r I I "",I iii w l?a: <I: I U Vl o f- Zw ~08I Vl ~10,000 r=/0 6. z W 0- Vl ::J Vl No o 1000,~~~__L'__...JI__--.JIL....L.I---l'--1ILl'~I-;'~,,IL__L_L-l~LUUJ1000-~---I'I ,'_'_'_'. WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 6.--Sediment-transport curves of suspended silt-clay and sand discharge for Susitna River at Sunshine,May to September,1982-84.(Map number 12) -I,--- 1,000,000100,000 Osand =1.74 x 10-3 0 1.57 r 2 =0.91 .1. •••• o •• Figure 7.--Sediment-transport curves of suspended silt-clay and sand discharge for Yentna River near Susitna Station, May to September,1981-84.(Map number 13) 1000 II I I I I I I I I I 'I I I I I I I I 10,000 100,000 1,000,000 10,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND 1,000,000 l-•1981·83 0 1984 0 Stream discharge Os+c Silt-clay discharge >-r Qsand Sand discharge •« Q 0:: Wa.. (J) Z 0 100,000I- Z E •-Iw t9 000::« ::I: U (J)- 0 I- Z N W I--'~ 0 10.000 l /Os+c =1.64 x 10-7 0 2 .45 w Cf?r2 =0.940•w 0 Zwa.. (J) ::J (J) 1,000,000 iii iii Iii i j i I I I Iii I 1,000,000 Osand =1.23 x 10-2 0 1.36 r 2 =0.63 •••." •• 100,000 • o I.e-. tI. o•• • o.·0 • Os+c =1.25 x 10-7 0 2.38 r 2 =0.85I• ~.0.1• ~• ~ • • • --.. •1975-83 o 1984 • o Stream discharge Os+c Silt-clay discharge Osand Sand discharge II: Figure 8.--Sediment-transport curves of suspended silt-clay and sand discharge for Susitna River at Susitna Station, May to September,1975-84.(Map number 14) 1000 I I I J I I I I I I I I I I I I I I I 10,000 100,000 1,000,000 10,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND 10,000 100,000 >-«o 0:: L.Uc.. (f) Zo f- Z L.U (;l 0::« I () (f) o I- Z L.U ::2: o L.U CJ?o L.Uo Z L.Uc.. (f) ::J (f) N N 1,000,000 Susitna River at Gold Creek >-«o ex: UJa.. CJ) Zo f- Z UJ (:J ex:« I () CJ) o f- Z UJ ~ o UJ CJ)o UJo Z UJa.. CJ) ~ CJ) 100,000 10,000 1000 100 10 X 1977-83 (Oct.-April) •1982 j •1983 (May-Sept.) o 1984 o Stream discharge Os Suspended-sediment discharge ~ / / X I / X I xl /;>x /XX ~ Susitna River near Talkeetna Os =4.11 x 10-1003.12 r 2 =0.87 Os =6.58 x 10-7 0 2 .22 1 1 I I 1111111 !I 1111111 I I 1111111 I I 1111111 100 1000 10,000 100,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 9.--Relation between suspended-sediment discharge and water discharge for Susitna River near Talkeetna,May to September,1982-84 (map number 6)and Susitna River at Gold Creek,October to April, 1977-83.(Map number 3) 23 100,000>-«offi 10,000a.CJ'l Zo f- Z 01 / j / / X X /Os =3.43 x 10-6 0 2 .26 t / X X Os =1.82 x 10-7 0 2 .66r2=0.94X1969-83 (Oct.-April)•1982 j~1983 (May-Sept.)o 1984oStream dischargeOsSuspended-sediment discharge 10 100 1000 UJ <.:J 0:«::r:u CJ'l o f- Z UJ ~ o UJ V?o UJo Z UJa. CJ'l ::> CJ'l 1 L..----l--L-.l--L--L..L.LJ'--'-----------'-_LI--l1--l1---L1...u1ILL'I I I I I I I I 100 1000 10,000 100,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND 1,000,000 ,. Figure 10.--Relation between suspended-sediment discharge and water discharge for Chulitna River below canyon near Talkeetna,May to September,1982-84 and October to April,1969-83.(Map number 8) 24 1cOOO,OOO L:I I I I I I I I r [iii iii I i I I f I I I I I I I I I I II 100,000 >-«o c:w 10,000 a.. (f) Zo I- Z w ~c:« G 1000 (f) o I- Z LlJ ~ o LlJ (J') 6 LlJ o 100z LlJa.. (f) ~ (f) 10 •o o Os 1983 ~(May-Sept.) 1984 ) Stream discharge Suspended-sed i ment discharge Os =2.46 x 10-8 0 2 .69 r 2 =0.91 o ~= 1,000,000 1 1 1'1111111 I 11111111 I 11111111 I 11111111 100 1000 10,000 100,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure ll.--Relation between suspended-sediment discharge and water discharge for Susitna River below Chulitna River near Talkeetna (sum of right and left channels),May to September,1983 and 1984.(Map numbers 9 and 10) 25 100,000 X 1975·83 (Oct.-April)•1982jA1983 (May-Sept.)o 1984oStream dischargeOsSuspended-sediment discharge o• •Os =1.86 x 10-7 0 2 .67>-<I:Cla:wc..(/) Zo I- Z w (;J a: <I: I t.) (/) Cl I- Zw ~ Clw (/) Clw Cl Zw c.. (/) ::J (/) 10,000 1000 100 10 •r 2 =0.85 Os =2.68 x 10-6 0 2 .27 11'=-OO~---'------'----'----'--'----LL~OL.:--_L-..l..-..L-l-Lli.lJL--,-_L-...L....LJ--.LJi..LL-_.L-..l...-...LJLUUlJ 1 00 10,000 100,000 1,000,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 12.--Relation between suspended-sediment discharge and water discharge for Talkeetna River near Talkeetna,May to September,1982-84 and October to April,1975-83.(Map number 11) 26 X 1981·83 (Oct,-April) •1982)A 1983 (May-Sept.) o 1984 a Stream discharge Os Suspended-sediment discharge 100,000 1,000,000 L 1 I I I I I I I I I I I t I Iii i I I I I I I I I I I I I I i I as =6.32 x 10-1002.99 ~>-« 0 a:: LlJ 10,000c... CJl Z 0 f- Z LlJ' (:J a::« I 1000u CJl 0 f- Z LlJ 2: 0 LlJ CJl 6 LlJ 0 100z LlJc... CJl ::J CJl 10 0, ..Os =3.42 x 10-7 0 2 .42 r 2 =0.87o 'i / f I I I / I X XI xl ! xl , I I I I I'I I I I I I I I I I I I I , I I I I I I I I ,I I I I I I I I 100 1000 10,000 100,000 1,000,000 Figure 13.--Relation between suspended-sediment discharge and water discharge for Susitna River at Sunshine,May to September,1982-84 and October to April,1981-83.(Map number 12) 27 1,000,000 c--,---,-T1TTTTl,----,---,.-T1-rTTTT--,-.-T1--rlor,--,----,--,------,r-r1n-n100,000 X 1981-83 (Oct.-April)e 1981-84 2 (May-Sept.)o 1984 )Q Stream dischargeOsSuspended-sediment discharge o 1,000,000 Os=5.76x 10-1203.61 e; / / / / /xi / / / X 10 100 1000 1 '--'------'----'--I......JL-L...L....l-'-------'-----'---'---...J.--'-L....l--'-L..-__L--....II--'-'--,--IL-LI1-'-1..1II 100 1000 10,000 100,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 14.--Relation between suspended-sediment discharge and water discharge for Yentna River near Susitna Station,May to September,1981-84 and October to April,1981-83.(Map number 13) 10,000>-«0a:wa..(/)Z 0~ Z w <.:) a:« I U (/) 0 f- Z ~I w ~ Ikl 0 W ~\CJ? 0w 0 Zwa.. (/) :::> (/) 28 1,000,000 L:r I I I I I I I I I I IIIIII I Iii IIII1 _I I I Ii IIII Stream discharge Suspended-sed iment discharge >-«o 0:: UJ Q.. (j) Zo ~ z UJ ~ 0::« I U (j) o ~z UJ ~ o UJ (j) 6 UJoz UJ Q.. (j) =>(j) 100,000 10,000 1000 100 X 1975·83 (Oct.·April) •1975·83 l (May·Sept.) o 1984 ) Q Qs tit Qs =1.36 x 1O-4 Q 1 .82 • r 2 =0.83 'X. J X I / / / I I Qs =1.27 x 10.9 0 2.81 Xl X:j X \~fij/ ~ 10 1,000,000 "I 111/1111 1'1111111 I 11111111 I 1'111111 100 1000 10,000 100,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 15.--Relation between suspended-sediment discharge and water discharge for Susitna River at Susitna Station,May to September,1975-84 and October to April,1981-83.(Map number 14) 29 95 ,I ,I I I I ~-UJ ~ UJ ::> LL ~ Z <!90- 0 z >-o 0: -<!~0:~~85 UJ CO ...I 0: UJ <!Discharge =17,800 cubic feet per second •Measurement <.10 10,••I , • • I I I I.I , • • • •••I I o 100 200 300 400 500 600 700 DISTANCE FROM LEFT BANK IN FEET Figure 16a.--Cross section and distribution of bedload discharge,Susitna River near Talkeetna,May 17,1984. (Map number 6) 80 I J I I I I 100 I ,I I I 1 I w l? 0:>- <!<! I 0 U 0:~Wo0- o en <!Zo0 ...If- o Zww wo ,....._-----,._._. 100iii iii I I 80'I I I I I I I 700600500400300200100 Discharge;40,900 cubic feet per second I I I I I I •Measurement <10 I--- r-- f-- f-- f-- f-- r-- f-- f-- -I ~I I I T J o DISTANCE FROM LEFT BANK IN FEET Figure 16b.--Cross section and distribution of bedload discharge,Susitna River near Talkeetna,August 26,1984. (Map number 6) I-~95 tt:::l u.I- Z «- Qz>-90 o II:- «I-II:«I-> -~~85 w « 200 >-« Q II: W (L 100 UlzW0t-'I- ~ w· t) II:« I U Ul 0 Q« 0 .....I Qw CD 10 95,------...",---------,1---------.1---------.-1-.------,1--------.I;jiw:::)lL .....Z <l:90~_ az>-----------Q~.....0:~!:::85-1j ~Discharge;8,460 cubic feet per secondW<l:80100w' <.:J 0:>- <l:<l: I au0:V)wa"- a V) <l:Z a 0 ...I ..... a z w OJ J 1 i 1 I •Measurement .(10 -- 600500200300400 DISTANCE FROM LEFT BANK IN FEET 100 10 L--.-.-.-.-.-.--L..--a-__f---W~__.___.--.___~__~_tt__L_tl__----...J o Figure 16c.--Cross section and distribution of bedload discharge,Susitna River near Talkeetna, September 25,1984.(Map number 6) 32 -7 .~~~ <00 •Mea'OJrement «10 - : - - - - i , I I••••1 100 200 30n DISTANCE FROM LEFT BANK IN FEET Fi~c 17a.--Cross section and distribution of bedload dischaq{p, Chulitna River below canyon near Talkeetna, May 18,1981./Map number 8) "Lo >•a "w•"z 0 ~ ~ w· 0 "<"0I Uw 0 0< 0 ~ 0 W• 33 95'I----~-t!;~90w0""z.~z >o II:1:15-•""> "w •iii ~80 I ----~---~Djs~harge =17,900 cubic feet per lecond75---1 L 12000~---- •Measu,ement <10 1000 =- - \I we "<X:100r ~ o I ~r T - - I 1 j 100 1C'--<.-........e-JLL o :too 300 DISTANCE FROM LEFT BANK IN FEET Figure 17b,--Cross section and distribution of bedload discharj;(e, Chulitna River below canyon near Talkeelna, Au~ust 28,1984.(l\.lap numher S) 34 \ I 95 I i I I I oo~j f--LIJ ~ LIJ :J lL f- Z «_ 0 Z >-o a::- « I-a::«I-:>-w IXl ..J a:: w « 85 80 Discharge ~7,100 cubic feel per second 75!I I I I f--I I I - f-- f-- f--•Measurement <10 - f--- -- -- -- I---f-- f-- f-- f--- r-- f-- '-- -- ____-I II T...1 ...-....--~-- 1000 >-« 0 a::w 0.. Ul Z 0 f- ~ W CJa::« I 100 (.) (/) 0 0« 0 ..J 0 UJ III 10 o 100 200 300 400 I' ! \ DISTANCE FROM LEFT 8ANK IN FEET Figure 17c.--Cross section and distribution of bedload discharge, Chulitna River below canyon near Talkeetna, September 27,1984.(Map number 8) Right channel Discharge ~23,600 cubic feeT per second C7 f j~i Discharge =16,200 cubic feet per second Left channel I I I I I I I I I I J t f 5 I I I I ~j,iii , ,I100 t-~W W ::>95ll.-t- ~« Cl z >- Q a:90 t-o:( <::a: >t- w to 85...J a:w « 800 900 1000 1100 2700 2800 2900 3000 3500 3600 3700 3800 3900 4000 4100 DISTANCE FROM LEFT BANK IN FEET 700500600400300100200o iI-I I I r I I I I I I I ~I r I I ),T '1 ,I I 1 -- ,l- I-•Measurement <.10 l- I- )~I - f: l- I- l- I- If--~: I-- t- - I-- l-I,''--.J I I I I II ...T,,I J ,I.-I I N I I,I II.------ Figure 18a.--Cross section and distribution of bedload discharge,Susitna River below Chulitna River near Talkeetna,June 12)1984 (Map numbers 9 and 10) 100 1000 5000 80 I I I I 1 I I I I 1 I I,~I I I I 55 I I , I I , 10,000 - .. . >-« Cl 0::w Cl. v; Z 0 W t- O'~ w· "a:« :I:uv; a 0« 0 ...Jaw tIl Figure 18b.--Cross section and distribution of bedload discharge,Susitna River below Chulitna River near Talkeetna,August 27,1984, (Map numbers 9 and 10) I I I I I I -: - enl <10 -- - - -=--- - - I - - : - : - - ( I "I II I m Right channel Discharge =29.000 cubic feel per second i ll L7 Ii 1"(I I III DISTANCE FROM L.EFT BANK IN FEET ? 500 600 700 800 900 1000 1100 2700 2800 2900 3000 3500 3600 3700 3800 3900 4000 4100100200300400 Discharge =23,000 cubic feeT per second Left channel o I I I I I I I I I I I I '>I I I I 5~I I I I ,I , ~I I I I j~I I I I I I I I I I I --- - ~l- I- l- I- l- I- I- ~ - I I r I I T _T-J I //I .-I I 1000 10 w (,:) a:«:c ~o o 100«g owco >«o a::w 0. Vl 2o I- Z 100 l-iww:J 95 ~t- ~« 0 2 >-9000::- «I-a:«I-> -w co 85 .J a:w ~ 80 10.000 w........ Discharge ~12,600 cubic feet per second•Measurement <10Discharge=2.700 cubic f'1et per second>-<ioII:ill"- Vl Zo I- Z t;;""i 100 r----r---,---~~~-rl---r----r---,---------r----4f ;--,------r--,..-------r----r-----,w :::>u..I-~g 95z>-o II:f=~~'::90wco....III:w <{ 10 ----'-----~ff-L1 __LI .'__--11_---11-7$r-....I-----il~~~~---LLLL.L~------J o 200 600 700 800 900 1000 3600 3700 3800 3900 4000 4100 w· t9 100 II: <i I U Vl o o <io ....Io W tIl DISTANCE FROM LEFT BANK IN FEET Figurl:IBc.--Cross section and distribution of bedload discharge,Susitna River below Chulitna River near Talkeetna,September 26,1984. (Map numbers 9 and 10) 38 110 i I I Ir---w :2 w ::J u..r-- z <l:_ 0 Z >-o a: -<l: f-a: <l:f-> -w ell ....I a: w « :::~-_/ ~- Discharge =4,560 cubic feel per second - - 95 I I I I 200,,I Figure 19a.--Cross section and distribution of bedload discharge, Talkeetna River near Talkeetna,May 18,1984. (Map number 11) DISTANCE FROM LEFT BANK IN FEET 400300 •Measurement <:10 200100 101 • 1 1 I 1 1 1 • 1 ••••• o >- <l:o ~100 0- <J') Zor-- z w \.J ([ <l: J: U '"o o <l:o ....Iow <:Il 39 100 -I I I --- -•Measurement (,10 - -- -- -- ~- -- r--- ~- I-- I-- .-- I-- -- -- -- -I 1 I-10 Discharge =23,400 cubic teel pcr second 100 1101--------------------------,115.---------.----------,-------r--------,95 L ...L..-L -.l ---.J1000I-::EUJ::::lWI-u.«z ClZ>-Q a::I-««a::>I-w I1l-'a::W « >-« Cl (( UJ Q. '"Z 0 I- Z "w· (:J ((« :I:,U "C/l Cl Cl« 0 ...J Cl ill I1l o 100 200 300 400 DiSTANCE FROM LEFT BANK IN FEET Figure 19b.--Cross section and distribution of bedload discharge, Talkeetna River near Talkeetna,August 26,1984. (Map number 11) 40 I-~110 I I I I W :::l W l- Ll..<{ ;~'05~-~~/7<tl-___ > -~:100 - W <t Discharge =2,900 cubic feel per second w·95 I I I I "a::>-30~<{ ~~20IT.Measurement <10 o W0-o <I> <{Zo0 ...J I-~2 10 co -a 100 200 300 400 o 1ST ANCE FROM LEFT BANK IN FEET Figure 19c.--Cross section and distribution of bedload discharge, Talkeetna River near Talkeetna,September 26,1984. (Map number 11) 41 f-~ww :;I.U-f-~<{az>-0 II:f-«<{II:>f-w III..J ccw~ >-« Q CC W 0.- Vl Zo I- Z 11010510095 90 1000 I- i- Discharge =24,600 cubic feet per second •Measurement <.10 600 650500400300200100 w l? II:«100:ru Vl o a <{o -'aw III 10 _--''--L_.I-I.---'----JL.----'....---J---'-....L--l._..L--L-..L-L---L._L-.-4IIIt--.--tIHa_14---t._----l.---..I o DISTANCE FROM LEFT 8ANK IN FEET Figure 20a.--Cross section and distribution of bedload discharge,Susitna River at Sunshine,May 16,1984.(Map number 12) 1000900800700600 Discharge =99,700 cubic feet per second 500400 DISTANCE FROM LEFT BANK IN FEET 300200100 Figure 20b.--Cross section and distribution of bedload discharge,Susitna River at Sunsbine,August 25,1984. (Map number 12) ~I I I I I ~---I I =- l-•Measurement .(10 -I-- -.... -- - ~-=f::- I- - ----- -- -- I I I I I _ - I I I I 95 10 a 100 115 i I I I i I I Iii 110 90 1000 >-~ Cl 0::w <>. '"2 0 l- ~ w· C>1000:« J:u <J) a a ~ 0 -'awco f-~ W::) Wl- u..~ 2 a ~>­o IX:-<t:f-0::«l-> -wOO..JCCw~ I-i~:>LL.I-Z ;3Z>-Q a:I-;i~t::W aJ...J a:W ~110 ~----~------,-------...-------~----~------1051--~95 Discharge =17,800 cu bic feet per seco nd90'-..........--L.--J--..l-.-L._-__---.J 1000 >-« Q a:w 0.. <I) Z 0 I- Z w· l:l 100a:« I U Ul Q Q« 0 ...J 0 W aJ 10 =1 1 T T 1 -----•Measuremenl <10 ----- -- -- f----=~-I-------... I-- -- .-.-.-.-1 1 I 1--.-_1------ ----o 100 200 300 400 500 600 DISTANCE FROM LEFT BANK IN FEET Figure 20c.-·Cross section and distribution of bedload discharge,Susitna River at Sunshine,September 28,1984.(Map number 12) 44 1200 130010001100900800700600500400300 Oischerge =24,900 cubic feet per second 200100 1 I I I I I I I I I I I I I ---------- -- f-- f-- f-- I--- I--I-- I-- I-- I-- I-- f-- f-- 110 I I 1 I I 1 1 1 I 1 I 1 I I 100 951 1 I I 1 1 1 I I I I I I 1 2000 1000 10 o w Cla: <{ :I: ~100 Cl o <{o ..J Cl W CD I--LU ~w :::l U.I- Z <{_Cl Z >-o (( -<{ I-CC <{I-> -w CD ..J (( W <{ >-« Cl a:w Cl.- en Zo I- Z DISTANCE FROM LEFT BANK IN FEET Figure 21a.--Cross section and distribution of bedload discharge,Yentna River near Susitna Station,May 14,1984.(Map number 13) 45 115 ,-----,-----,-----r----,----,---..,----,----r----,---,..---,..---,.------,I-~w ~W l-lL «Z 0Z>-o ~I-a::<!t>Il:l~a:W <!110 Discharge =46.000 cubic feel per second 1100 1200 13001000900800700600500400300200100 I I I I I I I I I I I I•Measurement <10 t:--=f-- f-- f-- >-- f-- >-- I-- >---f--f--I-- f-- I-- f-- f-- I-- --.L.-...L.-..I.---------10 o 1000 95 '-__-'--__-'--__..I-__..I-__..L...__..L...__-'-__-L-__-'--__----'--__---'-__----'-I2000 >-<! 0 a: W 0- '"Z 0 t- ~ w· t? 0:« J: (J 100~ 0 0 <! 0 ...J 0 W Il:l DiSTANCE FROM LEFT BANK IN FEET Figure 21 b.·-Cross section and distribution of bedload discharge,Yentna River near Susitna Station,July 17.1984.(Map number 13) 46 110 iii iii I ii'I I f 1200 130011001000900800700600500400300200100 I I I I I I I I I I 1 I 1-- I----------- -- f--- f-- I--- I--- I--- I--- f---- -- -- -I - 95 I I I I I I I I I I I I I • 2000 Discharge =20,400 cubic feet per second 1000 w CJa:« J:u ~100 a a«a ....Ia Wco 10 o >-«a ([ w 0- W 2a I- 2 I-:2w:> W l- LL « 2 a ~>-a a::- «I-a::«I-> -w co ....I 0: w « DISTANCE FROM LEFT BANK IN FEET Figure 21c.--Cross section and distribu tion of bedload discharge,Yentna River near Susitna Station,September 19,1984.(Map number 13) 47 115110.....~w ~wu......105«~0Z~1000([«.....a:95«.....>w III 90...J 0::w «Discharge;60,100 cubic feet per second8580 1000 1200SOD600400200 0 I I I I I01--•Measurement (1O -- -------- -- I-- I-- I-- f-- ~------- -- -- -- f-- -- loL_T --_..-----~ 2000 1000 300400 10 o w· (:J 0:« J: U II) o o«o ...J ~100en )- «o OCwc. en Zo..... z DiSTANCE FROM LEFT BANK IN FEET Figure 22a.--Cross section and distribution of bedload discharge,Susitna River at Susitna Station,May 17,1984. (Map number 14) 48 1800 20001600140012001000800600400200 I I I I I I I I I I-- •Measurement <10 ~- f-- f-- '-- f-- f-- I-- '--- f-- I--- f--I-- f-- f-- I-- I-- I-- I--- ...1..--I I I10 o 75 1 I I I I I I [ I I I 3000 1000 >-<lo (( l.U 0- Ql Zo 1- Z w· l:J (( <! J: U Ql o o 100<l :3o l.U lXl 120 115 1-::l:110 w ::> W I-105u..<l ~0 z >-100o(( -<!95I-(( <!I-> -w co 90...J a: w 5 85 1 \ / Discharge ~85,3000 cubic feet per second 80., DISTANCE FROM LEFT BANK IN FEET Figure 22b.--Cross section and distribution of bedload discharge,Susitna River at Susitna Station,August 15,1984.(Map number 14) 49 115f-~LU ::J 110LUU-f-«z Q 105-z ~Q 0::«100f-0::«t:95 DIscharge ~57,500 cubic feel per second>LU lD...J a:w «90 -I I I I 1 I ------------- -- -------- -- -.- -- -- -- 1000~«0 0::w c.. V> Z 0 f- ~ ui (,?1000::« :I:u V) a a« 0 ...J 0 LU lD 10 o 200 400 600 800 1000 1200 1400 DISTANCE FROM LEFT BANK IN FEET Figure 22c.-·Cross section and distribution of bedload discharge,Susitna River at Susitna Station,September 20,1984. (Map number 14) 50 o • • Qgravel =9.46 x )0,21 Q4.90 r 2 =0.67 •• o Qsand =1.16 x 1O-8 Q2.38 r 2 =0.82 ~ 0 'o§- •1982 J E ••1983 0 1984 /• Q Stream discharge I IQsandSanddischargel ••Qgravel Gravel discharge J I I I I I I t I I I I I I I 1000 10,000 100,000 1000 10,000 100,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND 100 1000 2000.I I ,I I I I I I I I I I I I >-« 0 0: W Cl.. (I) Z 0 f- 2 w ~ 0:« I u, U >--" 'Jl 0 0« 0 --.J 0 llJ CO Figure 23.--Bedload-transport curves of sand and gravel for Susitna River near Talkeetna,May to September,1982-84. (Map number 6) I ~ / I• Qgravel =7.79 x 10-1002.97 (Average line) Ogravel =1.48 x 10-9 0 2 .97 r 2 =0.59 \•(0 ..:.17 ,500 ft3 Is) /•I I ') Osand'"1.90 x 10-3 01.28 (0 >30,000 ft 3 /s) Osand =1.96 x 10-2 0 1.28 "\/ r 2 =0.45 •I. I .. (Q <.17,500 ft 3/s)•~/ .-/I..i'!. / 0 .. /...~.//..... ;1 0/@bO ;0 /1 Osand'=1.08 x 10,2 Q 1.28 (Average line) •1982 ..1983 o 1984 Q Stream discharge Osand Sand discharge Ogravel Gravel discharge WATER DISCHARGE,IN CUBIC FEET PER SECOND Figme 24.--Bedload transport curves of sand and gravel for Chulitna River below canyon near Talkeetna,May to September,1982-84.(Map number 8) 100 I I I I I J I I I I I I I !I I I I I 1000 .----.--- 1000 10,000 100,000 I I I i I I I I I r I •I I I I I >-«o a::w Q.. (J) 2o.... :2 w ~a::« I U (J) o o«o ...Jo W a:J V1 N o o / ·AS 0"/IA fA. /Q] / / / o Ogravel =2.16 x 10.601.95 r 2 =0.43 o ..1983 o 1984 o Stream discharge Osand Sand discharge Ogravel Gravel discharge WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 25.--Bedload-transport curves of sand and gravel for Susitna River below Chulitna River near Talkeetna (sum of right and left channels),May to September,1983 and 1984.(Map numbers 9 and 10) 100 !I I I !I I1000-!'~I ,I"'.2-'..! 100,000 i "", , I , ,"ii"I I I >- ~ Q a:w 10,0000- C/l Z 0 I- Z Osand '"1.73 x 1O·2 Q 1.09- w ~/c:> 0:: ~ I ./ () C/l .~Q Q 0 ;3'0V1~ W 0 --I 1000 0 /w al /0 0 o Ogravel =3.61 x 10-17 0 4 .65 r2 =0.72• • .. o .~.../~ o • 1982 1983 1984 Stream discharge Sand discharge Gravel discharge •A o Q Osand Ogravel ../ ...o·/ o •./ ~~ GJ I.""0 I. f. /Osand =9.66 x 10,601.93 ,; 5' I· / 10 1.01 I!I I I I I I I I'...l I I I ! !I 1000 10,000 100,000 1000 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 26.--Bedload-transport curves of sand and gravel for Talkeetna River near Talkeetna,May to September,1982-84. (Map number 11)Transport curve of bedload sand was estimated by visual fit of a straight line to the data. 1000 4000 iii I i I Iii I 'I Iii iii i >-« 0 a:::w Q.. VJ Z 0 l- Z- w' <.:J 100a:::«::r: () VJ 0 0 V1 « .p-O oJ 0 Wco 1,000,000 o ... .. ••te /..../....r._£J Ogravel eo 1.68 x 10,501.67 o i)" ....~0 lilt ~IJ.01 : / / / ... •• o ,...... CI •.-ff o --er8 ~~a"nd 0 13.7 0°436 .--/••0 .... ...0 • •1982 ....1983 o 1984 Q Stream discharge Qsand Sand discharge Ogravel Gravel discharge 100 I I J I I I I I I I I I I I I I I I I I 0 10,000 100,000 1,000,000 10,000 100,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 27.--Bedload-transport curves of sand and gravel for Susitna River at Sunshine,May to September,1982-84, (Map number 12) 1000 10,000 100,0001 iii Iii I I I I I I I I I , I i >-«o a: wc... (/) Zo l- Z wo 0:« I <..> (/) o o«o ...Jo Wco V> V1 o / / 0/ / 0 / / o o / Qgravel =1.68 x 10-5 Q 1.67 .-/ / c:P o / o o / Osand =13.70°.436 1984 Stream discharge Sand discharge Gravel d'lscharge o o Osand Qgravel WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 28.--Bedload discharge of sand and gravel versus water discharge for Yentna River near Susitna Station,May to September 1984.(Map number 13)Dashed lines correspond to transport curves for Susitna River at Sunshine, May to September,1982-84.(Map number 12) 100,000 i I I I I I I Iii I I I I I I I I I >- <l:a a:10,000LIJa.. (f) Z 0 I- 2 L1J' ~a: <l::r: () (f) 0 0 <l:Lr1 0 1000 0"> ...Ja LIJco / /0 cP / / / / / / 10,000 Qgravel =1.68 x 10-5 Q 1.67 10,000 o 1984 Q Stream discharge Qsand Sand discharge Qgravel Gravel discharge WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 29.--Bedload discharge of sand and gravel versus water discharge for Susitna River at Susitna Station,May to September 1984.(Map number 14)Dashed lines correspond to transport curves for Susitna River at Sunshine, May to September,1982-84.,(Map number 12) 100 I !I I I I I I I I I I I I I I I I I 1000 100,000 i I I I I , I I 1 I I I I I j ill I >-« Cl a:: 10,000w Q..C 0(J) Z 0t-- Z ~~ w /' <.::J ---a::---0« -----ru I Qsand :13.7 QO.436(f) 0 0« 0 1000.-J 0 W III 100,00010,000 •1982 \A 1983 (May·Sept.)o 1984X1982-84 (Oct.-April)o Strea m dischargeOsBedloaddischarger1000«a a:wa... (/J 2o I- 2 w' ~ex: <l: Io (/J o o c( o ....J o W CQ 100 10 1.0 x 0B =5,30 x 10,902 .48r2-0,78 Os =2.11 x 10.1002.75 1,000,000 O.1 l---...L----l--L...L..L-L.l..J-I-.------,;K.--I-.-L.L.L.LJLJ...L_---.l..-----l.----l.-LJ.ll.LL.-_...L--...L--L....LLJ...l..LJ 100 1000 10,000 100,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 30.--Relation between bedload discharge and water discharge for Susitna River near Talkeetna,1982-84.(Map number 6) 100,000 ; / / / / / /""'-Os =8.66 x 10,1303.72 / /X; / >-«o a:wa.. (J):zo I- :z w <-'a:«:r: ~ o o« 9owco 10,000 1000 100 10 1.0 •1982 \ •1983 (May-Sept.) o 1984 X 1982-84 (Oct.-April)°Stream discharge Os Bedload discharge 0B =1.46 x 10,502 .04 (0 <30,000 ft 3/s) e /..~~/•••e/X:/6s =1.44 x 10,802 .51 oo /0 ~(Q >30,000 ft 3 /s) -/ 1,000,000100,00010,0001000 0.',I J I I I I I vro.I I I I I I I II J100 ''"111''I 1111111 WATER DISCHARGE,IN CUSIC FEET PER SECOND Figure 31.--Relation between bedload discharge and water discharge for Chulitna River below canyon near Talkeetna,1982-84.(Map number 8) 59 100,000 ..1983 101984 (M ay ·Sept.)X 1982·84 (Oct.-April}°Stream discharge 010,000 °B Bedload discharge ~O~0 / 00B=6.82 x 10-4 01.47 /0>-1000 /A<r0 c:: LlJ /0- (I)/z 0 /~ z Os ~2.38 x 10,401.51 LlJ /'"100 c::I« Iu V>/0 0« 0 ..J 0 LlJ 10aJ 1.0 1000 100,000 1,000,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 32.--Relation between bedload discharge and water discharge for Susitna River below Chulitna River near Talkeetna (sum of right and left channels),1983 and 1984.(Map numbers 9 and 10) 60 100,000 t=I I 1 I I i I I i I til Iii II Iii i I I Iii I I Iii I iii •1982} ..1983 (May·Sept.) o 1984 X 1982·84 (Oct.·April) Q Stream discharge QS Bedload discharge 10,000 >-1000 <1:a a: wc.. (I) Z 0 I--- Z w <.:J 100 a: <1: ::I: U {/) a 0 <1: 0 ..J 0 LU 10co ./ ...~o .~.,.~•r Q S =2.62 x 10.7 Q2.38 "ITJ/_ I ~qr ~x / / / I/0B 0 1.44 ,10-8 0 264 1.0 / xl / 1,000,000100,00010,0001000 0.\1 00 IIIPSJIIII I I IIIIIII I 11111111 I IIIIIII1 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 33.--Relation between bedload discharge and water discharge for Talkeetna River near Talkeetna,1982-84.(Map number 11) 61 100,000 •:?4.0B =7.52 x 1O.200.9BO •~0r!.~~./ / / :/ / /Os =2.71 xlO·2 °L05 •1982)•1983 (May-Sept.)o 1984X1982·84 (Oct.-April)Q Stream dischargeOsBedloaddischarge 100 100010,000 w' <;la:: <:( I U Ul o o -::r:.o ....Jow CO >-<:(o 0: UJ ll. Ul 2o I- Z LO 1,000,000100010,000 100,000 WATER DISCHARGE,IN CUSIC FEET PER SECOND O.1 '--_..L.--'--'--'-L-L.L..L.l-_--'_-'---'---'-'-''-'--L-'--_-'----'----'--'--'-'-.L..L.L__-'---'--'--'-L....l.-L-'-' 100 Figure 34.--Relation between bedload discharge and water discharge for Susitna River at Sunshine,1982-84.(Map number 12) 62 100,000 10,000 o 1984 (May-Sept.) o Stream discharge 0B Bedload discharge o o OJ o / / / /Os =7.52 x 10-2 0 0 .980 >-<l:o a:w ll.. (I) Zo ~ z 1000 w' l.::> II:« I U U) o o«o ...Jo W I:D 100 10 1.0 1,000,000100,00010,0001000 0.1 I I I I I I I III I I J I I 1 III J I I I I I III I I I I I I III 100 WATER DISCHARGE,IN CUBIC FEET PER SECOND Figure 35.--Bedload discharge versus water discharge for Yentna River near Susitna Station.May to September 1984.(Map number 13)Dashed line corresponds to transport curve for Susitna River at Sunshine,May to September,1982-84. (Map number 12) 63 100,000 o 1984 (May-Sept.)o Stream dischargeOsBedloaddischarge:>-«a a:: wa.. U) 2:o I- 2: w <.9 0::« Iu U) Q o ex:o -Ia UJco 10,0001000 100 10 10 /Dcfj//r1/Os =7.52 x 10.2 00.09ao 1000 10,000 100,000 WATER DISCHARGE,IN CUBIC FEET PER SECOND 1,000,000 Figure 36.--Bedload discharge versus water discharge for Susitna River at Susitna Station,May to September 1984.(Map number 14)Dashed line corresponds to transport curve for Susitna River at Sunshine,May to September,1982-84. (Map number 12) 64 Table l.--Summary of streamflow and sediment data for selected stations in the Susitna River basin [From Still and Jones,1985 and U.S.Geological Survey,Alaska District files] Drainage Map No.area Period (fig.1)Station number Station name (mi 2 )Data type of record 625000149223500 Portage Creek near Gold Creek --Streamflow 1984 Suspended sediment 1984 Bed sediment 1984 2 624718149393600 Indian Creek near Gold Creek --Streamflow 1984 Suspended sediment 1984 Bed sediment 1984 3 15292000 Susitna River at Gold Creek 6,160 Streamflow 1949-84 Suspended sediment 1952-57,1962,1967,1974-84 Bed sediment 1981 4 ---Susitna River at river mile 128.7 near Sherman Creek --Bed sediment 1984 5 ---Susitna River at river mile 125.6 near Skull Creek --Bed sediment 1984 6 15292100 Susitna River near Talkeetna 6,320 Streamflow 1982-84 Suspended sediment 1982-84 Bed sediment 1982-84 7 15292400 Chulitna River near Talkeetna 2,570 Streamflow 1958-77 ,1979-84 Suspended sediment 1967-72,1980-84 Bed sediment 1981 8 15292410 Chulitna River below canyon 2.580 Streamflow 1982-84 near Talkeetna Suspended sediment 1982-84 Bed sediment 1982-84 9 15292439 aDd Susitna River below Chulitna 8,950 Streamflow 1983-84 10 15292440 River near Talkeetna Suspended sediment 1983-84 Bed sediment 1983-84 11 15292700 Talkeetna River near Talkeetna 2.006 Streamflow 1964-84 Suspended sediment 1966-84 Bed sediment 1981-84 12 15292780 Suaitna River at Sunshine 11 ,100 Streamflow 1981-84 Suspended sediment 1971,1977,1981-84 Bed sediment 1981-84 13 15294345 Yentna River near Susitna Station 6.180 Streamflow 1980-84 Suspended sediment 1981-84 Bed sediment 1984 14 15294350 Susltns River at Susitna Station 19,400 Streamflow 1974-84 Suspended sediment 1975-84 Bed sediment 1984 65 Table 2.--Suspended-sediment data for selected stations in the Susitna River basin,October 1983 to September 1984(Definition of units:fP/s,cubic feet per second;oC,degree Celsius;mg/L,milligrams per liter;ton/d,short ton per day)\latertem-SedtmentWaterpe.ra-c.oncec.-Sed1..ment Suspended eed1mentMapNo.Stacion name-Dace of d19charge ture (ration discharge Percent:finer than size indicated I in mil UmeterH«(11.I)8.nd number collect1011 (ft'/o)("C)(milL)(ton/d)0.002 0.004 0.008 0.016 0.031 0.062 0.125 0.250 0.500 1.000 2.000PortAgeCreeknearGoldCreekMay3059746.4 68(625000 149223500)June:26 1.440 4 16 2S 35 45 50 62 100July2478236.3 7~88 93 99 100Sept.27 39<7 7.4 872IcdianCreeknearGoldCreekMay303392.1 67(624718149393600)June 27 481 2.6 36 55 80 94 100July253883.t 56 74 88 100Sept.27 195 1.6 10 SuattT!8 River .at Gold Creek O~t •3 12.400 14 2.480 /03 (1519<000)Hay 31 12.600 82 2.790 Jl 44 69 99 100 June 21 29.200 476 31,500 H 19 32 40 47 58 68 86 98 100 July 25 29.100 317 24.900 20 24 Z7 J3 45 57 68 85 99 100 Aug.23 18,000 273 13.300 26 33 44 58 70 76 82 92 99 loa Sept.2B 7.140 5.0 17 32B 79 85 92 100 6 Sus 1t IVI R1ve t" near Oct.6 l().600 .5 23 658 32 36 53 98 100 Talkeetna May 16 15,BOO 2.0 46a 19.600 11 14 23 48 61 83 100 (15292100)June 13 25,900 10.5 279 19.500 29 43 66 '16 100 July 9 22.400 12.5 323 19,500 31 37 ~5 74 80 91 100 July 30 30,900 4S8 38,100 17 ZO 29 41 58 82 9B 100 Aug.16 15,200 12.0 120 9.030 44 SO S5 65 75 81 86 93 100 Aug.26 41,000 7.5 132 81,000 10 II 14 2\32 43 58 85 98 99 99 Sept .13 9.380 7.5 V 684 71 76 89 100 Sept.2~8.420 6.0 J 4 318 69 7)85 100 Chulit.na R.lver' below canyQD Oct.5 9.170 1.5 200 4,950 18 21 30 39 48 67 99 100 near May 1B 9.220 4.0 580 14 ,400 8 10 14 22 32 4b 60 14 96 100 T.lkeetu June 11 16.100 8.5 571 24.800 24 Jl 41 51 59 68 16 86 91 100 (15292410)June 14 19,200 6.5 89~46 ••00 23 27 34 47-49 56 69 18 96 99 100 July 11 20.200 8.0 1.010 55.100 30 42 47 S8 6~70 7S 83 94 100 July 31 22,900 6.0 911 56.900 29 35 '-I 49 58 64 71 82 98 100 Aug.11 20.300 6.0 931 51.000 30 35 42 ~2 63 70 17 87 97 100 Aug.28 IB,lOa 4.a S56 27.200 20 22 19 31 46 ~6 64 sa 94 91 100 Sept.14 11,100 4.0 388 11.600 18 23 34 43 53 62 70 83 99 100 Sept-V 7.480 4.0 133 2,690 32 38 44 SO 60 66 69 17 98 100 9 SU15itna River' be:low Chulitna Oct.S t6.000.1.5 166 1,170 30 31 50 98 100 River ~"'Y 18 \8.000a 3.0 646 3).400 10 \4 18 24 38 54 69 83 97 100 (ftght chaDnel)June 12 23.600 10.5 707 45,100 18 25 33 40 46 52 60 7J 97 100 nest"talkeetna July 10 29.200 6.5 1.070 B4.4aO 31 39 49 59 66 72 77 B6 99 100 (15292439)July 30 35.500 6.5 'In 93.500 57 Aug.15 27,000.839 bl.200 26 37 45 ~7 7a 81 87 94 99 100 Aug.27 29.000 5.a 83\65.100 1b 20 24 28 41 55 67 83 97 100 Sept .12 16.700 6.5 209 9.420 21 30 38 45 S3 60 64 75 97 lOa Sept.26 12.600 6.0 159 5.410 11 20 28 37 44 57 93 98 100 10 Sus!tna JU ve.r bel""Oct.5 6.200.1.5 44 737 24 34 75 100 Chulitna River May 17 9.OOOa ~,O 339 8,240 48 65 87 100 llear Talk~etn4 June 12 16,200 11.5 215 9.400 30 40 69 97 lOa (left channel)Ju\y 10 16.000 12.0 3\4 13,600 33 41 56 14 80 90 99 100 (15292440)July 29 19.700 12.0 j09 27.1aO 12 18 30 51 61 87 100 AU8'1S 13,000..270 9.480 40 45 55 71 80 82 88 94 100 Aug.21 22 .000a 6.5 1,070 63.600 12 14 17 27 40 56 63 83 99 100 Sept .12 6,070 8.0 36 ~90 67 74 84 99 100 Sept .16 2.100 7.0 21 IS3 60 64 13 100 •~:H:1mated 66 Table 2.--Suspended-sediment data for selected stations in the Susitna River basin, October 1983 to September 1984'--Continued (Definition of units:ft 3/s,cubic feet per second;oC,degree Celsius;mg/L,milligrams per liter; ton/d,short ton per day) r,.;!ttter tem-Sedimont Wlter per8-conc:en-Sotd1'11'le-nt Suspended sediment Hop No.St6t1oJJ n6tl1e Ooto of diochargo turt trat ion dhc:hyt'8f1 pC!!!rc ent f 1neT them size lnd i cst ed)in mi 1 I1m2tl!rEi (l1g.1)lind number collect1 cn (ft'/0)("C)(m~/L)(,on/d)0.002 0.004 o.ooe 0.016 0.03 I 0.067 0.125 0.250 0.500 1.000 2.000 1\Talkeotno River nl!st Oct.~~,2\0 1.5 41 470 -------- -- 11 T61k~etn"Mar.7 590 --7 II ------ ----11 (15292700)tloy 15 2.440 7.0 79 510 -- -- ------)]B 90 100 tiny 31 4,170 --46 516 ----------15 28 53 100 June 13 11,000 7.5 1.310 42,400 8 9 l?19 31 46 7I 89 99 100 Juno 18 8,370 --290 6.550 10 17 .-27 --41 53 79 98 100 July 26 13,200 --764 21,200 16 19 75 36 50 61 16 92 99 100 July 28 11,200 9.0 396 12,000 ----------4~5)80 99 100 A\lg.16 6,640 11.0 ~)8 7.850 II,19 27 14 44 56 61 ft)98 100 Aug.26 21,700 6.}9I6 56.100 5 7 10 16 24 )6 68 92 99 100 Sopt .26 2,900 --15 III ----------16 ~2 79 LOO 12 SU8Unl!ll River ~f Sun~h1np.:Oct.,28,000 1.0 171 12.900 12 15 --19 --7.9 37 68 99 lOa (I \292 180)Mfty 16 24,600 5.0 440 29.200 10 13 --27 --4)56 72 99 100 /loy 18 34,900 5.\~67 44,000 14 15 --27 --}\63 85 100 June ~4 68.300 --999 184,000 \ 5 17 20 26 34 I.e 70 87 99 100 July 13 52,200 10.5 636 e9,900 71 3J J7 ~7 55 60 66 82 98 100 July 19 1,9,900 --569 76,100 24 31 45 54 65 69 75 87 99 100 July 28 77,700 9.0 960 701,000 27 31 36 '5 55 64 74 87 96 99 100 AU8.\4 45,800 9.5 748 91..\00 22 27 40 )0 57 63 70 8'100 Sept.)\23,300 7.0 166 10.600 23 19 --~~--51 63 76 100 Sept.21 19,600 --284 11,100 \ 3 16 --25 --n , I 6)96 lOa Sept.1S 17,800 5.0 68 4.1,0 2i 17 --34 --46 51 61 100 n 'tt!'1"lt:na klVII!l" ne81'"feb.?3 2.140 0.0 4 24 SUB1tn8 Stotion Apr.5 3,5'0 --J 67 -- -- ----7) (l529434})May 14 24,400 --127 15.000 ------ -- 30 53 85 98 100 June 12 44.300 --363 ').400 20 13 27 )2 42 50 61,91 100 -- J\lly 1)42,900 --684 79,100 18 36 '6 54 6J 68 76 89 99 lao Aug.I'39,400 --192 84.300 '14 19 39 49 57 ~6 7'89 99 100 Sept .19 10,500 --257 14.100 -~~--~----45 .\8 77 91 100 14 Sus t rna RJ Vf'T ot Apr.6 9.090 --185 4,5'0 ---- ------9J Susltna Station Moy 18 61.200 --523 86,400 9 10 -.17 --J \"4 66 90 100 (1529',350 )July 18 97,800 --700 185.000 30 40 50 60 71 80 86 97 100 Aug.15 82.200 --563.125,000 -- --------76 -- -- Sept.20 H.100 --543 80,800 1()15 14 31 38 47 61 90 100 0 EBttm.ated 67 Table 3.--Hydraulic and bedload data for selected stations in the Susitna River basin,October 1983 to September 1984 (Definition of units:ft 3/s,cubic feet per second;ft,foot;ft/s,foot per second;ft/ft,foot per foot;ton/d,short ton per day) Aver-lIater Bed- Water Aver-Age 5ur-load d18-age velo-fact!.d!s-Particle-site distribution of bed sediment Xap No.St8tion name:Date of charge depth lIidth city slope charge Percentage,by weight.finer than site (mM)indicated (f lR.1)and number collection (ft"/s)(ft)(ft)(ft/s)(ft/ft)(ton/d)0.062 0.125 0.25 0.50 1.0 2.0 4.0 8.0 16.0 32.0 64.0 76.0 Portalle Creek MAy 30 597 1.9 108 3.1 0.0057 15 ----0 2 15 29 48 60 74 85 100 near June 26 1,440 2.6 III 4.9 --80 ----0 4 19 32 48 59 64 76 100 Gold Creek July 24 782 2.2 110 3.J --47 ----0 I 5 15 25 36 46 56 88 100 (6250001492 Sept.27 392 1.4 105 2.7 .1 23500) Indian Creek May 30 339 1.7 57 3.5 --4.6 ----0 8 44 62 78 87 100 nest'June 27 481 1,5 18 4.2 --34 ----0 3 15 24 D 44 52 68 100 Gold Cteek July 25 388 2.0 60 3.2 --19 ----0 4 I R 30 45 59 69 73 100 (624718149393600) 6 Sueltna RiveT Oct.6 10,700 3.9 545 5.0 .0014 27 ----0 84 98 99 99 99 100 near feb.17 2,000 --------0 ---------------- Talkeetna tofay 17 17.800 5.0 578 6.1 .0014 296 --0 1 68 97 98 99 100 (15292100)June 13 24.700 5.7 613 7,1 .0014 391 ----0 63 95 96 97 97 99 100 July 9 22,300 5.5 604 6.7 .0014 238 --0 I 67 88 89 90 90 91 94 100 July 30 30.900 6.9 627 7.1 --564 --0 I 61 80 81 83 86 89 90 100 Aug.16 15,200 4.9 559 5.5 .0012 242 --0 I 72 96 97 98 98 98 100 Aug.26 40,900 7.7 636 8.4 .0014 894 --0 2 74 94 95 96 98 99 100 Sept.13 9,340 4.I 551 4.1 .0011 14 ----0 73 9S 95 98 99 100 ~ept.25 8,460 3.6 540 4.3 .0012 29 ----0 77 \00 (j\ 0:>8 Chulitna Oct.5 9.170 5.8 330 4.8 .00044 3,380 --0 I 30 57 61 68 81 90 98 100 River below reb.29 1,420 --------.88 0 1 2 49 73 79 79 84 100 ---- canyon neaT"MAy 18 9.220 5.7 329 4.9 .00074 2,850 --0 I 26 54 63 74 Ill,91 98 100 Talkeetna June II 16,100 7.3 346 6.4 .0010 6,590 --0 I IJ 42 48 55 66 83 94 100 (15292410)June 14 19,400 7.6 354 7.2 .0011 5.170 --0 I 12 25 3\38 47 64 90 100 July 11 20,200 8.3 357 6./1 .00098 3,860 --0 I 12 35 38 42 53 69 86 100 July 31 23.300 8.8 371 7.1 .0012 5,190 __I 0 1 12 26 31 38 54 70 88 100 Au~.\7 19,900 8.~353 6.6 .0012 5,640 --0 I 14 37 41 47 57 73 91 100 Aug.28 17,900 7.9 348 6.5 .00083 4,100 ----0 8 33 37 43 S5 73 92 100 ~ept.14 11,200 6.2 337 5.4 .00057 2.090 --0 I 24 61 71 78 84 92 98 100 Sept.27 7,480 5.5 331 4.I .00039 2,120 ----0 26 74 87 94 97 99 100 '5uo1tna Rivet Oct.5 16,OOOa 4.4 714 5,I --818 ----0 53 77 82 82 83 86 94 100 below Feb.16 1,400a -- ------52 ----0 50 99 100 ---------- Chulitna May 18 18,000a --------3,170 ----a 17 27 34 39 47 6\89 100 Rivet June 12 23.600 4.6 720 7.\--6,980 ----0 9 20 22 25 33 50 76 100 (tight July 10 29,200 5.1 755 7.6 --2,150 -0 I 25 52 57 61 67 75 88 100 channe:l)neaT July 30 35,500 5.7 770 8.1 --5,470 --0 I 20 40 46 55 63 72 85 100 Talkeetna AUI!.IS 27,OOOa --------1,400 ----0 14 27 30 37 48 65 86 100 (15292439)Aug.27 29,000 J.I 1,280 7.1 --12,200 ----0 6 16 19 25 38 58 83 99 100 Sept.12 16,700 3.9 677 6.3 --652 ----0 32 62 64 67 73 80 92 100 Sept.26 12,600 3.7 602 5.7 --2.330 ----0 27 61 63 67 72 80 90 100 LO SUBitna River Oct.5 6,200.3.3 454 4.1 --69 ----0 78 95 96 97 98 98 100 below feb.16 2,000A -- ------0 -------- ---------- Chulltns M8Y 17 9.000..--------272 --0 I 36 36 37 38 39 42 53 100 River June 12 16,200 4.5 620 5.8 --360 --0 1 44 81 83 84 86 89 100 (left channel)July 10 15,000 4.4 580 5.9 --319 --0 I h4 94 94 95 95 97 100 near July 29 19,700 4.9 740 5.4 --790 --0 4 77 94 95 95 96 97 100 Tal keetna AuI':.IS 13,000.-- -- ----196 --0 3 75 85 86 86 87 88 91 100 (15792440)Aug.27 23,000a 4.3 910 5.5 --1,430 --0 5 65 85 86 86 87 88 93 100 ~ept .12 6,070 3.2 sao 3.8 --25 ----0 52 72 73 74 75 80 100 Sept.2€>2,700 2.4 292 3.8 --18 --0 I 46 82 83 85 115 90 100 a Est1mate.d Table 3.--Hydraulic and bedload data for selected stations in the Susitna River basin,October 1983 to September 1984 -Continued (Definition of units:ft 3/s,cubic feet per second;ft,foot;ft/s,foot per second;ft/ft,foot per foot;ton/d,short ton per day) Aver-Water lIed- !,later Aver-aRe sur-load dis-age velo-face dis-Particle-sl ...distribution of bed sediment Hap Nu.Stat ion tlame Date of charge-depth Wldth city .lope charRe Percentage,by weight,fIner than size (mm)indicated (.ig.I)and number collectlon (ft"/s)(ft) (ft)(ft/s)(ft/ft)(ton/d)0.062 0.125 0.25 0.50 1.0 2.0 4.0 8.0 16.0 32.0 64.0 76.0 - II Talkeetna Oet.7 3,070 3.0 323 3.2 --29 --.-0 79 98 100 River near reb.28 590 --------.56 0 1 3 48 97 100 Talkeetna May 18 4,560 3.3 328 4.2 --358 --0 2 33 88 96 99 100 (15292700)May 31 4,080 3.3 324 3.8 --J57 ----0 27 90 95 96 97 97 100 June 13 12,000 5.7 336 6.2 --771 0 1 4 30 76 81 83 85 87 90 100 June 28 8,440 --------712 --0 2 34 87 91 92 94 96 99 100 July 26 13,200 5.9 345 6.5 --762 --0 I 23 66 70 72 75 80 97 100 July 28 11,200 5.5 343 6.0 --688 --0 2 38 81 84 85 87 88 96 100 Aug.16 6,570 4.1 334 4.8 --1,210 --0 I 44 95 98 99 99 100 ---- Aug.24 11 ,200 5.4 338 6.2 --1,920 --0 I 30 88 90 91 93 95 98 100 Aug.26 23,400 7.8 355 8.5 --2,690 --0 I 7 12 15 19 30 54 79 98 100 Sept.26 2,900 2.8 320 3.2 --48 --0 3 58 99 99 100 12 Susltna.Oct.4 28,200 7.9 610 5.9 .0014 1,320 --0 I 40 66 71 72 77 85 96 100 River At reb.23 4,630 ---- ----216 --0 I 30 58 61 64 69 77 93 100 Sunshine Hay 16 24,600 7.5 593 5.5 --t,360 --0 2 46 80 82 83 86 90 96 100 (15292780)June 14 61\,300 9.8 940 7.4 --2,920 0 I 4 45 58 60 61 65 72 84 100 0'Jul Y 13 52,200 8.3 945 6.6 --1,620 --0 1 28 55 58 60 65 71 82 100 \0 July 18 51,200 8.5 802 7.3 --1,340 ----0 33 59 62 65 71 82 94 100 July 28 77,900 10.8 954 7.6 --3,320 --0 I 32 41 43 45 52 65 79 100 Aug.14 45,800 8.8 852 6.1 --3,590 --a 2 33 56 58 60 63 72 88 100 Aug.25 99,700 12.7 960 8.2 --2,580 0 3 II,63 79 80 81 83 88 94 100 Sept.ll 23,300 7.5 580 5.3 --1,190 --0 1 36 56 58 62 71 87 98 100 Sept.21 29,600 8.1 595 6.2 --2,590 --0 2 28 45 47 53 64 78 92 100 Sept.28 17,800 6.9 570 4.5 --1,190 --0 1 59 90 91 92 94 97 100 13 Yentna River May 14 24,900 5.6 1,290 3.4 --11,300 --0 5 65 77 84 90 96 100 $us t tns June 12 43,800 8.5 1,280 4.0 --10,000 --0 5 46 79 84 88 92 96 100 Station July 17 46,000 8.5 1,290 4.2 --6,800 --0 2 43 88 91 94 96 99 100 (1529431,5)Aug.15 40,100 7.8 1,290 4.0 --9,1,80 --0 3 58 88 90 92 94 96 98 100 Sept.19 20,400 5.3 J ,270 3.I --8,220 0 2 48 82 85 90 93 97 100 Ii,SualtnH River May 17 60,100 12.2 975 5.0 8,550 --0 6 80 95 96 97 98 99 100 at Susltna June 13 97,500 10.2 1,860 5.1 --7,460 --0 2 34 85 87 89 92 96 99 100 Station July 18 98,500 --------8,590 --0 3 53 89 92 94 97 99 100 -- (15294350)Aug.15 85,300 8.4 1,870 5.2 --7,370 --0 3 49 71 76 87 91 96 99 100 Sept.20 57,500 8.8 1,520 4.3 --3.250 --0 8 84 90 90 91 92 93 96 100 Table 4.--Bed-material data for selected stations in the Susitna River basin May to September 1984(Sampling point stationing from left bank):Bed material"->p No.Stat10D tlmne n~t'f o(Sampling S"-"'Ple Percent fine.r thaD size indicated,in tlIilllm@-ters(fig.I)and Qumber-c::ollect1oQ point.type 0.062 0.125 0.25 0.50 1.0 2.0 4.0 8.0 16.0 32.0 64.0 128.0 256.0Pot'tag1!Ct'.t:lI!k Sept.!)ne.r JOa .urfaot:e 0 ,57 100GoldC,nl<sub-sut"0 IB 48 71 10035asurface0 4 34 100sub-8ur 0 11 12 19 34 53 69 81 10060asurfAce042865100sub-sur 0 23 55 86 100ladlaDR1ve.r !!.or 30near SO.!Surface 0 1 13 39 100ColdCreeksub-sur 0 1 2 4 9 24 73 100100aBurf"ce 0 1 2 3 4 8 18 47 93 100sub-sur J 12 35 46 51 60 79 97 98 100ISO.Burface 0 I 1 2 2 3 6 .36 71 100sub--ur 0 2 9 23 28 33 43 57 80 100 Suslttl&Rivl!X'Jut1e 5 Left cham:ael at 110.8urf:IJtl!13 31 68 99 100 river dlilo 170.Burf ace 0 2 6 6 6 6 6 6 10 40 100 128.7 sub-eur 0 I 8 20 21 22 24 U J)47 84 100 neill('230a surface 4 1B 66 99 100 SbC'("a$ID Cr@.@.k 290a surf Ace 0 I 2 2 3 3 3 •6 17 66 100 sub-sur 1 J 7 11 IS 19 26 34 47 60 100 }uddle c-baa.nel 100.surface 0 77 100 150.surface:0 I 2 16 51 100 sub-!3ut'0 I 2 6 7 8 12 25 70 100 200.surface 0 J 3 •"5 6 9 36 100 sub-sur 2 I 16 n 26 32 41 62 79 100 250.,urface:0 J 3 J 3 3 4 5 61 100 ~llb-'5u,["I,13 20 2)28 3J .4 )9 78 100 Right ehannol SOc drl!.dge:d 100b dredged 0 13 100 150b d'edged 0 35 100 200b dredged 20 100 250b dredged 0 24 100 300e dredged J50c dredged Sust tn.a RJ.v~r June 6 1.eft chan.nel at 50.surf ace 0 t J t 1 5 39 100 t"1ver I01le sub-sur I I 1 5 11 27 56 87 100 125.6 Qe-a.r ~OOa surface J 3 J 4 11 24 100 Sla.Jll Cree.k suo-sur 13 15 '.'.I B 2'37 ]]101) ~1.ddle channel 50.dredged 0 ~1 100 100b dredged 0 16 tOo i50a sUTface 0 2 II !OO sub-sur B 10 !J !5 21 31 52 100 :00..!Iurfmce 1 2 2 3 "12 59 100 sub-llUr :1 JI,16 If 17 !9 ,3 34 82 100 Right :-hennel SOb dre~ved I I 00 100b dredged 12 12 100 150e dredged 200.d.redged 0 J 6 38 100 ~SOb dredge.d 0 48 100 )25a .surface J J 2 6 23 100 sub-.,ur !I I'IS IB 23 29 50 80 '100 )75.surface J 1 5 25 81 100 ::;ub-s,ur 0 a 14 15 If 18 32 54 78 100 100.dre.d'ged 0 !6 100 '50b drl!dg~d.0 II 100 600b dredged 0 I 6 100 Su..itD«Rlw:r llay 11 near Talk.em.o.surf ace 0 J 13 31 100 (5292100)s.ub-sur 0 J 0 11 12 13 20 29 44 52 100 125b dredgltd 0 1 1 12 100 225b dredgl!!d 0 1 3 8 )9 100 325b dredged 0 13 100 42Sb dredged 0 \'9 100 525b dredged {;.~v 560.surface 0 )!5 57 !OO sub-sur 14 1:18 22 29 42 60 '8 100 Chul1 t ....RJ.....llay 18 bill!!1 ow canyon 30e dredgod near ralke..tn.80.dril!:dged 2 18 26 n 47 69 86 100 (1529<410)120.dredged 36 68 iO 75 81 90 96 100 200.dredged I 14 20 2S 3-47 59 83 \00 280~dredged 0 I 5 35 \00 70 Table 4.--Bed-material data for selected stations in the Susitna River basin May to September 1984 --Continued (Sampling point stationing from left bank) Bed material ~'Hl :Sc..Sr.4tion nut O.te of SupUog Sample Percent finer than size indicated.in aillimeteT6 (:Ill·I)and I1Ul11ber c:ollectiot'l poiot type 0.062 0.125 0.25 0.50 1.0 2.0 ~.0 8.0 16.0 32.0 64.0 128.0 256.0 9 SUl!iilttl..River MAy 17 bel"",3760.d dredged ---0 I )3 4 6 12 29 64 100 Chulitna River 3860.d dredged ---- ----0 I 2 15 15 100 (right nhannel)3960.d dred~ed -.-0 2 )9 29 48 72 87 100 - neaT Talkeetnlt 4060.d dredged ------- -------0 25 100 (52924)9) 10 Sus1tna RJver Kay \; belo.l Chulic'Dti 100ad dred~ed -------- - -0 7 8 44 100 Rive!600ad dredlud ---- - ---0 I 4 18 65 :0(\ (left channel)700.d dred~ed .--------0 I 2 10 35 74 100 near TaHu~etna 800ad dredged --- - --------0 6 16 loe (l5292~40\900.d lurfac('C I 2 3 )3 3 4 7 35 100 IJUb-aur I :~21 22 24 29 38 60 88 100 1000.d surfuce ---- -----0 I 5 U 60 10C flub-sur \2 5 16 20 22 27 38 55 75 10: 2750.d 8urface \1 )5 5 5 5 6 10 29 100 sub-sur 2 5 I'62 62 64 68 74 84 97 100 II Talke-etna !'lay 15 'Rtver 30a surt ace -----------0 2 24 100 near Talkeetna SUD-aUT 0 2 5 10 12 16 J9 25 38 65 100 (15292700)Bo.dredged --n I 16 51 53 53 54 54 54 63 100 130.dred@ed --0 I 17 72 78 79 19 79 81 8~100 180.dre.dged --0 I 8 41 47 48 49 51 59 90 100 230.dredged --0 3 37 50 55 56 58 65 10('- 340B aurlacf----------------0 \I 50 100 SUb-SUT 0 I 2 3 4 5 6 B 13 45 100 - 350a surfaCf----0 I I I I 1 2 6 22 100 Bub-sur 3 ~11 16 25 30 35 45 58 84 100 I'SuSltna River K8~16 at SUD6hlne 100b dredged ----- --------0 8 100 (\5292780)200.dredged --0 1 46 87 88 88 89 91 92 100 - 300.dredged ---0 1 2 4 8 15 44 ~I 95 100 400.dredged --0 I 2 3 3 4 5 7 25 49 100 500b dredge~-----------0 2 18 100 675.surf ace --0 2 5 5 5 6 6 9 23 100 - Bub-Bur I 2 2 5 \I 15 18 22 29 40 69 100 725.aurrace I 4 19 94 100 --,-------- Bub-8UT 1 2 11 41 41 44 44 45 47 57 88 100 800.surface 41 76 97 100 IJ ientna River l1>oy 14 'Dli!.ar 100a dredged 0 I 24 80 82 83 87 92 96 100 Susltt\{l Stilt too 200.dredged 0 I II S6 70 76 80 84 90 99 100 (5294345)300.dredged 0 !15 89 89 89 89 91 94 98 100 400.dredged 0 I 15 83 85 85 85 85 86 89 100 500.dredged 0 I 18 79 83 83 84 85 86 94 100 600.dred,:ted 0 I 16 91 95 95 96 98 99 100 700.dredged 0 1 17 97 98 99 99 99 100 -- 800.dredged 0 I 9 82 89 92 95 98 99 100 900.dre.dp:ed --0 4 83 B3 85 87 90 96 100 1000.dredged -.0 4 50 87 93 96 98 100 1100.dredged --0 2 46 56 68 82 95 100 1200.dredged --0 I SO 51 61 79 94 100 14 Sus1 tna R1ver llay 17 at 200.dredged --0 6 89 94 94 95 95 97 100 SUD shine StAtioQ 300.dredged --0 5 58 86 88 91 93 9S 98 100 (15294350)400.dredged --0 4 47 91 93 94 95 98 100 500.dredged --0 5 69 99 99 99 99 100 600.dredged --0 7 93 99 99 99 99 100 700a dredged --0 14 99 100 ------ 800.dredged 0 I 27 93 98 98 98 99 100 900.dredged 0 1 7 32 38 39 44 52 65 90 100 •AepreseQlat.lve aatPl~obtained for particles finer than 128 _ b Frv particleI'obt:alned.non-representative 8utple n Streambed too COATee for obtaining aarples d Statlonll\3 from loft bank of Su.1tna R.lver,loft cbannel (15292440) 71 Table 5.-Water discharge and estimated total sediment loads at selected stations in the Susitna River basin October 1983 to September 1984 --Continued ' (Definition of units: mi~ square-~le; acre-ft, acre-foot; tons, short tons) Drainage Water M.1p No. area discharge Sus~ended sediment (tons) Bedload (tons) Total sediment (llg. 1) Station name and number (mi 2 ) Period (acre-ft) Silt-clay Sand Total Sand Gravel Total (tons) 12 Susi tna River 11,100 October 1,310,000 290,000 15,000 6,900 21,900 312,000 at Sunshine November 492,000 12,000 6, 700 1,800 8,500 20,500 (15292780) December 342,000 3,100 5,000 1,000 6,000 9,100 January 301,000 2,100 4,500 870 5,370 7,470 February 265,000 1,600 4,000 740 4, 740 6,340 March 276,000 1,600 4,200 770 4,970 6,570 April 271,000 1, 700 4,100 760 4,860 6,560 May 1,590,000 440,000 440,000 880,000 34,000 10,000 44,000 924,000 June 3,530,000 1,700,000 1,400,000 3,100,000 46,000 29,000 75,000 3,180,000 July 3,640,000 2,200,000 1,300,000 3,500,000 35,000 30,000 65,000 3,560,000 August 3,610,000 2,500,000 1,400,000 3. 900,000 58,000 67,000 125,000 4,020,000 September 1,420,000 170,000 190,000 360,000 27.000 19,000 46,000 406,000 October to 3,260,000 312,000 43,500 12,800 56,300 368,000 April May to 13,800,000 7,010,000 4,730,000 11,700,000 200,000 155,000 355,000 12,100,000 September Total 17,000,000 12,100,000 244,000 168,000 411,000 12,500,000 1 J Yentna River 6,180 October 660,000 91,000 near November 324,000 5,600 Susttna Station December 220,000 1,400 (15294345) January 162,000 400 February 133,000 230 March 140,000 250 April 342,000 16,000 May 1,900,000 540,000 610,000 1,150,000 June 2,980,000 1, 700,000 1,300,000 3,000,000 July 3,230,000 1,900,000 1,400,000 3, 300,000 August 3,280,000 2,200,000 1,500,000 3,700,000 September 1,130, 000 160,000 270,000 430,000 October to 1,980,000 115,000 10;000c 10,000c 20,000 135,000 Aprfl Hay to 12,500,000 6,500,000 5,080,000 11,600,000 1,000 ,OOOc 200,000c 1,200,000 12,800,000 September Total 14,500,000 11,700,000 1,000,000 210,000 1,220,000 12,900,000 14 :=:~tR~ tn~·. R:Jver 19,400 October 2,420,000 410,000 at November 1,130,000 42,000 ::!Jsitna Station December 706,000 11,000 (!5294350) January 457,000 3,000 February 386,000 2,200 March 400,000 2,000 April 775,000 20,000 May 3, 720,000 1,000,000 I, 200,000 2,200,000 June 6,370,000 3, 700,000 2,600,000 6,300,000 July 6, 720,000 3,900,000 2, 700,000 6,600,000 August 6,820,000 4,200,000 2,800,000 7,000,000 September 3,040,000 620,000 940,000 1, 560,000 October to 6,270,000 490,000 6,000c 700c 6, 700 497,000 April May to 26,700,000 13,400,000 10,200,000 23,700,000 1,000,000c 100,000c 1,100,000 24,800,000 Sept'7-mber Total 32.900,000 24,200,000 1,000,000 100,000 1,110,000 25,300,000 ------··· Estimated from average bedload measurements. GPO 791-317/60006 73