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HomeMy WebLinkAboutAPA890CROSS-SECTION, VELOCITY, AND BEDLOAD DATA AT TWO EROSION SITES ON THE TANANA RIVER NEARF~RBANKS,ALASKA,1979 Prepared by the United States Department of the Interior Geological Survey In cooperation with Alaska District and Cold Regions Research and Engineering Laboratory, U. S. Army Corps of Engineers UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY CROSS-SECTION, VELOCITY, AND BEDLOAD DATA AT TWO EROSION SITES ON THE TANANA RIVER NEAR FAIRBANKS, ALASKA, 1979 by Robert L. Burrows Open-File Report 80-699 Prepared in cooperation with Alaska District and Cold Regions Research and Engineering Laboratory, U.S. Army Corps of Engineers Anchorage, Alaska 1980 i UNITED STATES DEPARTr1ENT OF THE INTERIOR CECIL D. ANDRUS, Secretary GEOLOGICAL SURVEY H. William Menard, Director For additional information write to: U.S. Geological Survey Water Resources Division 733 W. 4th Ave., Suite 400 Anchorage, Alaska 99501 i i CONTENTS Page Abstract.............................................................. 1 Introduction.......................................................... 2 Data collection....................................................... 2 Data far a i rpo rt s i te . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Data for Corps of Engineers dike site................................. 22 References cited...................................................... 32 1. 2. 3. 4. 5a-f. 6. 7. 8. 9a-b. 1 Oa-d. ILLUSTRATIONS Map showing location of Tanana River, data-collection sites, gaging station, and Fairbanks •••••••••••..••••••••••••••••••••. Hydrograph of mean daily discharge for Tanana River at Fair- banks ••..••••••••..•••....•.•••••••••••••••.•.••••••••••••.••.• Aerial photograph of data-collection site near airport at Fair- banks •••••.•••••.•••••••••••••••••••••••••••••••••••••••••••••. Plan sketch showing location of ice revetment and edge of bank at airport site as surveyed by CRREL on indicated dates ••••••••••• Cross sections at airport site, t1ay 17, 1979 •.•••••••••••••••••• Cross section 6+00, airport site before and after revetment ••••• Cross section 8+00, airport site, before and after revetment ••.• Cross section 10+00, airport site, before and after revetment ••• Velocity distribution, near right bank, at cross section 6+00, airport site .................................................. . Velocity distribution, near right bank, at cross section 8+00, airport site .................................................. . lla-d. Velocity distribution, near right bank, at cross section 10+00, 12. 13. 14. 15. 16. 17. airport site ................................................. . Cross section 8+00 showing graph of velocity distribution and bedload-transport rates, airport site, June 25, 1979. Top: velocity distribution at 80 percent of depth. Bottom: bedload-transport rates ....................................... . Cross section 8+00 showing graph of velocity distribution and bedload-transport rates, airport site, August 16, 1979. Top: velocity distribution at 80 percent of depth. Bottom: bedload-transport rates ....................................... . Composite particle-size distribution of bedload, June 25, 1979, section 8+00, airport site ••••••••••••.••••••••••••••.••••.•••• Composite particle-size distribution of bedload, August 16, 1979, section 8+00, airport site ••••••••••••••••••••.•••••••••• Aerial photograph of data collection site at dike near North Po 1 e •••••••••••••••••••••••••••••••••••••••••••••••••• • ••• • • • • • Plan sketch showing location of edge of bank at dike site as surveyed by CRREL •••••••••••••••••••••••••••••••••••••••••••••• iii 3 5 6 7 9-11 12 13 14 15 16-17 18-19 20 21 23 24 25 26 ILLUSTRATIONS--Continued Page 18a-b. Cross sections 4+50 and 7+00 at dike site...................... 27 l9a-b. Velocity distribution near right bank, at cross section 4+50, d i ke s i te . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 20a-b. Velocity distribution near right bank, at cross section 7+00, d i ke s i te ........... ~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 21. 22. Cross section 4+50 showing graph of velocity distribution and bedload-transport rates, at dike site, August 17, 1979. Top: velocity distribution at 80 percent of depth. Bottom: bedload-transport rates ...................................... . Composite particle-size distribution of bedload, August 17, 1979, section 4+50, dike site ••.•••..••••.••••••••.•••••.••.•• FACTORS FOR CONVERSION OF UNITS 30 31 The following factors may be used to convert the commonly used American units here- in to the International System of Units (SI). Multiply American units inch (in.) foot ( ft) mi 1 e (mi) pound (lb) ton, short cubic foot per second (ft 3 /s) pound per foot (lb/ft) ~ 25.4 0.3048 1. 609 0.4536 0.9072 0.02832 1.488 iv To obtain SI units mi 11 imeter (mm) meter (m) kilometer (km) kilogram (kg) metric ton (tonne) cubic meter per second (m 3 /s) kilogram per meter (kg/m) CROSS-SECTION, VELOCITY, AND BEDLOAD DATA AT TWO EROSION SITES ON THE TANANA RIVER NEAR FAIRBANKS, ALASKA, 1979 By Robert L. Burrows ABSTRACT In an effort to relate river processes to vertical and lateral erosion at two sites on the Tanana River in the vicinity of Fairbanks, measurements of depth, velocity, and bedload-transport rates were made at several sections at each site. To facilitate comparison of the river processes and ongoing erosion, compila- tion and graphic presentation of the velocity distributions and bedload-transport rates are presented in conjunction with cross-section configuration immediately adjacent to the area of erosion. Dry sieve analyses of the bedload samples give particle-size distribution. Approximately 85-95 percent of the material in transport at both sites was in the s·and range ( > 0. 062 mi 11 imeter < 2. 0 mi 11 imeters). 1 INTRODUCTION To facilitate the monitoring of the fluvial processes related to erosion on the Tanana River, the U.S. Army Corps of Engineers Cold Regions Research and Engi- neering Laboratory (CRREL) requested that the U.S. Geological Survey collect and compile selected river-hydraulic and bedload-transport data at two sites during the period of principal runoff in 1979. One of the sites is near the Fairbanks International Airport on the right,or north bank, and the other site is at a dike near North Pole on the right,or north bank (fig. 1). The airport location is the site of an experimental ice revetment constructed by CRREL in January-March 1979, which failed during spring breakup. This site has been subject to rapid erosion which threatens the airport railroad spur, and major slumping of the bank occurred in May 1979. The State of Alaska Department of Transportation (Alaska DOT) constructed a rock revetment at this site from July 16 to August 29, 1979. The erosion site near North Pole is at a dike constructed by the Corps of Engineers in 1974-75, and is the location of several types of experimental revetment built by the Corps and CRREL. CRREL requested that the Survey measure stream velocities near the bank at several specific sections and collect bedload-transport data at one section. Discharge measurements of only the flow immediately adjacent to the two sites were to be made during high and low flow at the airport and at high flow at the dike. The concern was the erosion of the right bank at both sites. Therefore, mostly partial rather than complete cross sections were measured. Measurements and sam- pling were done only in the main channel. The Corps of Engineers District Office, Anchorage, Alaska, requested that the Survey monitor changes in the channel configuration at several of the CRREL sec- tions along the right bank at the airport site. This report is principally a graphical presentation of the data collected in 1979 at both sites. The text is devoted to the explanation of figures. The pri- mary purpose of this report is to provide CRREL and the Corps of Engineers with information related to the erosion occurring at the two sites. This program was funded by the Corps of Engineers through a cooperative agree- ment with the U.S. Geological Survey. CRREL provided the surveying, maps, and on-site location rna rkers necessary for data collection. Aerial photographs were provided by the Corps of Engineers. All data collection and compilation were performed by Survey personnel. DATA COLLECTION Measurements of depth and velocity and collection of bedload samples were made from a boat. The boat was positioned using sextant readings on a base line for cross-channel stationing and visual reference to range markers on the cross-section ends for on-station positioning. Depths were obtained through the use of either a recording fathometer or sounding with a cable-suspended weight. Generally, the fathometer was used when velocities were not being measured. 2 0 0 EXPLANATION ,J~ \ \ \ \ I \ \ A Data collection site A Gaging station 2 4 \ \ I 6 Miles 4 6 8 Kilometers E3 E+3 E+3 I 0 + Figure 1. --Location of Tanana River, data-collection sites, gaging station, and Fairbanks. 3 lS Velocities were measured with a Price AA current meter using standard Survey methods (Buchanan and Somers, 1969). Point velocities were usually obtained at each of several statfons on the specified cross sections. To define vertical distribution, velocities were determined 1 ft above the streambed, at 20, 40, 60, and 80 percent of depth, and near the surface. The mean for each vertical was computed by averaging all the point velocities in the vertical. Surface velocities were usually measured several tenths of a foot below the water surface; some of these may be slightly in error due to the bobbing motion of the boat at stations in the most turbulent flow. Main channel discharge was determined on June 25, August 16, and October 2 at the airport site, and on August 17 at the dike site near North Pole. Mean daily values of total discharge of the Tanana (not including flow in Salchaket Slough) were obtained from records for the gaging station Tanana River at Fairbanks (station 15485500) for the period of principal runoff (fig. 2). Stream- flow data for this station are available in the annual publications of the Survey entitled 11 Water-Resources Data for Alaska ... Bedload samples were collected using a Helley-Smith bedload sampler (Helley and Smith, 1971). The Survey has not officially adopted the Helley-Smith as standard equipment, and results obtained through its use cannot be certified for accuracy. However, the Survey has recently issued provisional guidelines for use of the Helley-Smith sampler pending further research and testing. The sampler has been used since 1977 on the Tanana River (Burrows, Parks, and Emmett, 1979), and a field determination of the sediment-trapping characteristics of the Hell ey-Smith bedload sampler (Emmett, 1979) indicates that no correction factor need be applied to the bedload data as collected. Bedload samples of 30-second duration were taken at every 50 ft of main chan- nel width. Individual samples were weighed to determine transport rates, in (lb/ft)/s, but composites of samples were used for dry sieve analyses to determine particle-size distribution. Equal weight was given to each sample in computing the average transport rate. All water-surface elevations were referenced to the National Geodetic Vertical Datum of 1929. The water-surface elevation was determined during each visit at section 8+00 at the airport site and section 4+50 at the dike. These single water- surface elevations were used to compute bed elevations at all cross sections measured. DATA FOR AIRPORT SITE AT FAIRBANKS Figure 3 is an aerial photograph of the Tanana River in the vicinity of Fair- banks International Airport. The photograph shows the reach of the river past the airport erosion site, the section of eroding bank, and, in particular, the airport railroad spur. Figure 4 is a sketch showing the stationing along the right bank, the ice revetment in relation to the railroad, and the edge of the bank on two different dates, as surveyed by CRREL. 4 50,000 Cl 20,000 z 0 C) 1'1:1 00 t:l:: 1'1:1 ~ :;...~ 10,000 ....:11'1:1 '""'Pr.. <u Cl,... (.}'1 zi=Q c:t:P l't.lC) ~2:: 1'1:1" 5,000 C!l t:l:: < J:I: C) 00 ,.... Cl 2,000 APRIL A A A "' "' "' .... t;-.... r!. t;-.b .... <D ~ .b < <D ..... ...... $ ...., $ MAY JUNE JULY A "' t;-.... "' '-;! .... 00 ~ ..... 0 ~ .... ! A "' "' t;-.... --<D rb .... -a, oO ..... $ ,.... $ < _, (N) Dlte of data collection at North Pole (A) Dlte of data collection at airport site AUGUST SEPTEMBER OCTOBER Figure 2.--Hydrograph of mean daily discharge for Tanana River at Fairbanks. Corps of Figure 3 . --Data-collection site near airport at Fairbanks. 6 DISTANCE ALONG RIGHT BANK ,IN HUNDREDS OF FEET (2+00 = 200 FEET) 16+00 / / 0 200 400 FEET 1~--~----~'--~-L----~' I I I I 0 40 80 120 METERS Figure 4. --Plan sketch showing location of ice revetment and edge of bank at airport site as surveyed by CRREL on indicated dates. 0 300 Figures 5a-f show the cross sections and partial cross sections along the right bank at the airport site. The cross-channel stationing shown was measured from the right bank ref~rence, which is the railroad spur. Sections are shown in downstream order. In those cases where both soundings and fathometer traces were obtained, both sets of results were plotted. The dif- ferences between these results are due more to the difficulty of repositioning the boat at a given location on the cross section than to inaccuracies in either method of measuring depth. Cross-section data collected at sections 6+00, 8+00, and 10+00 before and after Alaska DOT constructed a rock revetment are shown in figures 6, 7, and 8. This revetment extends from station 1+50 to 15+00. The work was not completed until August 29, but the revetment at section 6+00, 8+00, and 10+00 had been finished when data were collected on August 16. Additional material was placed near section 2+00 on October 2, 1979. In addition to the data presented in these figures, several individual depths along other sections at the airport site were measured. These measurements were made at the request of Alaska DOT during and following construction of the revet- ment. While depths and elevations shown below are accurate, distances from the bank are estimated. All measurements are given in feet. Section August 16 SeQtember 6 October 2 Di st. Depth Elev. Dist. Depth Elev. Dist. Depth El ev. from from from bank bank bank 2+00 75 25 394.1 15+00 50 44 380.5 100 36 384.8 16+00 80 41 383.5 150 39 381.8 Vertical velocity distributions at cross section 6+00 are shown in figures 9a and b, 8+00 in figures lOa-d, and 10+00 in figures lla-d. Velocities are shown at points,and the mean for each vertical is shown above the station. Velocities at 80 percent of the depth and bedload-transport rates across the channel at section 8+00 for June 25 and August 16 are shown in figures 12 and 13. Velocities were taken from measurements made on the two dates. Bedload-transport rates were computed from the weights of samples collected at the points shown. The cross sections in the top of the figures allow comparisons between depth, veloc- ities, and transport rates. The transport rate at station 560 for June 25 may be anomalously high for the corresponding velocity. Neglecting this sample, the average transport rate across the section is 0.079 (lb/ft)/s. Including the sam- ple, the average transport rate is 0.083 (lb/ft)/s. The lower value is shown on figure 12. The average transport rates shown in figures 12 and 13 give loads of 1,690 tons per day and 330 tons per day on June 25 and August 16 respectively. Water discharge measured in this channel was 28,600 ft3js and 38,200 ft 3/s on these two days. 8 425 420 E-< 415 ril ril r:. z 410 .... z· 0 .... E-< < > ril 400 ...:I ril 390 800 700 600 200 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 5a. --Cross section 4+00 at airport site. May 17,1979 ---Fathometer ---Sounding DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 5b. --Cross section 6+00 at airport site. 9 100 0 415 E-< ril ril ~ z ...... :i 0 ...... E-< < > ril ..:I ril 395 390 800 800 May 17, 1979 -Fathometer ___ Sounding 700 600 500 400 300 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 5c.--Cross section 8+00 at airport site. May 17,1979 ---Fathometer ---Sounding 500 400 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 5d. --Cross section 10+00 at airport site. 10 200 100 0 0 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 5e. --Cross section 12+00 at airport site. DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 5f. --Cross section 14+00 at airport site. 11 BEFORE ALASKA DOT REVETMENT 385 700 600 0 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET August 16, 1979 Octobe~~-:;9 7- AFTER REVETMENT DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 6. --Cross section 6+00 , airport site,before and after revetment. 12 425 800 420 -.: .................. ············ ............ ······················· ......... ······~ ·••. ---------J"u";:7:197'9:.7---, E ~ : ·••··•···•··• May17,1979_/ ,' ! I • I I . . . . BEFORE ALASKA DOT REVETMENT 700 600 500 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET August 16, 1979 .... ····· .. ,_ .. .............. .:.:.:, "'":'~ ··~ ... AFTER REVETMENT 700 600 500 400 100 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 7. --Cross section 8+00, airport site, before and after revetment. 13 0 0 700 :i 8 410 ~ > ~ 405 ri:l 400 --------------------, -.... .... _ ........ May 17,1979 ' '-~June 7, 1979 ' ' ' ~ BEFORE ALASKA DOT REVETMENT 400 100 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET August 16, 1979 September 6, 1979 ' \-----------------.:::::;::.:; \ A October 2, 1979 I \I' , ____ .... ' ., ---' --, I ,_ I ', I ' I ' . ..... I" ' i AFTER REVETMENT 0 395~--~--~--------L-------~--------~--------L_ ______ _L ______ __J 700 600 500 400 300 200 100 0 DISTANCE FROM RIGHT BANK REFERENCE, IN FEEr Figure 8. --Cross section 10+00, airport site, before and after revetment. 14 420 V=5.0 v=5.6 V=5.8 V=5.3 V=4.8 V=3.4 6.3 6.5 7.1 7.0 5.3 ··v 4.6 5.3 3. 5.0 6.3 6.2 6.4 1.9 ···; 4.2 6.2 5.4 ~ 5.4 5.6 f:il 4.4 f:il r:. 5.2 2.0 z 5.2 5.6 ...... 5.4 :i 3.6 0 405 5.1 ...... 5.6 ~ < 5.2 :> 4.7 f:il ...:l 400 f:il May 17,1979 V=MEAN VELOCITY VELOCITIES IN FEET PER SECOND 395 280 180 160 140 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 9a.--Velocity distribution,near right bank, at cross section 6+00, airport site. 420 V=6.6 V=6.4 V=7.0 V=5.2 7.1 7.4 415 7.1 7.1 7.4 ~ f:il 7.1 6.5 f:il r:. 8.2 z 410 ...... 6.3 6.8 :i 0 8.1 ...... ~ 5.8 5.8 < :> f:il 5.4 5.4 ...:l f:il V=MEAN VELOCITY VELOCITIES IN FEET PER SECOND 395 280 260 240 220 2 0 180 160 140 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 9b.--Velocity distribution, near right bank, at cross-section 6+00, airport site. 15 420 V=5.7 V=5.8 V=6.4 V=6.8 V=4.8 6.7 7.1 7.8 8.6 i 7.3 E-< 6.7 f;l;1 5.6 6.0 f;l;1 7.0 r:z;. z 7.0 6.8 ...... 6.0 6.2 z 0 410 7.1 ...... E-< 6.0 < 6.5 > 6.3 f;l;1 ...:I f;l;1 5.4 4.6 May 17,1979 V = MEAN VELOCITY VELOCITIES IN FEET PER SECOND 400~----~~--~~----~~--~~----~~--~~----~~--~~ 260 240 220 200 180 160 140 120 100 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure lOa.--Velocity distribution, near right bank, at cross section 8+00, airport site. 425 v=5.1 V=5.4 7.8 9.1 7.8 8.4 7.4 5.4 5.6 5.4 6.3 6.3 E-< f;l;1 4.2 f;l;1 r:z;. z 5.2 ...... 6.1 6.3 5.2 z 3.4 0 ...... 5.2 E-< < 4.0 > 5.2 5.8 4.6 f;l;1 ...:I f;l;1 5.0 4.4 4.0 3.9 3.8 3.4 June 25, 1979 V = MEAN VELOCITY VELOCITIES IN FEET PER SECOND 395 260 240 220 140 100 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure lOb.--Velocity distribution, near right bank, at cross section 8+00, airport site. 16 425 V=6.4 V=6.4 v=6.6 V=6.3 V=6.8 v=6.6 9.5 9.5 9.9 9.7 9,5 7.1 7.8 7.8 6.7 7.8 6.4 415 6.8 7.1 E-< ril 6.3 6.3 ril 6.3 ~ z 6.2 6.1 ..... 410 z· 5.3 0 6.7 ..... 6.1 E-< 4.8 4.8 < :> 4.0 ril ~ 2.2 ril ···; 5.2 400 4.0 395 August 16, 1979 V=MEAN VELOCITY VELOCITIES IN FEET PER SECOND 390: 240 220 200 180 100 80 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure lOc. --Velocity distribution, near right bank, at cross section 8+00, aiiport site. · 420 V=5.8 V=6.5 V=7.1 6.5 7.1 7.8 '·7 3.4 7.1 7.4 7.4 3.3 7.8 E-< 415 8.2 2.5 ril 7.4 2.4 ril 6.8 ~ 7.1 7.4 1.8 z 6.8 7.8 ..... 7.1 z· 410 6.5 7.1 0 4.0 ..... 5.8 7.8 E-< 6.1 < 3.0 :> ril ~ ril 405 400 240 180 120 100 80 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure lOd. --Velocity distribution, near right bank, at cross section 8+00, airport site. 17 420 V=6.2 V=6.0 V=5.8 V=5.3 V=2.3 7.4 7.1 7.4 6.4 E-< 6.5 6.3 6.1 ril 6.2 ril 415 6.1 "" 6.1 z 6.3 5.7 ...... 5.6 0.5 z-6.3 0 410 ..... E-< < 5.8 :> ril 5.0 ..:I ril 405 280 260 240 220 200 180 160 140 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 11a. --Velocity distribution, near right bank, at cross section 10+00, airport site. Figure llb. --Velocity distribution, near right bank, at cross section 10+00, airport site. 18 425 V=6.8 v=6.9 v=6.8 v=6.8 v=6.3 9.1 9.5 9.7 8.4 V = MEAN VELOCITIES VELOCITIES IN FEET PER SECOND 6.8 7.4 8.0 7.3 August 16, 1979 7.4 7.3 E-< 7.1 7.6 ril ril ~ z 7.4 ..... 7.0 6.7 7.1 :i 0 ..... E-< 6.4 < 5.8 &; 6.0 6.1 ...:I 4.4 ril 400 220 200 180 140 80 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure llc. --Velocity distribution, near right bank, at cross section 10+00, airport site. 6.5 7.1 4.8 6.5 5.0 5.4 October 2,1979 ~ V= MEAN VELOCITY VELOCITIES IN FEET PER SEC 400·~ ____ _. ______ ._ ____ ~~----~----~------~----~ 220 200 180 160 140 120 100 80 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure lld. --Velocity distribution, near right bank, at cross section 10+00, airport site. 19 ~ 0.26 0 g 0.24 ) 00 ~ 0.22 p... E-< ~ 0.20 r:.:.. p:: 0.18 ril p... r:3 0.16 z 5 0.14 p... ::::: 0.12 ril E-< 0.10 < p:: f- 1- 'I- 1- f- I 1- I I E-< 0.08 p:: f.:::. _______ 0 ~ 0.06 ~ p:: 0.04 Ej' ~ 0.02 0 ...:I 0 1- 1- 1- Cl 800 ril I I 700 600 I t:-· .... ..... 0 ----- t:-.... ..;o 0 .... 0 0 I. i 500 I I T l "' ..;o ~ 0 ..;o 00 -.... 0 - - .... .... .... -0 - ------~VERAGE RATE.£:_079 -= t:-..;o -0 0 - "" lO 0 0 - 0 0 ~. ~ I 400 300 200 100 0 ~ DISTANCE FROM RIGHT BANK,REFERENCE, IN FEET Figure 12. --Cross section 8+00 showing velocity distribution and bedload-transport rates, airport site, June 25, 1979. Top: velocity distribution at 80 percent of depth. Bottom: bedload-transport rates. 20 8 :I: E-o 6 p., ""' QQ 4 E-oz zo r.:<o 2 Or.:< ~rn ""'~ 0 p.,r.:l ---Op., <X) E-o E-o""' <r.:< :;....r.:.. E-oz o'""' 0 ...:I ""' > VELOCITY DISTRIBUTION 390L------L----~------~----_L ______ L_ ____ _L ______ L_ __ ~ DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 13. --Cross section 8+00 showing velocity distribution and bedload-transport rates, airport site, August 16, 1979. Top: velocity distribution at 80 percent of depth. Bottom: bedload-transport rates. 21 Since only part of the total flow was measured and only part of the total channel width active in bedload transport was sampled, no comparison between these data and previously col)ected bedload data (Burrows, Parks, and Emmett, 1979) on the Tanana can be made. Particle-size distribution for the bedload is shown for the two days in figures 14 and 15. Approximately 85-95 percent of the material in transport was in the sand range ( > 0.062 mm < 2.0 mm) and the modal particle size was in the size fraction of 0.25 mm to 0.5 mm. DATA FOR SITE AT DIKE NEAR NORTH POLE, ALASKA Figure 16 is an aerial photograph of the dike constructed on the north bank of the Tanana River near North Pole. Shown are the reach of river past the dike and the part of bank where the several types of experimental revetment have been placed. Figure 17 is a plan sketch of the same area showing stationing, edge of bank, location of revetment, and the arbitrary right bank reference, as surveyed by CRREL. The Corps of Engineers revetment extends from station 0+00 to 6+80, the CRREL revetment from station 6+80 to 8+25, and unprotected bank from station 8+25 to 10+00. Measurements and samples were taken at stations 4+50 and 7+00. Figures 18a and b show the partial sections as they were measured on August 17 and October 3. Vertical-velocity distributions are plotted in figures 19a and b for section 4+50 and in figures 20a and b for section 7+00. Velocities shown are for the points measured. The mean for each vertical is shown above the station. Velocities at 80 percent.of the depth and bedload-transport rates across the measured main channel at section 4+50 for August 17 are shown in figure 21. For this measured part of the channel, the average transport rate gives a daily load of 450 tons at a water discharge of 26,800 ft 3 /s. Again, no comparison of this data should be made with previously collected data (Burrows, Parks, and Emmett, 1979) representing total flows and total bedload in the Tanana. Composite particle-size distribution of this sample is shown in figure 22. The gradation of the particles comprising the bedload at this section is approxi- mately the same as that at the airport section. 22 100 r"l N ,_. rl.l r"l > r"l ,_. rl.l ~ ~ p:: r"l z ,_. r:. 50 N E-<ft w ::r:: C!:l ,_. 40 ~ >< 30 J:Q r:cf C!:l ES 20 z r"l C) 10 p:: r"l ~ 0 .01 SIEVE SIZE, IN MILLIMETERS Figure 14.--Composite particle-size distribution of bedload, June 25, 1979, section 8+00, airport site. 100 l'tl 90 N ...... tf.) l'tl 80 > l'tl ...... tf.) z 70 < l:I: 8 ~ l'tl z ...... N r;.. ~ e-.· l:I: C!:l 40 ...... ~ :>t 30 t:Q l'tl. C!:l ~ 20 z l'tl C) 10 ~ l'tl ~ 0 .01 .1 1 10 100 SIEVE SIZE, IN MILLIMETERS Figure 15. --Composite particle-size distribution of bedload, August 16, 1979, section 8+00, airport site. Photo by North Pacific Aerial Surveys, Inc . Courtesy of U.S .Army Corps of Engineers Figure 16. --Data-collection site at dike near North Pole . 25 N en } I 6+80 to 8+25 \ ~~8_+~25~to~l~O+_O~O~---+~C~R~R~E~L~e~xp~e~r=i~~~- unprotected bank me_::al revetmen\ I Right b•nk ''''"'"''~ 0 100 200 FEET ~~--~.1,_-L•--,~---Ti' 0 20 40 60 METERS §' ,.:; Figure 17. --Plan sketch showing location of edge of bank at dike site as surveyed by CRREL. 470 465 E-< ril ril r:z:. 460 z ...... :i 455 0 ...... E-< < > ril ...:1 ril 440 800 700 August 17, 1979 --7-, October 3, 1979 I 600 500 400 300 200 100 0 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 18a.--Cross section 4+50 at dike site. 27 470r---~------~~------~ 440~~~------~~------~ 200 100 0 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figlire 18b.--Cross section 7+00 at dike site. E-< ril ril r.:.. 465 z 460 ...... :i 0 E=: ~ 455 ril ...:I ril 5'.8 5.4 6.1 5.8 6.3 6.1 6.5 6.1 5.6 5.8 4.6 4.8 4.4 5.4 5.8 6.1 5.0 4.4 4.0 3.8 4.0 4.6 4.0 August 17,1979 V = MEAN VELOCITY 2-v 3.6 3.8 3.1 2.7 VELOCITIES IN FEET PER SECOND 445~----~~--~~----~~-----L------~----~~----~------~ 100 40 20 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 19a.--Velocity distribution near right bank, at cross section 4+50, dike site. E-< ril ~ 460 z ...... :i 0 E=: 455 < > ril ...:I ril 450 2.5 2.7 2.4 3.0 2.7 2.9 3.3 3.4 3.2 2.9 2.6 3.1 2.9 3.0 3.3 2.2 2.9 3.1 3.4 2.6 3.1 2.7 3.1 3.1 3.1 2.9 3.0 3.0 2.6 October 3, 1979 V = MEAN VELOCITY VELOCITIES IN FEET PER SECOND 160 140 120 100 80 60 40 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET 20 Figure 19b.--Velocity distribution near right bank, at cross section 4+50, dike site. 28 470 7.4 6.8 7.8 6.2 5.8 '·l E-< 5.0 r:<l 6.1 r:<l 6.8 5.4 ~ 7.8 7.1 6.8 z 4.4 ...... 5.8 • 460 3.0 z 6.5 2.4 0 6.1 7.1 7.1 ...... ~ 6.1 &; 455 6.1 ..:I 6.1 7.1 7.0 r:<l 6.1 3.9 6.1 6.1 3.8 4.8 V = MEAN VELOCITY VELOCITIES IN FEET PER SECOND 445 160 20 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 20a.--Velocity distribution near right bank, at cross section 7+00, dike site. 465 V=4.3 E-< r:<l 6.5 6.0 5.3 4.6 r:<l ~ 6.0 5.3 z 460 5.6 5.3 ...... z 5.4 5.3 0 ...... ~ > r:<l ..:I r:<l 5.0 5.3 455 5.0 5.4 2.6 2.7 450 VELOCITIES IN FEET PER SECOND 445L-----~------L-----~------~----~------~----~ 160 140 120 100 60 40 20 DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 20b.--Velocity distribution near right bank, at cross section 7+00, dike site. 29 VELOCITY DISTRIBUTION 445~-------L--------L-------~--------~------~--------~------~~------~ o.Ior--------,---------r--------,---------r-------~---------r--------,---------, 0.02 "' ..... 0 0 "' ------o-- "' 0 0 .., .., • q g g 0 0 • • 0 0 00 00 0 0 AVERAGE TRANSPORT RATE= 0.0145 --·r------------.----- g ~ 2 0 q 0 0 0 0 so~o~----~7o~o~~L-~~--~--~~_J--~,4~o~o--~--~~_J--~~----~~~--~--~o DISTANCE FROM RIGHT BANK REFERENCE, IN FEET Figure 21. --Cross section 4+50 showing velocity distribution and bedload-transport rates, at dike site, August 17, 1979. Top: velocity distribution at 80 percent of depth. Bottom: bedload-transport rates. 30 8 :i E-< ll. .6 >:<:! oo E-<z Zo 4 >:<:it_) t..)>:<l ~00 >:<:!~ ll.>:<l ~ll. E-<E-< <~ ><~ E-<z 6- 0 ...:l >:<:! :> w ...... SIEVE SIZE, IN MILLIMETERS Figure 22. --Composite particle-size distribution of bedload, August 17, 1979, section 4+50, dike site. REFERENCES CITED Buchanan, T. J., and Somers, W. P., 1969, Discharge measurements at gaging sta- tions: U.S. Geological Survey Techniques of Water Resources Investigations, book 3, chapter 8, 65 p. Burrows, R. L., Parks, Bruce, and Emmett, W. W., 1979, Sediment transport in the Tanana River in the vicinity of Fairbanks, Alaska, 1977-78: U.S. Geological Survey Open-File Report 79-1539, 37 p. Emmett, W. W., 1979, A field calibration of the sediment-trapping characteristics of the Helley-Smith bedload sampler: U.S. Geological Survey Open-File Report 79-411 ' 96 p. Helley, E. J., and Smith, Winchell, 1971, Development and calibration of a pres- sure-difference bedload sampler: U.S. Geological Survey open-file report, 18 p. 32