The chemistry, mineralogy, and rates of transport of sediments in the ...

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6 with a greater susceptibility to erosion : Paleozoic i 3, Mesozoic • S, Cenozoic • 6, Quaternary • 2 . Crude estimates of this parameter were determined from physiographic maps and discussion in Bostock (1964), Inland Waters Directorate (1973) . The multiple linear regression analyses were performed by the "step up method" described in Chapter 13 of Snedecor and Cochran (1971) . Rates -of transport were regressed on Ad-initially, and then subsequent variables were added one at a time . Only those variables causing a significant increase in R from one step to another were retained . Thus, only the fewest number of variables which significantly explained the variance in rate of transport were retained . These calculations were performed on a Hewlett-Packard 9810, by means of a Stat-Pac program . RESULTS Suspended Sediments The range of concentration of suspended sediments in the selected rivers and streams varied from
7 The total mass of sediments removed yearly from the watershed of each river, is given in Table 3 . The rivers of Group 1, with large watershed areas and annual discharges, carried vast amounts of sediments compared to the smaller rivers and streams of Group 2 . In order to compare natural erosion .rates of sediment from large and small watersheds, the annual mass of sediment transported was divided by the watershed area of the river . This resulted in an estimate of the average annual mass of sediment carried away from a square kilometer of the land drainage area of a river . This treatment of the data (Table 3) indicates that the watersheds of small streams yielded much less sediment to the stream-per unit watershed area than did the large watersheds in Group 1 . The annual mass of sediment transported per unit watershed area was positively related to annual discharge (Fig . 2) . Rivers with annual discharges greater-than about 5 km3yr-1 transported 36 to 126-metric tons of suspended sediment per km2 of watershed area, while rivers and streams with discharges from 0 .01 to 2 km3yr-1 transported 0 .2'to 12 metric tons of sediments km-2yr-l . Some idea of the seasonal variation in these parameters can be obtained from Fig . 2, where,-,3 years of discharge and sediment transport are given for the Willowlake River, Liard River at Ft . Liard, and South Nahanni River above Virginia Falls : . . Bedload We tried to estimate the annual movement of cobbles and small boulders in the bed- of Jean Marie River (50'km SE of Ft . Simpson) . Jean Marie River has a watershed area (2,960 km-2) a little larger than Martin River, and is probably similar to Martin River in its annual discharge pattern, although it carries very low concentrations of suspended sediments (see Campbell •et aZ ., 1975) . We recovered over 90% of the painted stones that were placed in . the stream bed, and found that the maximum distance moved in a year was less than 2 meters . Small stones (0 .10 kg) moved the most, while larger boulders (10-27 kg) moved very little (maximum of 0 .2 m for 10 kg stones) or not at all . Oxygen Demand of Sediments in Water Sediments from the banks of, the Harris River do consume measurable .amounts of 02 from water at 20-220C in the dark (Table 4) . These data indicate that 02 consumption per unit time was not related to the mass of sediment added, nor to the fraction of organic matter in the added sediments . However, Table 4 does indicate that sediments added to oxygenated water may cause a reduction in 02' concentrations over a period of 10-30 days . Similar experiments were .done in situ on Harris River on 1 August 1974 . In this small, clear water stream, sealed, clear glass bottles (with varying amounts of suspended sediments added) were suspended in the
Page 1 and 2: Department of the Environment Minis
Page 3 and 4: iii TABLE OF-CONTENTS Page List of
Page 5 and 6: V TABLE 8 . Page Mean annual rates
Page 7 and 8: vii LIST OF FIGURES Page Figure 1 .
Page 9 and 10: ix ABSTRACT Brunskill, G . J ., P .
Page 11 and 12: xi RESUMt Brunskill, G . J ., P . C
Page 13 and 14: 1 INTRODUCTION In regions of northe
Page 15 and 16: 3 Stream and river bottom sediments
Page 17: Annual rates of transport were obta
Page 21 and 22: 9 Only two clay minerals were found
Page 23 and 24: 11 increased sediment concentration
Page 25 and 26: 13 changes in albedo, and the gener
Page 27 and 28: 15 Increases in the concentrations
Page 29 and 30: 17 which is positively related to w
Page 31 and 32: 19 and velocity (Fig . 1) . For the
Page 33 and 34: 21 It will be necessary to quantify
Page 35 and 36: 23 CONCLUSIONS 1 . For selected riv
Page 37 and 38: 25 REFERENCES Abrahams, A . D . and
Page 39 and 40: 27 Corbel, J . 1964 . L erosion ter
Page 41 and 42: 29 Hughes, 0 . L ., J . J . Veillet
Page 43 and 44: 33 McRoberts, E . C . and N . R . M
Page 45 and 46: 33 Tarnocai, C . 1973 . Soils of th
Page 47 and 48: , 35 e TABLE 2a . Slopes ') and int
Page 49 and 50: 37 i TABLE 2c . Slopes (b) and inte
Page 51 and 52: i 39 b TABLE 3 . Average annual mas
Page 53 and 54: 41 v b TABLE 5 . Cation exchange ca
Page 55 and 56: N c . P TABLE 7a . Ranges of concen
Page 57 and 58: I a m r TABLE 8 . Mean annual rates
Page 59 and 60: 01 TABLE 10. Mean annual rates of t
Page 61 and 62: 49 TABLE 12 . Significance of regre
Page 63 and 64: TABLE 14 . Mean concentrations of s
Page 65 and 66: 9 Q TABLE 16 . A comparison of annu
Page 67 and 68: TABLE 17 . cont'd River Year Date S
Page 69 and 70:
S TAME 17 . cont'd River Year Date
Page 71 and 72:
TABLE 17 . cont'd River Year Date Q
Page 73 and 74:
It • TABLE 17 . cont'd River Year
Page 75 and 76:
TABLE 17 . cant 'd River Year Date
Page 77 and 78:
2 =0.67 100,000- N E Y a 10,000- Y
Page 79 and 80:
c 11 I C- 10 - E n I, 0 10- E e 0.1
Page 81:
II (m 3 vnnr - ' v In'6 1 r r, m A
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