7075 - Laserfiche WebLink

Home Browse Search

TABLE 1 Mean Annual Streamflow and Computed Sediment Yield (Andrews, 1978) Station/Site Area Mean Mean Annual Sediment Load (sq mi) Annual (tons/year) Discharge Suspended Bedload Total (cfs) Little Snake River 3,730 575 1,300,000 70,000 1,400,000 River near Lily, CO Yampa River near 3,410 1,550 Maybell, CO 420,000 120,000 540,000 Yampa River at -- 2,125 Deerlodge Park, CO -- -- 2,000,000 The above table shows that the Little Snake and Yampa River sub-basins are roughly equal in drainage area, but the distribution of sediment and water yield is very different. The Little Snake River sub-basin supplies 270 of the annual runoff to Deerlodge Park and 707. of the sediment load. In contrast, the Yampa River sub-basin supplies 73% of the annual runoff at Deerlodge Park but only 27% of the sediment load. Andrews (1980) selected 15 gaging stations computed the effective discharge at each s as the increment of discharge that transpo annual sediment load over a period of year were used; again developed using measured bedload transport. in the Yampa River basin and ite. Effective discharge is defined its the largest fraction of the s. Total sediment transport curves suspended sediment data and estimated The effective discharges were equaled or exceeded on the average of between 1.5 days/year and 11 days/year (0.4% to 3.0%, respectively). Recurrence intervals of the effective discharges ranged from 1.18 to 3.26 years. Variation in the duration of effective discharge between stations is explained, in part (about 50%), by the skewness of the distribution of daily streamflows. As drainage area increased, the relative abundance of high flows or skew of the distribution of streamflow increases. As a result, the effective discharge becomes less frequent as drainage area decreases.