An Interpretation of Reservoir Sedimentation: I. Effect of Watershed Characteristics

Abstract

AbstractThe value of a water storage reservoir can decrease rapidly if its capacity is reduced by settling of eroded and suspended soil. Many factors determine the rate of this “siltation.” The purpose of this paper is twofold: to analyze to what extent the influence of the characteristics of the soils of the contributing watershed upon rate and type of sedimentation of reservoirs can be assessed quantitatively and to determine how these effects are correlated with other geomorphological factors.This study was made on 14 reservoir‐watershed combinations in Indiana and Illinois. The majority of the soils were silt loams. Under the conditions of this study, as the mean particle size decreases and the more uniform their particle size, the greater were the sedimentation rates. Sediment volume weight was found to be a function of particle size and organic matter content. The larger the mean particle size and the smaller the organic matter content of the sediment, the greater was the bulk density. The variation of sediment particle size and sedimentation rates could be evaluated quantitatively as functions of geomorphological and pedologic watershed characteristics.