Prediction of stream channel erosion potential

Field tests using a submerged jet apparatus were conducted to determine the erodibility coefficients in alluvial soils along stream channels, The soil s tested ranged from cohesive clay soils to non-cohesive sandy soils. In ad dition to performing the jet test at thirty sample sites, laboratory tests on soil samples taken from each site were done to determine soil bulk densi ty, antecedent soil moisture, Atterburg limits, and grain size distribution , Regression analysis was performed on these parameters against the erodibi lity coefficient to assess whether laboratory testing could be used to exte nd the submerged jet test results upstream and downstream. Best results wer e obtained with equations stratified by percent clay and soil activity with multiple correlation coefficients ranging from 0.78 to 0.96. Preliminary e fficiency of the equations was 64 percent (coefficient of determination .71 ) when compared to an independent data set. Use of the erosion coefficient in a stream channel degradation model is shown.