Total bed material load equation for high gradient rivers

A new total bed material load equation for high gradient rivers located in mountainous areas was developed using multiple linear regression analysis. This analysis was executed using the SPSS software package. The hydraulics and sediment database, which comprises a total numbers of 55 data sets, was collected from 21 rivers located in Malaysia with water surface slopes ranging from 0.002 to 0.027 m/m. The study reaches having graveled and cobble beds with Sampled rivers have diverse morphological characteristics such as cascade, step-pool, plane bed and pool-riffles. Regression models were selected based on four criteria (R-squared, adjusted R-squared, mean squared error and Mallow's Cp statistics). The accuracy of the developed equation was checked using the discrepancy ratio (the ratio of calculated values to measured values). The newly developed equation is best suited for rivers with a d50 value within the range of 2.00 mm-147.43 mm and performs with 55% accuracy when tested with high gradient river data.