Calculation Models on Erosion and Deposition of Main Stem Tarim River and Its Analysis

Based on analysis on the cross-section forms and the characteristics of water and sediment movement in flood plain and main channel, river cross-section is divided into three parts: low-water channel, main channel and flood channel. Water and sediment transport capacity is relatively small in low-water channel; and it is larger in main channel which is suitable for water and sediment transport; as for flood channel, the discharge capacity is increased in spite of water and sediment transport capacity reduced. According to the field data for many years, the sediment transport rate is related to discharge in the following equation. Q_s = KQ^a Considering shortage of basic data and serious water losses (such as flood overflow, diversion, seepage and evaporation), a set of calculation models of water and sediment transport which would be applied to the different cross section forms (such as low-water channel, main channel and flood channel) has been put forward based on the above derived sediment transport rate formula. Using those models, the erosion and deposition of the main stem Tarim River has been calculated and analyzed finally.