Analysis on the Runoff and Sediment Yielding of “7.26” Rainstorm in 2017 in the Dali River Basin

Abstract

Hydrological regimes of the “7.26” rainstorm and flood in 2017 in the Dali River basin are illustrated, the runoff and sediment of the flood is calculated. The relationship between peak discharge, runoff and sediment of history floods and the corresponding mean rainfall and combined rainfall factor are established respectively. It is found that the point of “7.26” flood locates at the upper left or in the middle of the history points group. The results show that after the implementation of water and soil conservation and ecological restoration policy for several decades, the underlying surface of the Dali River basin has changed to some degree, but encountered with the high intensity rainfall such as "7.26", it will still generate the flood of high sediment concentration.