A mathematical model, based on the theory of sediment transport combining with the principles of hydrology, meteorology, geomorphology and the characteristics of sediment in the Middle Yellow River, has been established. The thesis emphatically solved the geomorphologic and geographical differences, and the differentiated distribution of precipitation in terms of time and space in the watershed. To formulate this model, Huangfuchuan basin is divided into 3 small watersheds and 14 subwatersheds including 510 small areas with different geomorphologic properties by using the remote sensing technology and analyzing the data of the on the spot investigation. The precipitation in early days was taken into account when selected the runoff coefficients. The results of runoff and sediment yields calculated by this model for single rainstorm agree quite well with the measured data. The sediment yield of the gullies from each small area are calculated by using the model according to its specific conditions. The reasons of the changes of runoff and sediment yields were also analysed. It was shown that the calculated results of this mathematical model is reasonable. Therefore, the model can predict the changes of the runoff and sediment yields if the processes of precipitation are known, and can be spreaded to the calculations of the runoff and sediment yields in single rainstorm in loess region of the Middle Yellow River.
Journal of Sediment Research
changes of the runoff and sediment yields