Study of Runoff Simulation Considering Effect of Human Activity on the Loess Plateau
黄土区人类活动影响下的 产汇流模拟研究

Human activity has great effect on runoff producing and conflux for basins and can not be neglected, especially for the day-scale hydrology modeling. Because of the special human activity on the Loess Plateau, the Yellow River's runoff has been decreasing from 1960's. Because of the complex land surface condition, the relationship of rain-off and runoff is very anomaly. Runoff is hard to be modeled by uniform experience formula. And what' s more, when the land surface condition changes, the experience formula loses its validity. Based on distributed hydrologic model, a grid-based lag-and-storage method, with consideration of the effect of human activity, is in detail shown, taking Chabagou (a typical watershed on the loess plateau) as an example. The digital terrain parameters are extracted from DEM(digital elevation model) with resolution of 950mx950m. The location of dams and reservoirs et al are distributed on the grids with their real location on the watershed in mind. The model also uses the mix-runoff-producing method, which considers the variation of runoff-producing area. The modeling results show the feasibility of this method. Model using the gird-based lag-and-storage method can consider the land change on grid-scale and reflect the condition of every periods, so it would make reasonable response to rain-off. With the effect of human activity on runoff brought into the distributed hydrologic model, the nature law of watershed and the effect of human activity on runoff can be deeply understood.