Case Study of Distributed Hydrologic Model for Soil and Nutrient Loss Estimation in Small Watershed

Abstract

In this paper, the soil erosion and nutrient loss from a watershed nonpoint source was studied as a system. First, a digital watershed, a hydrological process within a unit, as well as the process of convergence were analyzed and a hydrological model was constructed to simulate changes in watershed runoff. Then, taking the runoff estimates as the input to a nonpoint source pollution analysis, the pollutants lost from the study area were calculated and analyzed. Finally, a sensitivity analysis was performed on factors related to nonpoint source pollutants in the study area. The results show that nitrate is the major form of nitrogen lost, and that slope and vegetation coverage are the biggest factors impacting all runoff, nutrient, loss and soil erosion.