Examine the impact of land use and land cover changes on peak discharges of a watershed in the midwestern United States using the HEC-HMS model
Shunfu Hu, Prasanna Shrestha
Abstract
Economic development and urbanization can cause the increase of impervious surfaces, thus changing the hydrological processes in a watershed. To understand how land use and land cover (LULC) change in the watershed impacts the hydrological processes, researchers rely on the development of hydrologic models to simulate the physical behavior of the watershed from rainfall to runoff. In this paper, we successfully calibrated and validated HEC-HMS models, coupled with Arc Hydro and HEC-GeoHMS to examine how the LULC changes between 2001 and 2011 in the Richland Creek Watershed (RCW) located in the St. Louis Metropolitan Area impacted the stream peak discharges. The models have been further evaluated with the Nash-Sutcliffe Efficiency values and they showed good performance. The results showed that there was an increase of the impervious surfaces of 11.21 percent from 2001 to 2011 in the RCW and the peak discharges increased about 125% to 175%. This research enhanced the understanding of the relationships between LULC changes and peak discharges in the RCW. The model can be used to assist policy makers for predicting flash flooding in the watershed and mitigating the property damages due to the flash flooding.