Evaluation of the Effects of Low Impact Development on Base Flow in an Urbanized Watershed Using HSPF

摘要

Impervious surfaces have become common due to traditional urban development and construction. However, it may affect the urban ecosystem and have negative impacts on the quantity of base flow due to the infiltration decrease. Currently, low impact development (LID) has received increasing attention because it is able to increase base flow by increasing the infiltration rate. However, the effects of LID on the base flow in urbanized areas have not been fully discussed. In this paper, the Hydrological Simulation Program-FORTRAN (HSPF) is proposed to evaluate the impact of LID planning on base flow of an urban area in Shenzhen, China. Meteorological data, a topographical map, land use data, and remote sensing data of this study area are used as inputs in the model. Besides, three months of observed hydrologic data of the watershed in 2015 is used for calibration and validation. The model, coupled with a digital filter method, is used to analyze the change of base flow due to urbanization with and without LID impacts. The results indicate that, under extreme ideal circumstance, the maximum area (48%) of impervious surface is retrofitted to LID. The maximum potential base flow increase in the study area is 15%, which is far more than that in realistic world.