Application of Distributed Hydrology -Soil -Vegetation Model in Investigating the Impact of Land Use Change on Hydrology

Yi-Chieh Hsieh

This study aims to establish a Distributed Hydrology-Soil-Vegetation Model (DHSVM), then used the model to simulate the impacts of urbanization on runoff and evapotranspiration under different land-use scenarios in Jiu-Fen-Zi Redevelopment Zone, Tainan, Taiwan.

First, the relevant information about land-use of Jiu-Fen-Zi Zone was obtained. Then used the model to simulate and tested the evapotranspiration of the redevelopment zone before the development. Followed up to set up several land use scenarios for the redevelopment zone. According to the laws of impervious proportion of vacant land, if the redevelopment zone has been developed completely, then the land use scenario can be divided into two, low-density development and high-density development and gave different impervious rate, detention rate and detention decay rate for different blocks of these two land development scenarios in Jiu-Fen-Zi Zone.

The results show that the runoff after the development has an increasing trend compared to the runoff before the development, the tendency of increase in high-density development scenario is higher than the low-density development; the evapotranspiration after the development has a decreasing trend compared to the evapotranspiration before the development, the tendency of decrease in high-density development scenario is larger than the low-density development; while the daily peak-flow after the development also has an increasing trend compared to the daily peak-flow before the development, moreover, the tendency of increase in high-density development scenario is also higher than the low-density development. It reveals that with the increase of impervious area, runoff and the daily peak flow will increase, however, evapotranspiration will decrease.