Assessing the Hydrologic Impacts of Land Use Change in the Taihu Lake Basin of China from 1985 to 2010

Abstract

In recent decades, the land use patterns in the Taihu Lake Basin (TLB) have undergone tremendous change. Assessing the response of land surface hydrological processes caused by land use change is conducive to basin water resource management and the prevention of urban flooding. The water yield under different land use scenarios in 1985, 1995, 2000, 2005, and 2010 were calculated by the STREAM model. During the study period of 1985–2010, the contribution of farmland to the total water yield decreased from 47.20% to 35.2%. The contribution of construction land to the total water yield increased from 10.50% to 25.82%. There was a significant spatial difference in the growth of the water yield in 1985–2010. The Pudong sub-region, Puxi sub-region, Yangchengdianmao sub-region, and the Wuchengxiyu sub-region, with relatively faster urban development, also had higher water yield growth rates. During the study period, the growth rate of water yields in towns showed a spatial clustering feature. MI increased from 0.22 to 0.38, indicating that this spatial clustering feature had an increasing trend. The results of an LISA analysis showed that there was a significant spatial difference in the growth rate of water yield in the TLB. The high growth centers are mainly located in the north of the basin, while the low growth centers are mainly located in the southwest of the basin. At the same time, the center of the high growth rate of water yield showed a certain trend of expansion and transfer. Regression analysis showed that urban development had a significant impact on water yield; for every increase of 1 km2 of construction land in the TLB, there was an increase of water yield of more than 300,000 m3. Further study indicated that the growth of local water production in TLB was much higher than the average value of the basin, and it was significantly related to the gross domestic product (GDP) per capita.