东江流域土地利用变化对径流的影响分析

Assessing Hydrological Impact of Land Use Change in the Dongjiang River Basin

将流域水文模型HSPF与元胞自动机-马尔科夫(CA-Markov)土地利用预测模型结合,定量评价了东江流域未来土地利用变化的径流响应;并且模拟分析了不同降雨情景下土地利用变化的水文响应。结果表明:HSPF模型可以较好的模拟东江流域的月径流过程,可用于东江流域长期水文变化的评价与研究;未来土地利用变化引起的总径流的改变较小但是地表径流的变化较显著;未来土地利用变化情景下高、低流量值都有所增长,随着城镇建设用地面积比例的进一步增加高流量值随之增长而低流量减少;随着降雨量的增加,径流对于未来土地利用变化的响应程度减弱,降雨量减少,未来土地利用变化的水文效应增强;总的来说,4种降雨情景下未来土地利用变化对总径流的影响都不大,但是对地表径流有较显著的影响。研究过程和结果可为东江流域水资源规划及相关管理决策提供参考。

A comprehensive watershed model—the Hydrological Simulation Program FORTRAN （HSPF）was set up and calibrated for the Dongjiang River basin,which was used to quantitatively pre-dict runoff in response to possible future land use change,combining with a land use projection model （CA-Markov）and a daily rainfall stochastic simulation model.The calibration and validation of the HSPF showed a good fit and the calibrated model was applicable to simulating the monthly runoff in the Dongjiang River Basin.The future land use scenarios generated by CA-Markov model result in little change in total runoff but some noticeable changes in surface flow.Both high flow and low flow increase under the future land use scenarios,and high flow increases with the growth of urban construction land while low flow decreases.The run-off effects of land use change decreases with increasing rainfall,and increases with decreasing rainfall.The changes of total runoff due to land use changes are little under four rainfall scenarios,but while the changes of surface flow are significant.Simulation hydrological change by connecting a land use prediction model and a semi-distributed hydrological model can be a good decision support tool for water management at a basin scale and capable of long-term scenario-based assessments.