深圳河流域城市化对河流水文过程的影响

Effect of Urbanization on River Hydrological Process in Shenzhen River Basin

深圳河流域是典型的高速及高度城市化区域。基于1988—2006年长时间序列降雨资料,借助RS和GIS技术,通过SCS模型对该流域降雨径流关系进行模拟,并结合流域内常住人口污水排放分析,研究城市化对流域天然径流深、下垫面径流系数和年径流总量的影响。研究结果表明:20年来深圳河流域土地利用结构由农业用地迅速向城市建设用地转化,流域人口增加导致排河污水量增幅达到2.56倍;天然径流深呈现逐年上升趋势,并且与降雨量表现出较高的相关性,依据M-K突变分析得到1993年为天然径流深突变年份;土地利用导致径流系数向高值发展,但强降雨弱化了径流系数对于径流量的影响;年径流总量整体呈现增大趋势,主成分分析表明降雨是影响径流总量的主要因素,但流域土地利用和人口的城市化效应不可忽略。

henzhen River Basin is a typical area with high speed of development and high degree of urbanization.Based on the rainfall data from 1988–2006,the relationship between rainfall and natural runoff was simulated by the Soil Conservation Service model with RS and GIS technology.Furthermore,the natural runoff,runoff coefficient and annual runoff were analyzed including the effluent of wastewater produced by the permanent people living in the basin.Results show that agricultural land was quickly converted into built areas and the volume of wastewater was increased more than two times.The natural runoff was increasing year by year,which was closely related to the rainfall with the break point in 1993 calculated by Mann-Kendall method.The runoff coefficient was also rising influenced by the conversion of land use patterns,which effect on the runoff was weakened by the heavy rain.Finally,the annual runoff was enlarged.The Principal Component Analysis showed that rainfall was the most important factor of runoff volume,but the influence of the urbanization of land use and population can＇t be ignored.