秦淮河流域水系结构及连通度变化分析

Analysis on variation of water system structure and connectivity of Qinhuai River Basin

为定量分析城镇化所导致的河网结构及水系连通变化,通过计算1990年、2000年、2010年和2015年4个时期秦淮河流域的河网密度、水面率、河网复杂度、河网稳定度、河网连通度、水文连通度,得出秦淮河流域水系结构演变过程及连通度变化规律,并运用统计学方法得到水系结构指标与水系连通度之间的联系。结果表明:近25年来,秦淮河流域河网密度、水面率均呈不断减小趋势,河道呈现主干化特征,流域河网整体规模呈萎缩趋势,水系连通变化与河网结构变化总体趋势一致,均呈降低趋势,且其变化与水面率、河网密度和河网复杂度具有显著相关性。

To quantitatively analyze the variation of river network structure and water system connectivity caused by urbanization,the river network density,water surface rate,river network complexity,river network structural stability,river network connectivity,and hydrological connectivity of the Qinhuai River Basin in 1990,2000,2010 and 2015 were calculated.The evolution process of the water system structure and connectivity in the Qinhuai River Basin were obtained.The statistical method is used to obtain the relationship between the water system structure index and the water system connectivity.The results show that the river network density and water surface rate in the Qinhuai River Basin have been decreasing continuously in the past 25 years.The river channel is characterized by main trunking.The overall scale of the river network in the basin is shrinking.The water system connectivity variation is consistent with the overall trend of river network structure variation,both showing a decreasing tendency.The change is significantly correlated with the water surface rate,river network density and river network complexity.