水利工程对长江荆南三口水系连通功能变化的影响

Effect of Hydrological Projects on Hydrologic Connectivity in the Three Outlets of Southern Jing River

为了揭示荆南三口地区水利工程与水系连通功能的定量关系,基于1954、1975、1990、2008和2016年5期的水利工程与水系连通功能的相关数据,运用集对分析和相关分析等方法,定量评价了水利工程对长江荆南三口水系连通功能的影响,结果表明:1)区内外水利工程与多年日均径流保证率、河道断流率、输沙效率的相关系数(R2)均>0.5,皆达到显著性水平。2)自然功能3个模块的联系主值数基本呈下降趋势,但物质能量传递功能与生态维系功能下降尤为明显。1990年之前物质能量传递与生态维系功能处于一个较好的状态,1990年后这2项功能的等级已下降至"差";社会功能3个模块的联系主值数的变化各不相同。洪涝防御功能一直处于上升状态,而水资源调配功能和水能与水运资源利用功能都在1954—1990年呈下降趋势,1990年后,水资源调配功能逐渐回升,水能与水运资源利用功能持续下降。3)1954—2008年自然功能等级和综合功能等级都有所下降,直到2016年才稍有回升,但升幅较小,等级较低;社会功能等级在1954—1990年较低,2008年以后回升,且明显高于自然功能等级。

The aim of this study is to examine the quantitative relationship between hydrological projects and the functions of hydrologic connectivity.This investigation is based on the data of hydrological projects and hydrologic connectivity for 1954,1975,1990,2008 and 2016,using set-pair and correlation analysis to quantitatively evaluate the effect of hydrological projects on hydrologic connectivity in the Southern Jing River.The results show that: 1) the correlation coefficient (R^2) between the hydrological projects both inside and outside the region and the rate of cutoff,annual mean runoff and sediment runoff are determined to be above 0.5.This indicates a significant correlation between these factors.2) The relative main value of the three modules of natural function presents a decreasing trend,especially the functions of material/energy interchange and ecology maintenance,which declined rapidly from an acceptable position to a“poor”level since 1990.The relative main values of the three modules of social function presented different trends.Throughout the study period,the function of flood prevention exhibits an increase while the function of transport and resource utilization shows a decrease.The function of water resource distribution initially decreases prior to 1990 followed by an increase after 1990.3) The level of both natural function and comprehensive function exhibit a decrease during the period 1954-2008 and this situation did not reverse until 2016 during which a small increase was recognized while the level was still low.The level of social function was also low during 1954-1990.However,a significant increase was observed after 2008 and the level was much higher than that of the natural function.