近61年来长江荆南三口水系连通性演变特征

基于1955～2016年不同时期的长江荆南三口水系相关数据，从水系水力连通性强度、水系连通度和水系连通性水平三视角分析研究区水系连通变化过程。结果表明：2016年与1955年相比,（1）区域的水文连通性呈现下降的趋势，但变化幅度不大;(2)水系连通环度α、节点连接率β、水系连通度γ分别减少了45.45%、10.8%、8.46%，节点连接率β下降得最为明显；（3）基于水系自然社会功能的水系连通性（E）和基于水流阻力与水文过程（F）这两种水系连通性评价方法，联合评价了荆南三口水系连通性,两种结果均显示，研究区水系连通性均呈下降趋势，由1955年的0.2367和0.3434依次下降到2016年的0.1588、0.2517。该研究可为该地区实施河湖水系连通工程,修复河流生态系统提供理论参考。

Evolution Characteristics of River Network of the Three Estuaries of Southern Jing River in the Past 61 Years

Based on the data of river network of the Southern Jing river in different period from 1955 to 2016, the changing process of river network connectivity was studied from three aspects: strength of river system and hydraulic connectivity, river network connectivity and level of river network connection. Results show that comparing with 1955, in 2016, (1) the hydrological connectivity demonstrated a decrease trend but with moderate changes; (2) the circuitry of river network connectivity α, node-connection rate β, and river network connectivity γ were all decreased by 45.45%, 10.80% and 8.46%, respectively, of which the node-connection rate β demonstrated the most significant trend; (3) based on two methods evaluating the river network connectivity (e.g. ① E: river network connectivity with respect to the natural and social functions of river network, and ② F: river network connectivity with respect to the hydrological process and flow resistance) the river network connectivity of the three outlets of Southern Jing river has been collectively evaluated. Both of the results derived from the two individual method show that river network connectivity in the study area presented a downtrend that decreased from 0.2367 and 0.3434 in 1955 to 0.1588 and 0.2517 in 2016, respectively. The results of this article could be theoretical references for both river network or lake connectivity recovery projects and riverine ecological system restoration.