水系连通性的指标体系及其应用

Index system of water system connectivity and its application

水系连通指标是分析和评价连通性的关键。本文基于水系连通性的内涵、分析模式和连通机理,从河流边界、水流、泥沙、生态环境等方面提出河道(湖库)连通指标;根据连通指标的基本含义、计算过程和层次属性,将连通指标分为基本指标、过渡指标和功能指标,建立了水系连通性的功能评价指标体系;针对黄河下游河道的特点,建立了河道连通性的评价模型,对近几十年黄河下游河道连通性的变化过程进行了分析评价。评价结果表明,黄河下游河道连通性在1959年前为优等状态,1960年至1985年期间基本处于中等以上状态,1986至1990年代末由状态迅速恶化为差的状态,2000年以后河道连通性又逐渐恢复变为优良状态。

The connectivity index is the key for analyzing and evaluating the water system connectivity.Based on the connotation,analysis mode and connection mechanism of water system connectivity,the con⁃nectivity indices of river(lake)were firstly given from river boundary,water flow,sediment and ecological environment.Then,all kinds of connectivity indices are divided into basic indicators,transition indicators and functional indicators according to the basic meaning,calculation process and hierarchical attributes of indicators,and the functional evaluation index system of river system connectivity is established.Finally,ac⁃cording to the characteristics of the lower reaches of the Yellow River and the evaluation model of river connectivity,the evaluation results were given for the change process of the connectivity of the Lower Yel⁃low River in recent decades as follows.The connectivity of the Lower Yellow River is in the excellent sta⁃tus before 1959,and is basically in above middle status from 1960 to 1985,and becomes the poor status from the better status during the period between 1986 and the end of 1990s,and changes to better and ex⁃cellent status after 2000.