改进河流压力指数法及在河流健康评估中的应用

水文情势是河流生态系统的基本属性及重要驱动力,其年内及年际变化会影响河流生态系统的正常结构与功能。当前水文变化评估已被国内外学者列为河流健康评估的重要内容。河流压力指数(FSR)法以受干扰前后连续月径流系列为基础,采用10项指标评估人类干扰下河流水文情势的变化特征,但对河流水文变化生态过程的表征存在一定局限性。针对闸坝工程建设、水电资源开发等对河流调节的不稳定性及无规律性,从河流径流系列、指标算法以及指标优选等对FSR进行一系列优化改进。在南方某流域河流健康的评估应用中发现,改进型河流压力指数法适用于日径流系列并可如实反映河流受干扰的实际情况,使得河流健康评估更符合实际;优选后的5项指标充分代表了原10项指标的生态学意义及评分结果,更有利于FSR法的应用与推广。

Improved Flow Stress Ranking and its application in river health assessment

Hydrological regime is the basic property and an important driving force of river ecosystem. Its annual and interannual variations can affect the normal structure and function of river ecosystem. At present, the assessment of hydrological variation is regarded as an important content of river health assessment. Flow Stress Ranking (FSR), based on continuous monthly runoff series before and after the human interference, uses 10 indicators to assess the variation characteristics of river hydrological condition under the human disturbance. However, this method has some limitations in characterizing the ecological processes of river hydrological variation. This paper, focusing on the instability and irregularity of stream adjustment influenced by dam construction and development of hydropower resources, optimizes and improves the river runoff series, index algorithm and index optimization in FSR. It is found that in the application of river health assessment in a medium-sized basin in the south China, the Improved-FSR is applicable to daily runoff series to reflect the actual situation of river disturbance, which makes the river health assessment more practical. The 5 optimized indexes can fully represent the ecological significance and the score of the 10 former indexes, which has better application and popularization.