丹江口水库调水对汉江中下游四大家鱼繁育的影响研究

Influence of Reservoir Water Diversion on Four Major Chinese Carps in Middle and Lower Hanjiang River

丹江口水库加坝扩容和调水工程的实施引起下游水文条件变化,影响汉江中下游四大家鱼繁育生境。本文总结已有研究,结合实测资料分析,提出影响汉江四大家鱼产卵的主要水文要素,依据丹江口水库加高调水的运行规则,模拟分析了丹江口水库加高后两种调水规模下,汉江中下游主要水文站点的水文情势变化,并结合水文情势的变化特征,分析了调水后可能对汉江中下游产漂流性卵鱼类的影响,研究表明丹江口加高调水后,汉江中下游7～8月涨水过程的涨水次数和总涨水天数有所增加,但日平均涨水幅度显著下降;而涨水幅度的降低是导致坝下游产漂流性卵鱼类产卵规模减少的诱因,故调水工程实施后,汉江中下游产漂流性卵鱼的种群及产卵量可能进一步减少。

Water diversion project of Danjiangkou reservoir would change the hydrological condition and influence the habitat of four major Chinese carps in middle and lower Hanjiang River. This paper summarizes the existing research and analyzes the measured data, and then discusses the main hydrological elements that affect the four major Chinese carps laying eggs in downstream river. Based on the different operation rules of the reservoir, the hydrological regime changes in middle and lower Hangjiang River reach are simulated and the influence of water diversion on four major Chinese carps in downstream is analyzed. The research shows that times and days of flow rising process would increase from July to August in middle and lower reaches of Hanjiang River, but daily average of flow rising would decline significantly which is the primary cause of number of eggs-laying decrease of fish with pelagic eggs at downstream of reservoir. The number of eggs-laying and population of fish with pelagic eggs would further reduce in middle and lower Hanjiang River.