筑坝对河流生态系统的影响及水库生态调度研究

阐述了大坝建造对河流生态系统的影响途径:通道阻隔、水库淹没、径流调节、水温变化等,探讨了大坝建造对河流水文特性、化学特性、通道作用等生态功能的影响方式,并结合实际案例,提出对于已建工程可通过水库运行调度方式的调整,减缓其生态影响.其主要包括:结合河道及流域的生态保护目标采取不同的调度措施,保证合理的下泄生态流量;采取联合调度方式保持水库及下游水质;采取人造洪峰保护水生生物及鱼类资源;对湿地、湖泊进行人工补水等.建议水库运行调度应在考虑工程功能的同时,兼顾坝下及水库的生态功能,以达到流域水资源开发与保护流域健康的生态系统相协调的目的.

IMPACTS OF DAM CONSTRUCTION ON ECOSYSTEM AND DISPATCHES OF ECOLOGICAL WATER

According to the statistics of China Commission on Large Dams made at the end of 2003,there are 4694 large completed or under-construction dams with the dam height over 30 m in the country,intercepting over 5843 billion m3 of annual river runoff,namely,total capacity of reservoirs has reached to 20% of nation's annual runoff as a whole.Besides the acceleration of the water resource gradual development on Yangtze River,Yellow River and some other large rivers,more dams have been also built for water resource development and utilization towards medium and small watershed develop at very fast speed.The river possesses important ecology functions.The large dam construction across river produces many man-made changes over different kinds of circulation patterns and impacts on the ecosystem function of the river systems.Based on large dam's influence on the river ecosystem,a research is made on river ecological function changes on hydrologic features,chemical features and its channel function,etc..Combined with some projects practice,towards some constructed projects which has already created ecological impact,the authors proposed to make some adjustments on the reservoir's operation schedule mode,ease its ecological impact to reach a harmony between water resource development and healthy ecosystem protection of the river basin.The authors of this essay started from the large dam construction's impact approaches,through the analysis of impact phenomena the essence issue of water resource development's impact on river ecosystem was analyzed to include: the impacts of dams on hydrologic features,chemical feature and ecological function as well as the ecological response to the dams,etc..Based on the research,the authors propose the large dams ecological dispatch measures to ease the ecological impact of water resource development.