大型水库水温分层影响及防治措施

大型水库的建成与投产,为我国的现代化建设提供了巨大的经济效益和社会效益.同时,大型水库特别是调节性能好的水库由于大量水体的蓄积,使水库在沿水深方向出现了有规律的水温分层现象.这种水温分层现象使库区内水生生物结构发生变化,影响库区的水质.又由于水电站泄水设施因发电要求而使泄水口高程较低,因此水库的水温分层使冬季下泄水温较天然情况高,而春、夏季下泄水温较天然情况低.下泄低温水可使鱼类在产卵、生长及捕食方面受到极不利的影响,造成鱼类资源的减产甚至某些鱼种的灭绝.下泄低温水还会对农作物产生＂冷害＂影响,造成减产甚至绝产.因此,在进行大型水电工程规划、设计、运行的同时应积极开展水库水温结构及下泄水温计算和研究,及时采取有效减缓低温水下泄的各项措施,以实现水资源开发利用和生态保护的＂双赢＂.

Effects of Water Temperature Delamination in Large-scale Reserviors and Protection Methods

The construction and operation of the large-scale reservior have enormous economic and social benefit for China.But the water temperature was come out to be layered along the depth in the large-scale reserviors especially that have better regulation performance because of the water cumulation.This phenomenon makes the construction of the hydrobiont changed and water quality affected.For the water discharge construction of powerplants,which always have low elevation of water intakes,together with the water temperature delamination make the temperature of discharge water usually higher than naturally situation in winter and lower in spring and summer.The lower temperature water has deeply negative effect on fish oviposition,grow up and predation and make the fish production reduced;furthermore,some fish species extincted;and also on agricultural crops.So the calculation and research on the water temperature structure of reservior and discharge water should be done during the planning,design and operation of large hydro projects in order to take some efficient methods to protect the ecological environment and realize the water resources development and utilization.