西南地区水库生态环境特征与研究展望

西南是我国水资源富集区,随着清洁能源"西电东送"、城镇化建设和水利水电发展战略的持续实施,西南地区水库的数量将不断被刷新,水库数量快速增长与日益凸显的生态环境问题存在突出矛盾。西南地区水库具有独特的地质地理背景和生态环境特征,主要表现在:1)具人工建造属性,水环境与生态系统演化起点不同于天然湖泊;2)水位逆周期人为调控,消落带生态功能退化;3)亚深水型,水体季节性分层控制了湖泊的关键物理、化学和生物过程;4)沉积物有机质和营养盐蓄积量大,潜在二次污染风险大;5)物质循环的累积效应对水库及下游水环境与水生态安全具重要影响;6)水体富营养化与重金属污染叠加、复合;7)物质循环和生物过程受多界面作用控制。当前对西南地区亚深水型水库生态环境的研究远落后于东部浅水湖泊,亟待对其生态环境演变过程与规律开展深入研究,研究建立与之适宜的水环境演变理论和治理技术体系,为该类型水库生态环境保护与治理提供有效科技支撑。

Eco-environmental Characteristics of Reservoirs in Southwest China and Their Research Prospects

Southwest China is rich in water resource. With persistent implementation of clean energy electricity transmission from west to east, the urbanization construction, water conservancy and hydropower development strategy, and number of reservoirs in Southwest China will continue to be refreshed. However, contradictions exist between rapid growth in reservoir number and increasingly prominent eco-environmental problem. Reservoir has unique geologic background and eco-environmental characteristics as follows. 1) With man-made attributes, the water environment and ecological system evolution starting point are different from natural lakes; 2) Counter cyclical artificial regulation of water level leads to ecological function degradation of Hydro-Fluctuation Belt; 3) Seasonal stratification controls the key physical, chemical and biological processes in these sub-deep water reservoirs; 4) Sediment is rich in organic matter and nutrients and thus has notable potential release risk; 5) Cumulative effect of the material cycle has an important influence on water environment and ecological security of reservoirs and downstream water; 6) Water eutrophication and heavy metal pollution are tightly interlocked; 7) Multi-interface function controls the material cycle and biological processes. Research on eco-environment of sub-deep water reservoir is far behind that of the shallow lakes in East China. It is desirable to carry out intensive study on evolutionary process and inherent law of the eco-environment in southwestern reservoirs, so as to establish effective water environment theory and treatment technology system, providing strong scientific support for eco-environment protection and treatment.