三峡库区水位变化下小江流域富营养化的时空变化特征

Research on Temporal and Spatial Variation Characteristics of Eutrophication in the Xiaojiang River Basin under the Change of Water Level in the Three Gorges Reservoir Area

自三峡水库运行以来,小江流域水华污染现象越发严重,对三峡库区水位变化、小江流域水质指标总氮、总磷和浮游植物体内总磷含量进行监测、分析。实验表明:①水华现象在三峡库区水位较低(163 m)且持续下降时发生频繁,在库区水位较高(173 m)且持续上升时发生频率明显减少;②小江流域春季较易爆发水华现象;③三峡库区水位调节对小江流域中游水华现象的发生影响最大,上、下游次之。因此,三峡库区水位的变化与小江流域水华的发生规律有很高的相关性,研究在三峡水库水位变化的条件下水库主要支流水华现象的时空分布特征,为三峡库区支流水体的水华特征识别及防治提供基础。

Since the operation of the Three Gorges Reservoir,the phytoplankton blooms in Xiaojiang River Basin has become more and more serious.This paper monitors and analyzes the change of water level in Three Gorges Reservoir area,the total nitrogen and phosphorus in Xiaojiang River Basin and the total phosphorus in phytoplankton.The results showed that:(1)The phytoplankton bloom occurs frequently when the water level in the Three Gorges Reservoir area is low(163 m)and continues to drop,and it decreases significantly when the water level is high(173 m)and continues to rise;(2)Phytoplankton blooms are easy to break out in Xiaojiang River Basin in spring;(3)The regulation of water level in the Three Gorges Reservoir area has the greatest impact on the occurrence of phytoplankton blooms in the middle reaches of Xiaojiang River Basin,followed by the upper and lower reaches.Therefore,the change of water level in the Three Gorges Reservoir area has a high correlation with the occurrence regularity of phytoplankton blooms in the Xiaojiang River Basin.The temporal and spatial distribution characteristics of phytoplankton blooms in the main tributaries of the Three Gorges Reservoir are studied under the change of its water level,which provides a basis for the identification and prevention of the phytoplankton blooms in the tributaries of the Three Gorges Reservoir area.