乌梁素海水体营养盐削减的空间变化规律研究

乌梁素海作为过水性湖泊,每年承接河套地区大量的农田退水。在降低营养盐浓度的同时,富营养化程度也大大提升。为揭示乌梁素海水体营养盐削减的空间变化规律,研究采集20个监测点的100份水体样本,分析了2011年8月乌梁素海水体总磷(TP)、总氮(TN)、氨氮(NH4--N)、硝氮(NO3--N)以及COD的空间浓度分布,构建并计算了个监测点的削减效率指数。结果显示:在水体由湖区北部向南部的流动过程中,乌梁素海对营养盐的削减效率指数呈现先增大后减小的非线性变化。营养盐削减效率最大和最小的区域分别在距离入湖口3km和出湖口3.5km附近。湖区西部对部分营养盐的削减效率较低,可能与该区域的回水地形有关,各监测点的削减效率受区域的物理、化学特性差异的影响而呈现复杂性。该研究的开展可为揭示乌梁素海湖泊水体富营养化控制和管理提供科学依据。

Spatial changes of nutrient reduction in the Wuliangsuhai Lake

As a large water-carrying lake,the Wuliangsuhai accepted a large amount of waste water from the Hetao Area.The lake turned out to be a eutrophic lake while decreased the concentration of nutrients.To reveal the processes and rules of nutrients removal in the Wuliangsu Lake,we collected 100 water samples and analyzed the concentration reduction index(CRI) of TP,TN,NH-4-N,NO-3-N and COD in the lake in August 2011.Results indicate that the CRI of nutrients descended nonlinearly from west to east during the flows of water.The largest and smallest CRI appeared in two regions apart from entry and export about 3.0.km and 3.5km,respectively.The reduction efficient points varied in different monitoring points with complicate physical and chemical factors involved.This study can provide scientific support for the water eutrophia control and management in the Wuliangsuhai Lake.