乌梁素海湿地对营养盐的削减效率及其分区研究

基于乌梁素湖区20个监测点近2 a的监测数据，分析不同介质（水体、植物和底泥）对总氮和总磷的净化过程，构建削减效率指数，核算不同湖区对营养盐的削减效率，通过聚类分析划分削减区。结果显示:水体和植被中N和P营养盐浓度（含量）随着水体流动逐渐扩散降低，而底泥中营养盐分布没有明显规律，浓度最高点出现在距离入水口较远的东南部湖区。N和P营养盐在水体和植物间的分布呈正相关（N，R²=0.665，p < 0.05；P，R²=0.767，P < 0.01），而营养盐在底泥—水体，底泥—植物间的分布未发现明显的相关性。湖区依照营养盐削减效率可划分为2～4个削减区，不同削减区应采用不同控制手段。本研究可为乌梁素海湖泊水体富营养化控制和管理提供科学依据。

Reduction Efficiency and Partition of the Ulansuhai Lake

This study analyzed the reduction process of total nitrogen and total phosphorus in water, plants and sediment based on nearly 2-year monitoring data from 20 monitoring points in the Ulansuhai Lake. Reduction efficient index was screened to calculate reduction efficiencyof different regions of the lake. Cluster analysis was utilized to regionalize the lake. Results indicated the concentrations of N and P in water and aquatic plants reduced along with water flows; there was no obvious distribution rule with respect to the concentration in sediments and the concentration peak appeared in the southeast region of the lake. Nutrient concentrations between water and aquatic plants had the positive correlation (N, R²=0.565, p < 0.05; P, R²=0.867, P < 0.01) while there was no obvious correlation of nutrient concentrations between sediments and plants or sediment and water. According to the reduction efficiency, Ulansuhai Lake can be divided into 2 or 4 regions. Different measures should be taken to treat the eutrophic lake. The current research may provide scientific basis for eutrophication control and management of eutrophic lakes.