扎龙湿地水体的富营养化特征及综合评价

Trophic state of Zhalong Wetland and the comprehensive assessment

通过野外调查和室内分析,探讨了近年扎龙湿地的水体富营养化特征及其发展趋势。结果表明扎龙湿地的水质富营养化严重:各项指标(除CODMn外)的含量最高的时期都为Ⅴ级水质标准;另外,湿地的水质在空间上存在明显的差异。农业活动较频繁的地区的水质污染最重,扎龙湿地富裕以及林甸地区所属的湿地边缘的CODMn高达200ug/L,TP含量最高超过1000ug/L。应用幂函数加和型(EI)以及改进型营养状态指数模型(TSIm)对扎龙湿地水体富营养化进行综合评价表明,两种模型评价的结果存在模型的线性相关关系。扎龙湿地水体富营养化程度较高,大部分属于(重)富营养化甚至达到极富营养化程度,并且近20年来扎龙湿地水体富营养化程度整体上呈现恶化的趋势。

Based on in-situ observation and analysis in laboratory,the level of water trophic state and its trend in recent decades in Zhalong wetland were discussed.Results showed that Zhalong was a vulnerable zone in west Songnein Plain,which has been showing a trend of degradation.The wetland showed a severe level on eutrophication,with Ⅴ levels in most water region for most indices index except CODMn of Ⅰlevel.The agricultural zone showed the severest water pollution,i.e.The peak concentration of TP and TN even reached 200 ug/L and 1000 ug/L,which were larger than Ⅴ level of 12 folds and 15 folds respectively.The most indices had appeared to be ＂rich＂ trophic state.A power function of weighted sums（EI） and a revised Carlson index formula（TSIm） for evaluation of the eutrophication level of lakes were used to evaluate water trophic state in recent decades.The assessment results proved that EI existed a good linear relation with TSIm mode.The most water bodies in current in Zhalong wetland were reached to ＂rich＂ even ＂severe rich＂ state for which the level of EI appeared to increase over time.