Evaluation of Water Quality Improvement in Wenyuhe River Based on the Analysis of Diversity of Macro-zooplankton

The analysis of diversity index of macro-zooplankton in Wenyuhe River with Shannnon-Weaver diversity index(H'),zooplankton species and sensitive species from May 2010 to February 2011 was carried out after the demonstration project.The amount of zooplankton in Roma East Lake where the demonstration project was running increased evidently,and the number of sensitive species rose.Shannon-Weaver diversity index(H') changed gradually from 0.650 1(serious pollution type)in May to 2.134 2(medium pollution of β type) in October,and it showed the rule of seasonal change.Though H' of Weigou Bridge downstream increased due to H' of Roma East Lake,which showed the same trend as Roma East Lake,the water quality was poor due to the water pollution of Qinghe River.H' of Beiguan Brake downstream of Weigou Bridge decreased evidently.The results suggested that the artificial demonstration project of Roma East Lake had positive effects on the improvement of water quality.However,some other measures must be taken to control the pollution source to realize the targets of overall improvement of water quality in Wenyuhe River.