Water Environmental Quality Evaluation And Trend Analysis Of Huangjiahu Lake

As the important water forms and resources, urban lakes play an important role in the construction of urban landscape,the improvement of the ecological environment and the storage of the flood water. However, because of the over-exploitation of the lake resources, the function of the lake is seriously affected. The scientific evaluation and analysis of the water quality and the water quality trend should be essential for the management and sustainable utilization of the lakes. Huangjiahu Lake is the urban park lake which is located in the development district of Wuhan. This paper has carried out the following researchs on the Huangjiahu Lake:(1) This study made a survey of water quality(TN?TP?CODCr?CODMn?DO?NH3-N?pH) of Huangjiahu Lake(2013~2014).(2) The Huangjiahu Lake water quality status, spatial distribution and the trend of water quality were studied by single factor index, CCME-WQI, GIS technology. The result indicate that the water quality can not meet the requirements. The water quality index map and the water quality parameters thematic maps reflect that the water quality of the lake was falling into the marginal to poor category.(3) The 12 points(2, 8, 12, 13, 14, 17, 21, 29, 31, 32, 34, 35)were choose to be the monitoring points in the process of the optimal selection of the monitoring points based on the matter element analysis and hierarchical clustering analysis. Here the water quality data of the 12 points could tell the water quality status of the HuangjiahuLake.(4) The Kendall trend test analysis of water quality monitoring data(2009-2014) of Huangjiahu Lake indicated that the water quality was deteriorating. The TN, TP and NH3-N were the parameters that showe some degree of upward trend during the studied period. The NH3-N was the parameter that shows the greatest degree of upward trend(?=0.0032). There were no prominent trends in the parameters of CODCr, CODMn, DO obtained in this survey. Study also indicated that the slope estimate of the CCME-WQI was 3.37 units per year in other words. All of above means a decline of the general water quality of the lake in six years.(5) In addition, some measures include the control of fisheries, the construction of rainwater and sewage pipe network, the construction of biogas digesters, the recovery of lakeside zone and the control of agricultural non-point source were adopted to protect the Huangjiahu Lake based on the analysis of the functions and characteristics of each part of the lake.