Research On Water Quality Prediction And Eco-Environmental Water Requirement Of The Hulun Lake Inflow Rivers

Taking Hulun Lake,Kelulun River and Ulson River as the research objects located in the arid and semi arid region in Inner Mongolia,I used the actual monitoring data of 2015 and the SPSS software as an analytical tool to analyze the Hulun Lake basin water environment quality, and to get the main impact indicators through principal component analysis,I aslo gave the 2016 tendency forecasting of the main control factors in the two rivers and the lake. According the analysis results, I found the water quantity was the key factor for water environment quality changing in Hulun Lake. Then using the monthly frequency method and Montana method, I calculated the ecological water requirement. The main conclusions are drawed as follows:(1) Hulun Lake water and two rivers water quality indicators were analysis through principal component, and three main components, represented the original eight water quality factors. In the lake, the first principal components stood for nutrient pollution (contribution rate was 29.995%); the second principal component reflected the lake water physical environment and salinization(26.05%); the contribution of the three main components(14.77%) was closed to pH value and suspended solids (SS).In the rivers, the first principal contribution component(39.76%) reflected the saline pollution; the second (29.42%) reflected nutrient pollution; the third (13.38%) reflected riverriver habitat state.(2) Using grey model GM (1,1) to analysis and forecast the physicochemical parameters in Ulson River and Kelulun River, based on the GM (1,1) model, including 8 parameters, (pH, TDS, TN, TP, Sal, EC, DO, SS), this study has given the trend prediction in 2016 of the main control factors in two rivers and lakes. The results showed that the salinization pollution reduced in Hulun Lake water and nutrient pollution is exacerbate; the physicochemical parameters in rivers had the similar changing in lake water, pH, TDS, Sal, EC, DO, SS were decreased, and TN, TP were increased.(3) River ecological water demand (Minimum, suitable and ideal flow) of Urxun and Kelulun River were calculated by Montana method and monthly frequency calculation. The calculation results show that the monthly frequency method result was more accurate and stricter. So, we suggest to using the monthly frequency calculation to calculate the ecological water requirement and using the Montana method for inspection.According to the analysis, the environmental protection work of Hulun Lake should not only focus on water quantity management and protection, but also take into account the river water quality. It is better to accomplish comprehensively the arduous tasks to maintain sustainable development of Hulun Lake.