Analysis And Study On The Evaluation Of The Quality Of Irrigation Water In Tupan City

In recent years, the quality of irrigation water in arid area is declining and soil trends to salinization gradually. Especially in the Turpan area of China.In there rainfall and surface water is scarce, while evaporation is dramas. In the process of the development of irrigated agriculture, some of the people use of saline water directly which improve soil salinization; some of them use improper irrigation method, drainage is not timely resulting in the underground water level rising, secondary salinization of soil, decrease in production capacity, resulting in the potential harm to the agricultural irrigation. So how in this arid region based on the analysis of the present situation of water quality and the historical changes of the irrigation water resources are scarce, the more reasonable use has become particularly important and key.In this paper, combined with the analysis of single factor analysis and water chemistry on the change of water quality and the potential impact of the correlation analysis research, use the matter element analysis method and fuzzy comprehensive evaluation method with two weight grade of Turpan irrigation water resources of the 2013-2014 and irrigation water resources of Turpan city in 1958 and the 1975-1985 historical data of Meiyao water. The results are as follows: matter element analysis method and fuzzy comprehensive evaluationmethod with two kinds of weight are all suitable for irrigation water quality evaluation of Turpan city. Taking the drought and saline situation into consideration, matter element analysis method contacts each data and regional data, which conforms to the actual situation of water quality in the region. Using the the fuzzy comprehensive evaluation method with the weigh of the reciprocal of mean, each index in the evaluation is more balanced, and the results are morecomprehensive and summary. By using the fuzzy comprehensive evaluation method with the weight of the maximum pollution hazard factors, it is easy to speculate that the potential problems of water quality.And its resauls and single index evaluation results are basically identical. Irrigation water of Turpan city in 1958 and 1975-1985 years was grade I water; which chemistry type is HCO3--Ca2+, belong to the weathering of rock types, and all in the Gibbs model.Anthropogenic influences on it are small. Based on the irrigation water of 2013-2014 in Turpan City, from space, the water quality of Dahe river, Hei river and Qiquan spring is Superior.The water quality of Taerlang is good.The water quality of downstream of Grape Valley and shengjinkou is not good;the water quality of downstream of Meiyao river and Meiyao river karez water quality is poorer. From the time point of view, the water quality of 3-5 month is poor. Especially in March, the quality of the Grape Valley, Meriyao water, Meiyao well water, karez water and Aydingkol lake water is poor, which is not suitable for agricultural irrigation. Compared with the historical data, water chemistry type changes, HCO3- and Ca2+ decrease and SO42- and Na+ increased significantly.In addition to the downstream of the Meiyaoriver which effected by evaporation crystallization obviously, the rest of the water is still controlled by rock weathering. In addition to the river, most of the rest of the water resources as the evaporation crystallization control action, and most of water resources has been in the Gibbs model of boundary, is influenced by human factors.In this paper, according to the analysis, a series of evaluation results and conclusion is given.The analysis of these changes may because of the rise of temperature in the recent 50 years in Turpan City, the development of the industry, the pollution of water resources.At last make reasonable suggestions.