Evaluation Of Groundwater Quality And Hydrogeochemical Simulation In The Naomaohu Basin Of Xinjiang

Naomaohu Basin, some100km north from Yiwu County, Hami Prefecture inXinjiang, belongs to temperate zone and arid region. Naomaohu Basin is an importantoil base, the coal chemical industry base and agricultural development region in HamiPrefecture. Further research on the hydrogeochemical characteristic,hydrogeochemical processes and the present condition of groundwater quality andgroundwater pollution in Naomaohu Basin is significant to the reasonable explorationand protection of groundwater resources.The paper collects24groundwater samples, including15phreatic water samplesand9confined water samples, which are from different places, and tests22waterquality indexes. Based on the hydrogeological conditions, this paper studieshydrogeochemical characteristic and hydrogeochemical processes. In addition, theoutliers are eliminated by Grubbs statistical method, the environment backgroundvalues of groundwater are obtained by applying SPSS statistical software, finallycomprehensive index method is used in groundwater (phreatic water and confinedwater) quality evaluation, and the pollution evaluation index method is introduced toassess comprehensively the groundwater(phreatic water and confined water)pollutionstatus in the study area. The results of this paper are as follows:1. The statistical results of main groundwater quality indexes show that: theaverage content of confined water is higher than the average content of phreatic water.2. The results of quality evaluation of phreatic water and confined water showthat: wells ofⅠ, Ⅱ, Ⅲ, Ⅳ and Ⅴ type in15phreatic water monitoring wells arerespectively1,11,0,3,0, which are6.7%,73.3%,0.0%,20.0%and0.0%of thesampling points respectively, and wells ofⅠ, Ⅱ, Ⅲ, Ⅳ and Ⅴ type in9confinedwater monitoring wells are respectively0,2,0,0,7, which are0.0%,22.2%,0.0%,0.0%and77.8%of the sampling points respectively.3. The results of pollution evaluation of phreatic water and confined water showthat the degree of pollution about phreatic water and confined water is not high, andthey are basically in natural state;93.3%of the sampling points of phreatic water are not contaminated,6.7%of the sampling points are slightly contaminated. As to theconfined water, all of the sampling points belong to non-contamination. Generallyspeaking, the contamination degree of confined groundwater is lighter than thecontamination degree of phreatic groundwater.4. The results of hydrogeochemical simulation in typical profile show that: thechemical characteristics of the phreatic water in the southeast of Naomaohu Basin ismainly controlled by dilution.