Groundwater Quality Evaluation And Evolution Law Of Typical Rich Water Area In Qingdao

Qingdao is one of the cities with serious water shortage in China,because the development of social economy and the growing demand for industrial water,coupled with excessive exploitation of groundwater in recent years,Groundwater quality is deteriorating,and seawater intrusion,groundwater in Qingdao is facing serious water quality problems.Therefore,to carry out the research work of groundwater environment in Qingdao city have a great significance for the control and protection of groundwater and the rational development and utilization of groundwater.Based on the analysis of Qingdao City,Dagu River,the Yanghe River,Baishahe-ink River,Baimahe-Geely River four typical rich areas on the hydrogeological conditions,firstly,the evaluation factors were selected according to the characteristics of groundwater pollution in Qingdao and other typical areas.Then,the evaluation results of three methods,Nemero comprehensive pollution index method,fuzzy comprehensive evaluation method and physical element extension method were compared and analyzed,then combined with the groundwater environment of typical areas.Last,selecting the matter-element extension method to evaluate and analyzing the groundwater environment quality of four typical areas in Qingdao.In addition,the temporal and spatial evolution law of groundwater environment in four typical areas of Qingdao city was studied.The spatial evolution mainly from two aspects of each water rich chloride of the spatial distribution of total hardness,TDS,chloride,and the type of groundwater.The time evolution mainly from years of variation curve of each monitoring point in typical area of chloride ion,total hardness and salinity content to analyze.The main conclusions including:（1）According to the statistical distribution characteristics of groundwater chemical composition and the characteristics of groundwater pollution in typical areas,7 factors,such as chloride,sulfate,fluoride,nitrite,nitrate,total hardness and salinity,were selected as evaluation factors for groundwater environmental quality assessment in typical areas of Qingdao.（2）Nemero’s comprehensive pollution index method,fuzzy comprehensive evaluation method and matter element extension method are compared with the three methods.The matter element extension method is more suitable for the evaluation of water environmental quality in typical areas of Qingdao.（3）The results of groundwater environmental quality evaluation in four typical areas show that the quality of groundwater environment in Qingdao is good.Qingdao city underground water quality class II water quality accounted for 15%,accounting for 59%,accounting for 12%of class III water quality,IV water quality accounted for 5%,grade V accounted for 9%;better than grade III water quality（including grade III.）the total survey86%,worse than grade III water quality of groundwater in Qingdao city accounted for 14%.The good quality of the environment.（4）The spatial variation of chlorine ion,total hardness and salinity in each rich water area is the same,and the spatial distribution of hydrochemical types is more complex.The content of chlorine ion,total hardness and salinity from upstream to downstream of each rich water area is increasing gradually.The main types of groundwater chemistry in the Dagu river rich water area are HCO₃·Cl-Na·Ca、HCO₃·Cl-Ca·Na.Baishahe River-ink rich groundwater chemical type water area is mainly Cl·HCO₃-Na·Ca、Cl·HCO₃·SO₄-Na·Ca.The groundwater in the water rich area of the Yanghe River is mainly composed of HCO₃-Na、Cl·SO₄·HCO₃-Ca·Mg、HCO₃·Cl-Ca·Na.Baimahe Geely River groundwater mainly in HCO₃-Na、Cl-Na.（5）Since 90s,the Dagu river water rich and water rich groundwater in the Yanghe River basically stable chlorine ion content had no obvious change,Baishahe River ink-rich area decreased,water rich Baimahe River-Geely increases.Dagu river water rich area and river-rich water groundwater total hardness of Jilihe increased,Baishahe river water and ink-rich water rich area in the Yanghe River overall downward trend.Dagu river water rich area and the rich water-ink River groundwater is mainly freshwater and brackish water,the Yanghe River water rich area and river-Jili river water rich area salinity water is smaller,lighter,but the four typical areas of water are salty trend.