Characteristics And Mechanism Of Salt Pollution Of Groundwater In Alluvial Fan Of Golmud River

The impact of human activities on groundwater is directly endangered the rational allocation of regional groundwater resources and future water exploitation.This paper summarizes the research methods of characteristics of groundwater pollution at home and abroad.Taking the alluvial fan of Golmud River as an example,the evaluation of pollution and water quality to identify current water quality status,and the characteristics of salt pollution of groundwater are identified by the screening of major pollution indicators.The factor analysis method was used to quantitatively evaluate the groundwater salt pollution in the study area.On that basis,from the point of view of water chemistry and multivariate statistics,the groundwater salt pollution mechanism in the study area was discussed.Followings are the conclusions of this research:?1?The results of water quality and pollution assessment showed that the groundwater quality in the study area was generally poor,with 34.4%of water samples from class IV,31.3%of water samples from class V,and higher rates of over-standard dissolved salt indicators.The degree of groundwater pollution was generally light.Among the 32 water samples involved in the assessment,mild degree pollution accounted for 25%,medium degree pollution accounted for 9.4%,and heavy degree pollution accounted for 9.4%.The heavy degree pollution contribution indicators were TDS and sodium.Chloride,TFe,total hardness,sodium,and TDS are the major pollution indicators in the groundwater in this region,and the salt pollution is a typical characteristics.?2?According to the quantitative evaluatio n results of groundwater salt pollution in the study area,the groundwater pollution degree is generally lighter,and the polluted area is mainly distributed in the east of Golmud River.The medium degree and heavy degree polluted areas accounted for 1.3%and 3.8%of the study area,which were mainly distributed in the east-farm of Golmud.The unpolluted and suspected pollution areas accounted for 56.5%and 26.8%of the study area respectively and mainly located in the area near the Golmud River and the regions with low human activity.?3?There are 6 types of hydrochemistry in the study area.The majority types of geochemistry of HCO₃·Cl-Na reflected the characteristics of the original water in the region.The hydrochemistry anomalies and the highly influential groundwater are mainly distributed in Golmud and east-farm regions.The types of hydrochemistry in the east of Golmud River are complex,and the SO₄^2-is the main anion such as SO₄·Cl-Na type water and HCO₃·SO₄-Na type water.The significant cause of salt pollution of groundwater and hydrochemistry anomalies is the intense human activity in the region.?4?The result of the analysis of mechanism of groundwater salt pollution in the region shows that the highly influential groundwater,which is greatly affected by human activities,is mainly distributed in the east of the Golmud River.The industrial,agricultural,production and other human activities have a significant effect on salt content increasing and hydrochemistry anomalies in groundwater.On t he one hand,it is caused by the direct input of salt from various sources of pollution,and on the other hand,it is affected by the extensive irrigation of the area to the salt leaching of the aeration zone and the rise of the groundwater level.