Chemical Characteristics And Genetic Mechanism Of Shallow Groundwater In Siziwang Banner,inner Mongolia

Siziwang banner is located in arid and semi-arid areas in the north of China.The frequent agricultural activities,mineral exploitation and groundwater exploitation in the banner have affected the groundwater in this area to a certain extent.The purpose of this paper is to analyze the chemical characteristics of groundwater in this area and its genetic mechanism,which has positive guiding significance for understanding the interaction between groundwater and surrounding environment and rational development of groundwater.This paper,by using 2015-2016 wet season of 194 water samples of groundwater,the quaternary unconsolidated rock pore water samples 57,cretaceous clastic rock fracture pore water sample 137,USES three Piper diagram,based on Kurt's type and the shu card Lev classification principles of hydrochemical classification notation,Schoeller figure,multivariate statistics,correlation analysis,Gibbs figure and ion ratio coefficient method such as water chemical characteristics and the cause analysis,the results show that the quaternary loose rocks are mainly low salinity of pore water of neutral-weak alkaline water,A small amount of groundwater is brackish water,and the overall water quality is good,but there are some water sample points with excessive water quality phenomenon;The groundwater salinity of cretaceous clastic rock fracture pore water is relatively high on the whole.Only a few of the groundwater is fresh water,and most of the groundwater is brackish water and salty water.The groundwater is generally neutral to slightly alkaline,and most of the water samples exceed the water chemical index.Pore water of quaternary loose rocks is dominated by HCO₃-Ca·Mg type,with dominant anions as HCO₃^-and dominant cations as Na⁺.Cretaceous clastic rock fracture pore water is dominated by SO₄-Ca·Mg type and SO₄·Cl-Na,with dominant anions as Cl^-and dominant cations as Na⁺.Based on the classification principles of kurlov's and shukarev's classification methods,the hydrochemical types in the study area can be divided into 53 types.Quaternary unconsolidated rock pore water chemistry class causes natural mechanism mainly for the water rock interaction and cation adsorption alternately,cretaceous clastic rock fissure water chemical genetic mechanism of natural mainly for evaporation and concentration and water rock interaction,cation adsorption,alternately by ion ratio coefficient method confirmed that the quaternary unconsolidated rock pore water and the cretaceous clastic rock fissure water are affected by human activities and cretaceous clastic rocks less contact between fissure water aquifer medium,aqueous medium relatively closed,so the water quality is worse.