Xintian County In Karst Groundwater Hydrogeochemical And Isotopic Features

To realize the sustainable utilization of karst water resources in Xintian county,Hunan province,To maximize the economic benefit of strontium mineral water resources.In this article,through field test,sampling and indoor laboratory analysis method,to obtain relevant water chemical and isotopic data,by using the theory of groundwater system,hydrogeochemical analysis,combined the theory and method of environmental isotope tracer,discuss the water chemical characteristics and evolution of karst groundwater in the study area,it is concluded that the main results were as follows:The pH,TDS and hardness of karst groundwater in the strontium-rich region are greater than that of the karst groundwater in the non-rich strontium region,and the numerical dispersion degree is large.According to three piper diagram shows that 50non-rich strontium water points were all HCO₃-Ca types,and 69 percent of the water in the 22 strontium-rich water spots were HCO₃-Ca,23%HCO₃-Na,HCO₃-Mg and SO₄-Ca each accounting for 4%.The controlled mechanism of water chemistry in karst groundwater is rock weathering,which is influenced by the evolution of water filtration water in karst area.Rich strontium area only natural carbonate formation of karst water chemical composition,a small number of other acids were involved in the interaction of water rocks in the non-rich strontium region,and the preliminary analysis showed that other acids in the developed surface waters were involved in the dissolution process of the point soluble rocks.The hydrodynamic conditions of rich strontium area are weaker than that of non-strontium region.In the process of evolution,the regional karst groundwater has been alternately adsorbed by cationic ions,and the accumulation process of soluble salt has been developed.Through field investigation and analysis,She Tianqiao group formation of high abundance of strontium content and external a series of geological and hydrogeological conditions for the combination of regional formation of Sr mineral water laid the foundation.According to the multivariate statistical analysis,the formation of main negative and cationic ions in karst groundwater is closely related to regional stratigraphic lithology and human activities.The supply source of regional surface and groundwater resources is atmospheric precipitation,and the supply source is affected by the evaporation effect.The evaporation rate of seawater in the water vapor source area of the local precipitation is faster and the evaporation is stronger,and the air humidity is relatively low.The recharge elevation of karst groundwater in the Xintian river valley area is 164.5²29.3m,and the mean value is 198.5m,which is mainly distributed in the third section of the regional topography.Regional karst groundwater is modern water,with age less than 5¹0 years.Preliminary estimates,The natural supply quantity of strontium-rich mineral water,the natural excretion and the storage capacity are 4305.2×10⁴m³/a,362×10⁴m³/a,95040×10⁴m³,the annual replenishment quantity of humid year,the normal annual replenishment and the annual supply of drought are 4825.5×10⁴m³/a,4253.2×10⁴m³/a,3722.1×10⁴m³/a.The water quality level is 1.15⁴.83,the average grade is 2.59,and the overall water quality is relatively good.