Hydrochemical and isotopic characteristics,changes and controlling factors of waters in the Yulong Snow Mountain-Lijiang area,China
The hydrochemical and isotopic compositions of water are controlled by natural and anthropogenic factors,therefore,it is of great significance to study the hydrochemical and isotopic compositions,changes and contributing factors for the rational utilization and scientific management of water resources within a watershed.Hydrochemistry,water(8D/818O-H2O)and carbon(δ13C-DIC)isotope samples from surface-groundwater in the Yulong Snow Mountains-Lijiang area,China,were analyzed to reveal the spatial evolution of the above indicators along the water flow direction,to compare the changes of water chemical compositions between 2005 and 2021,and to explore the spatio-temporal differences of regional water environment affected by human activities.Results showed that:(1)In the basin,surface water and groundwater were mainly recharged by local atmospheric precipitation and glacier-snow meltwater,and the water chemistry types were mainly Ca·Mg-HCO3 and Ca-HCO3,while the concentrations of Na+,K+,Cl-and SO42-increased in some wells due to human activities;(2)Under the influence of natural processes and human activities,δD/δ18O-H2O values increased along the direction of the surface-groundwater flow,while the value of 813C-DIC decreased.Concentrations of Na+,K+,Cl-and SO42-increased significantly after water flows through the main urban area;(3)Water quality of the Yuhe River was reduced from class Ⅲ to class Ⅳ(NH4+exceeded the standard)after the river flows through the Dayan ancient town,and significant negative correlation between Na++K+and δ13C-DIC,Cl-+SO42-and δ13C-DIC occurred in wells from the ancient town,which revealed the negative impact of tourism activities on the water environment;and(4)Compared with 2005,the growth rates of Na+,K+,Cl-and SO42-concentrations in the Yanggong River,which were fed by urban sewage and wastewater,were greater than those of Lashi Lake,Yufengsi Spring and Tuanshan Reservoir waters.Our study revealed that human activities had a certain negative impact on the water environment in the Yulong Snow Mountain-Lijiang area,which provided basic data for water resources protection in the river basin and also confirmed that the combination of isotopes and water chemistry is an important means to study the water environment change and the contributing factors.
hydrochemistrydeuterium and oxygen isotopecarbon isotopekarst groundwaterYulong Snow Mountain-Lijiang area
万方数据
维普
