Hydrochemical Characterization,Controlling Factors and Water Quality of Surface Water in Shandong Province,North China

In this study,90 surface water samples were collected from Shandong Province(SDP)in the dry and wet seasons and analyzed using statistical analysis,hydrochemical methods and water quality index(WQI).The content of main ions showed seasonal variations,with a higher average value in the dry season than in the wet season.Sampling points exhibiting high contents of the main chemical components were mainly distributed in areas southwest of SDP,north of Weifang,and around Jinan.The saturation index of carbonate minerals was greater than zero,while that of evaporite minerals was less than zero.The hydrochemical characteristics of surface water are mainly dominated by rock weathering as well as cation exchange.In addition,surface water in SDP has significantly been affected by anthropogenic factors.Most of the surface water could be classified as weakly alkaline soft-fresh water,with the hydrochemical types of SO_(4)·Cl-Ca·Mg and SO_(4)·Cl-Na.In terms of WQI,47.88% and 37.88% of the water samples in SDP were classified as poor water in the dry and wet seasons,respectively.On the whole,the water quality is higher in the wet season than in the dry season,and surface water in SDP is generally suitable for agricultural irrigation.

Hydrochemical insights on the signatures and genesis of water resources in a high-altitude city on the Qinghai-Xizang Plateau, South-west China

Water resources have crucial implications for the steady development of the urban social economy.This study investigated the hydrochemical signatures and genesis of water resources in the urban area of Lhasa City(UALC).To this end,several analyses,such as ion ratio analysis and correlation analysis,were performed by comprehensively applying mathematical statistics and integrated hydrochemical methods.The results show relatively low concentrations of major ions in the groundwater and surface water(GSW)of the UALC.The primary anions and cations are HCO3-and Ca2+,reflecting the HCOg-Ca water type.Nevertheless,groundwater exhibits higher concentrations of key chemical components compared to surface water.GsW are weakly alkaline,with pH values of 7.78 and 7.61,respectively,and they have low salinity with average concentrations of total dissolved solids being 190.74 and 112.17 mg/L,respectively.Anthropogenic inputs have minimal influence on the hydrochemical features of GSw,whereas rock weathering is the dominant controlling factor.Furthermore,cation exchange.is a significant hydrogeochemical.process influencing their hydrochemical features.According to the isotope analysis(H and 180),the primary source of recharge for GSW is atmospheric precipitation,with some input from melted ice and snow.Moreover,GSW samples from the UALC show relatively similar 2H and 18O isotopic compositions,indicating the existence of a discernible hydraulic connection linking the two water sources.The research findings can serve as a valuable scientific reference and foundation for the sustainable development,effective utilization,and proper safeguarding of regional water resources in high-altitude areas.