Characteristics and prospective evaluation of natural mineral water resources in the Erhai lake basin

WANG Bo; ZHAO Li; CHEN Xiaomei; ZHU Guangyi; ZHANG Gaoyin

doi:10.11932/karst20240605

Abstract：The Erhai lake basin is an area with a beautiful ecological environment and important cultural and economic value in Southwestern China;therefore,in-depth studies on mineral water resources in this region hold far-reaching significance in ecology,environment,economy and society.This study is based on the project of the investigation of hydrogeological elements of typical wetland environment in the Erhai lake basin,located in northwest Yunnan.It systematically summarizes,organizes,and analyzes various factors,including landforms,stratigraphy and lithology,geological structure,climate,and water quality,based on extensive investigations and sampling tests.By examining the characteristics of mineral water resources,this study elucidates their water quality,quantity,and distribution patterns.Through a long-term evaluation,it forecasts the development potential and sustainable utilization prospects of these mineral water resources,thereby providing robust support for ecological protection,sustainable water resource utilization,economic development,and social stability in the Erhai lake basin. The mineral water resources in the basin encompass drinking mineral water containing both metasilicic acid and trace elements,and therapeutic mineral water.These resources are primarily distributed in a belt-like pattern across the western part of the basin,exhibiting higher abundance in the northwest and lower abundance in the southeast.They are more prevalent in mountainous areas and less so in the basin.These mineral water resources are typically located in regions with well-developed faults and folds,frequent variations in stratigraphic lithology,and a widespread presence of magmatic rocks.In terms of water quality characteristics,mineral water typically contains a high concentration of metasilicic acid.In areas with carbonate rocks,drinking mineral water often contains trace elements such as Sr and Zn.Conversely,in basalt regions,mineral water rich in metasilicic acid is more common.For therapeutic mineral water,both the concentration necessary for medical efficacy and the concentration required for classification as mineral water must meet or exceed three specific criteria.Based on the differences in the primary controlling factors of formation conditions-such as geological structure,topography,aquifer burial and distribution,and groundwater runoff circulation-the mineral water in the basin can be categorized into two types of genesis:fault-zone convection type and subsurface dissolution-filtration type.The fault-zone convection type constitutes 42%of the total and is characterized by deeper circulation,pressurization,higher water temperatures,and more stable dynamics.This type often yields high-quality therapeutic mineral water.In contrast,the subsurface dissolution-filtration type accounts for 58%and primarily produces drinking mineral water rich in metasilicic acid.This type is associated with simpler hydrogeological conditions,exhibiting characteristics such as shallower circulation depth,shorter cycles,and unstable dynamics.The Erhai lake basin is abundant in mineral water resources,which are currently underexploited,indicating significant potential for further development.Conducting research and analysis on the characteristics of these mineral water resources,performing long-term evaluations,and scientifically formulating protection and development strategies can help forecast the development potential and sustainable utilization prospects of mineral water resources.These efforts will contribute to the rational planning of the water resources development,help prevent over-exploitation,and ensure sustainable use.Furthermore,they will play a crucial role in maintaining the ecological balance of the basin,protecting biodiversity,and promoting the coordinated development of the regional economy and the environment.