Hydrologic geochemistry characteristics and hot water sources of hot spring in Lalong Lake, Baiyu County, Sichuan Province

The hot spring water in Lalong Lake is located in the Lalong Lake National Wetland Park in Baiyu County, and its development is conducive to improving tourism quality and environmental protection. This paper collects two sets of hot spring water samples and analyzes the hydrogeochemical characteristics, supply sources, thermal storage temperature, and circulation depth of the hot spring water in Lalong Lake using research methods such as hydrochemistry, isotopes, and geothermal temperature scales. The research shows that the natural temperature of hot spring water in Lalong Lake is 71-73 ℃, with a pH value is 6.35-6.22, and a TDS is 916-957 mg/L. The hydrochemical type is HCO₃⁻—Na, which belongs to immature water. The main sources of replenishment are atmospheric precipitation and melting ice and snow at elevations of 4 539-4 702 m on the north and east sides. Using the silicon dioxide geothermal temperature scale method and the graphical method of silicon-enthalpy, the thermal storage temperature after mixing shallow cold water is calculated to be 75.3-120.9 ℃, the deep thermal storage temperature is 154.2-194.4 ℃, the cold water mixing ratio is 66.44-73.12%, the deep circulation depth is 3 072-3 876 m, the thermal storage temperature after mixing shallow cold water is about 75.3-120.9 ℃, and the circulation depth is 1 496-2 406 m. The results of this research are expected to provide strong support for the development and utilization of hot spring resources in Lalong Lake.