STUDIES ON HYDROCHEMICAL CHARACTERISTICS AND FORMING MECHANISMS OF JIMO HOT SPRING GEOTHERMAL FIELD

The Jimo geothermal hot spring is an important pillar for local economy in the Qingdao region for years. The supply of hot water has gradually become insufficient with time, and many environment problems have appeared. In this paper, upon the basis of the study of regional geological background, hydrochemical and isotopic compositions of the geothermal water from the Jimo Hot Spring were systematically analyzed for the years of 2007, 2008 and 2014, in addition to the geochemistry of surrounding rocks. The research results show that the Jimo hot spring owes its origin to the unique structural conditions and excellent water storage conditions. Water is recharged from atmospheric precipitation. It goes to the deep where it is heated by deep crustal heat flow. Due to over-extraction of hot water since last decade, the geothermal water circulation rate of the hot spring has accelerated significantly. The main ions components such as Na⁺and Cl⁻, as well as the hydrogen and oxygen isotope compositions, show quite significant differences caused by multi-endmember mixing and water-rock interaction. In order to improve the management of the hot spring, it is suggested that long-term seasonal and interannual observations and hydrochemical simulation be established to provide scientific monitoring for the development and management of hot spring and geothermal resources.