Geothermal Groundwater Tourism Resources

Under certain geologic conditions, geothermal groundwater influenced by the heat inside the Earth can have different temperatures. Geothermal groundwater can be classified into different types based on the use and temperature, but the standards vary in different countries. From the perspective of recuperation, Japan uses the categories of slightly warm water (25–34 °C), warm water (34–42 °C) and hot water (>42 °C). China currently uses the standard of 25 °C as the lower limit of hot water (according to China’s Geothermal Resource Temperature Classification) and categorises water into low-temperature hot water (25–40 °C), warm hot water (40–60 °C), hot water (60–90 °C) and superheated water (>90 °C). According to the geological processes and occurrence, geothermal water can be divided into (1) geothermal water related to volcanic and magma activity; (2) recirculated geothermal water related to fold and fault zones; and (3) subsidence basin-type geothermal groundwater. China has rich...