Water resources play an important role in supporting the economic and social development of China. The impact of climate change on water resources has become a bottleneck in this process, especially for major projects, with surface water and groundwater systems experiencing considerable impacts. The annual natural recharge of fresh groundwater is 8840×10⁸ m³, which accounts for approximately 31% of the water resources. Groundwater is the most significant water source for many cities and energy bases, and it is also the main source acting as a buffer against extreme climate events caused by climate change. However, most of the groundwater in China buried deeply and unevenly, which increases the difficulty of investigating and exploiting this resource.This paper illustrates the general conditions of China water resources and hydrogeological hazards, such as karst sinkholes, surface subsidence, and soil salinization, caused by climate change, El Nino, La Nina, other climate events and human activities and presents the regulatory measures enacted to mitigate these issues in China.The China Geological Survey (CGS) has organized professional teams to investigate and evaluate groundwater resources and the environment since 1999. Based on these investigations, the total quantity, expected exploitable quantity and current exploited quantity of groundwater in whole China have been evaluated. In addition, an evaluation of the groundwater pollution caused by climate change throughout China and key areas has been conducted. At present, the CGS is conducting national groundwater monitoring projects and establishing regional engineering and technical measures for water resource exploitation and utilization.

The hydrogeochemical features of typical karst region in Western Thailand were discussed based on the high-resolution automatic hydrochemical monitor and karst spring water quality test data. The standard dissolution tablet method was employed to calculate dissolution rate of different lands and main characters and dynamic factors of Thailand karst growth were analyzed. Comparing with the typical karst spring region in the southwest China, karstic water of the Western Thailand has the features of high calcium (100-120 mg/L), high contents of bicarbonate ions (8.6-9.3 mmol/L) and high specific conductance (700-820 μs/cm); the dissolution quantity of soils in the dry season was between 28.95 mg/m²·d and 214.84 mg/m²·d; the annual dissolution quantity was twice-three times greater than that of Jinfo Mountain in Chongqing or Guangxi Mashan County peak cluster depressions, indicating that under the condition of tropical monsoon climate, the karst process in river catchment was significantly stronger than that of subtropical karst region in the southwest China.