Groundwater system division and compilation of Groundwater Resources Map of Asia

Based on landform, climate, river system, geological structure and hydrogeological structure and from the perspective of systematology, the groundwater system of Asia can be divided into 36 secondary groundwater systems under 11 primary ones by the intercontinental scale. A scientific evaluation of groundwater resources in Asia can be secured using water balance method and runoff modulus method through water circulating analysis and feature study of groundwater system on the basis of groundwater system division of Asia. With natural recharge (runoff) modulus (104m3/km2?a), the total amount of water resources and those available for exploitation of primary groundwater system can be evaluated-continuous aquifers in plains and basins contain 242.465×109 m3/a of water, 169.725×109 m3/a of which is recoverable; discrete aquifers contain 186.695×109 m3/a, 130.686×109 m3/a of which is available for exploitation; other scattered aquifers contain 38.614×109 m3/a, 27.029×109 m3/a of which could be exploited. In total, there is 467.774×109 m3/a of groundwater with 327.440×109 m3/a recoverable. The groundwater map of Asia is compiled according to groundwater system division, evaluation of the total amount and aquifer types to reflect the macro features of groundwater resources in Asia, laying a scientific foundation for exploitation and management of water resources here and for avoiding disputes over groundwater resources and environment among Asian countries.