An analysis of deep groundwater and its utilization

Deep groundwater is defined as an unusual groundwater with small amount of recharge, slow renewal speed, long recharge cycle as well as little impact by climate fluctuations. Deep groundwater formed in geological historic periods with special climate conditions. Because most of the deep groundwater is confined, it is also called deep confined water. The experts from home and abroad have different viewpoints about the deep groundwater occrring in large sediment basins, including the formation mechanism, transport characteristics and availability, and the focus of the disputes is the hydraulic continuity. However, most of the specialists accept the point of view of hydraulic continuity. While some of the experts argue against the exploitation of deep groundwater. The long history of hundreds of years of the utilization of deep groundwater proves that the deep groundwater is allowed to be exploited, and the deep groundwater becomes the primary source of water supply in some of the arid and semiarid regions or countries. Exploitation of deep groundwater is mainly extracting the reserves. The allowable exploitation limit of deep groundwater depends on the allowable consuming reserves, and limit indicators usually are environmentally geological disasters (e. g., land subsidence). The exploitation strategies for deep groundwater are either long-term development or choosing substitutable resolutions. If choosing the former, it is necessary that the deep groundwater is exploited according to the stages and layers and enough time is needed to renew the water.