Characteristics of groundwater resources and their reasonable development

Groundwater resources are of renewability and nonrenewability, with their occurence in a whole hydrologic system as a constituting part and their variability with time. The renewable resource, i.e., recharge resource, is a kind of sustainable water supply in theory, and the nonrenewable resource, i.e., storage resource is only for emergency use, not for sustainable use. Since groundwater resources occurs in an aquifer system as a constituting part, their evaluation should be carried out within the whole aquifer system or a hydrologic system, not within individual aquifers. Since the quantity of groundwater resources changes with time owing to the changes in land use, reevaluation of groundwater resources based on the conditions changing with time is needed. According to the concept of sustainable development, both sustainable water supply and protection of eco-environment are essential prerequisites for evaluation of groundwater resources. Multiple approaches to evaluation of groundwater resources are used in order to obtain satisfactory results. Exemplified by the North China Plain, the characteristics and reasonable development of groundwater resources are discussed in this paper.