Groundwater and Its Association with Sustainability of Agriculture in the N~rth China Plain

During 1981–2000 annual precipitation decreased in the North China Plain (NCP), based on monthly data from 20 meteorological stations. Groundwater tables in the lower reach remained relatively stable, with a seasonal fluctuation of approximately ± m, while it decreased roughly 1 m year⁻¹ in the piedmonst of the plain, mainly due tooverpumping of groundwater and reducing precipitation. Diversions from the Yellow River contributed to this spatial disparity, and three different temporal patterns of groundwater table change were identified in the lower reach. Groundwater resources play an important role in water supply for irrigation and domestic water use, especially in extreme years of drought, and it is thus a major factor, affecting the sustainability of agriculture in the NCP.