Abstract:

Groundwater is the main water supply source in North China Plain (NCP), and atmospheric precipitation infiltration recharge is the main supply source of the groundwater in this area. Therefore, the studies on temporal and spatial changing features of climate in NCP are of great significance to further analyze the influences of climatic changes on groundwater resources. Based on 18 ground climatological stations in NCP in terms of daily climate observation data from 1951 to 2011, this paper analyzed the spatial-temporal evolution features of climate in NCP. The results showed that the minimum temperature of NCP in recent 60 years increases significantly; the maximum temperature is basically stable; and the mean temperature presents an obviously increasing trend. In the spatial distribution, it gradually decreases from southwest to northeast on the whole and gradually tends to increase from the coastal to inland. The precipitation owns a trend of overall gradual decrease and a trend of being weaker at first and then stronger from piedmont plain to coastal plain. Precipitation distribution characteristics are compared and analyzed in the typical lightest and heaviest rainfall years. The spatial distribution presents significant difference in these different rainfall years. Water surface evaporation shows a declining trend overall and it is more in south and north than in central region. NCP has a warming and drying development trend on the whole. Abrupt change mainly occurred in the middle of 1960s and the beginning of 1970s. The climatic change and human activities are two influential factors of groundwater resources. Effects of precipitation on groundwater will be further intensified in extreme climate condition. Measuring and distinguishing of the influences of climatic change and human activities on groundwater remain to be further explored.

Key words: North China Plain, climate change, precipitation, temperature, evaporation, groundwater