华北平原气候时空演变特征

摘要

Groundwater is the main water supply source in North China Plain (NCP),and atmospheric precipi-tation 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 influ-ences 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 signi-ficantly;the maximum temperature is basically stable;and the mean temperature presents an obviously increa-sing trend.In the spatial distribution,it gradually decreases from southwest to northeast on the whole and gradu-ally 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 distribu-tion 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 develop-ment 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 precipi-tation 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.%地下水是华北平原主要的供水水源，大气降水入渗补给又是该区地下水的主要补给，因此研究气候时空演变特征对于深入剖析气候变化对其地下水资源的影响具有重要意义。依据中国18个地面气候站1951—2011年逐日气候观测资料，剖析华北平原气候时空演变特征。结果表明：华北平原近60年最低气温显著升高，最高气温基本稳定，平均气温明显升高；空间上呈由西南向东北逐渐降低、由沿海向内陆增高的趋势。降水量总体呈逐渐减少趋势，空间上由山前向滨海逐渐减弱后增强；对比分析典型极端丰枯水年的降水分布特征，不同降水年空间分布差异显著。水面蒸发量整体呈下降趋势，空间上南、北部大于中部。华北平原气候总体向暖干化方向发展，两次突变主要发生在20世纪60年代中期和70年代初。气候变化和人类活动是影响地下水资源的两个重要因素，极端气候则加强了对地下水的影响。因此，定量区分气候变化与人类活动对地下水的影响是有待进一步深入探讨的问题。