气候变化对北京地下水资源的影响分析

Analysis of the Influence of Climate Change on Groundwater Resources in Beijing

总结了北京地下水资源概况,对近60 a来北京气温、降水、蒸发的变化特征进行了分析。结果表明:北京气温在波动中增暖,增幅约为0.08℃/a,而年降水量表现为下降趋势,平均变幅为-3.45 mm/a;年总水面蒸发量表现为明显的下降趋势,平均变幅为-8.04 mm/a。降水减少加之超量开采给地下水资源带来不利影响,导致地下水位持续下降,局部浅层含水层疏干,1999-2013年,第四系地下水累计亏损量达65.82亿m3,年均亏损量4.39亿m3,地下水水质也随之变差。平原区地下水蒸发量由1960-1980年的年均4.95亿m3/a,降至2001年以来的年均0.44亿m3/a。气温对地下水的影响是间接和微弱的。

The general situation of groundwater resources in Beijing is summarized in this paper, the changes of temperature, precipitation and evaporation characteristics in nearly six decades are analyzed. The results show that the temperature increases with fluctuation with a mean increment of 0.08℃/a, the annual precipitation gradually decreases with a mean rate of -3.45 mm/a. The amount of evaporation on surface water decreases with a mean rate of -8.04 mm/a. Precipitation decrease and groundwater overdraft bring adverse effects, leading to continually deseease of groundwater level and dewatering of some shallow aquifers. Depletion of groundwater storage is up to 65.82×10s m3 from 1991 to 2013, about 4.39×10s m3/a year on average. Groundwater quality becomes poor with the change. Annual mean evaporation of groundwater is 4.95×10s m3/a from 1960 to 1980, which reduces to 0.44×10s m3/a later in 2001. The influence of temperature on groundwater is indirect and weak.