GRACE重力卫星探究我国华北地区陆地水储量变化

The variation of terrestrial water storage in north China based on GRACE gravity satellite

利用GRACE(gravity recovery and climate experiment)卫星2003-2013年资料分析了华北地区陆地水储量变化,并与同时间段的CPC(climate prediction center)、GLDAS(global land data assimilation system)水文模型进行比较,GRACE与CPC和GLDAS的相关系数分别为0.679、0.817,GRACE与GLDAS相关性更强。得出结论:2003-2013年华北地区陆地水减少,变化率为-1.8km^3/a,扣除地表水后,地下水变化率为-1.3km^3/a。其中,2003-2004年地下水有所增加,2005-2013年下降,2010年以后下降趋势变缓。GRACE反演与水文模型模拟结果显示,2006、2009年的等效水柱高(equivalent water height,EWH)均明显小于长期平均值,并且GRACE最值对应月份异常,对比国家统计局数据分析结果,这两年水资源总量、地表水资源量、地下水资源量处于低谷区,这与同年发生的自然灾害相对应。

The variation of terrestrial water storage from 2003 to 2013 was analyzed using GRACE(Gravity Recovery And Climate Experiment)satellite data and then compared with CPC(Climate Prediction Center),GLDAS(Global Land Data Assimilation System)hydrological models in North China.The correlation coefficients of GRACE,CPC and GLDAS are 0.679 and 0.817,respectively,while GRACE has a stronger correlation with GLDAS.The results showed that:terrestrial water storage and groundwater decreased at a rate of -1.8 km^3/a and-1.3 km^3/s from 2003 to 2013 after deducting surface water as a whole.It's worth noting that the variation of groundwater presented different stages:increased from 2003 to 2004 and declined from 2005 to 2013,the downward trend had slowed since 2010.GRACE and hydrological models showed that equivalent water height was significantly smaller than the long-term average in 2006 and 2009.The month corresponding to the GRACE maximum was unusual in the two years,compared with the results of the National Bureau of Statistics of China,the total water resources,surface water resources,and groundwater resources in the valley area,which corresponded to the natural disasters occurred in those two years.