华北平原地下水水位持续下降对大气边界层高度影响的初步研究

A preliminary study on the influence of declining groundwater level on the planetary boundary layer height in north china plain

利用GRACE重力卫星反演所得到的华北平原2003年~2015年的月均等效水高数据以及根据NCEP/NCAR再分析资料获取的华北平原大气边界层高度数据,对近13a来上午6时的边界层高度和等效水高的年均值、月均值以及季节均值进行相关性分析,同时也对边界层高度和地下水水位变化的一致性进行了初步分析.结果表明:近13a来上午6时的年均边界层高度和年均等效水高均呈现波动下降的特点,二者具有显著的线性相关性,R2为0.57;边界层高度对于地下水水位的变化响应具有一定滞后性,滞相关分析表明二者之间的滞后性在时间上可能表现为3个月.华北平原地下水水位持续下降,可能导致了华北区域大气边界层高度的下降,从而减弱了大气污染物在垂直方向上的扩散,减少了大气环境容量.因此,地下水水位下降可能是加重华北平原灰霾天气的一个重要因素之一,该研究为更全面研究我国灰霾的形成机理提供一个新的视角.

The effect of continual declined groundwater level on planetary boundary layer height was analyzed by using data, equivalent water height （EWH） and planetary boundary layer height （PBI.H） in North China Plain, from GRACE and reanalysis data and NCEP/NCAR in 2003-2015. Correlation analysis of annual, monthly and seasonal PBLH and EWH is carried out in past 13 years, along with the consistency verification between PBI.H and EWH. It shows that： both the PBLH and EWH at 6 a.m. are decreased in a fluctuation, and there is a significant linear correlation between the above two with the R2 of 0.57; there exists a lag in PBI.H for the response to groundwater level, which may be 3 months. The continual drop of groundwater level in North China Plain may lead to the lowing of PBLH, weakening of the pollutants diffusion in the vertical direction and further reduce atmospheric environmental capacity. Accordingly, the declining groundwater level may be one of important factor in aggravating the haze weather in North China plain, which provides a new perspective for demonstrate the for mation mechanism of a of China＇s haze.