统计降尺度方法对渭河流域气候要素的模拟及预估

Simulation and prediction of climatic elements in Weihe River basin using statistical downscaling method

利用渭河流域21个气象站点1960-2010年的逐月降水、气温、潜在蒸散和NCEP再分析资料,采用逐步回归的统计降尺度方法,建立了月序列的统计降尺度模型,并将模型应用于CMIP5中CanESM2模式下RCP4.5情景,产生了未来气候要素的变化情景,主要结论如下:1)该法对潜在蒸散的模拟效果最好,气温次之,降水最差.2)对未来气候要素的预估从时间变化上看,各时期月降水相对于基准期而言稍有减少,气温相差不大,潜在蒸散稍有增大.3)从空间变化上看,未来多年平均降水和潜在蒸散分布呈现出由东南向西北逐渐减少的趋势,而气温分布呈现出由南向北逐渐降低的趋势.

The statistical downscaling model based on monthly data series has been established using the monthly precipitation, temperature and potential evapotranspiration data at 21 meteorological stations in Weihe River basin and NCEP reanalysis data from 1960 to 2010; moreover the model is applied in CanESM2 mode and RCP4.5 scenario of CMIP5; so the future change of climatic elements is formed. The main results are as follows. （1）The potential evapotranspiration is simulated best by statistical downscal- ing, followed by the temperature, and the precipitation is worst. （2）From the perspective of temporal varia- tion,the prediction of future climatic elements change is analysed and compared with the baseline period; the monthly precipitation reduces slightly in the future; the temperature differs littlel; and the potential e- vapotranspiration increases a bit. （3）From the perspective of spatial variation, the future annual average precipitation and potential evapotranspiration shows a gradual decreasing trend from southeast to north west; and the temperature shows a gradual decreasing trend from south to north.