中国20世纪干旱化趋势分析

Study on Aridity Trend in China in 20th Century

采用东安格利亚大学气候研究中心的时间序列2.0气象数据集,利用Holdridge可能蒸散率干燥度计算方法,分析20世纪我国干燥度的动态变化。用GIS软件对其结果进行插值计算,并做出干燥度分布的数字化地图。分析结果表明:20世纪我国的湿润气候区面积减少严重,半湿润气候区面积有较大增加,干旱气候区面积增加也较显著,干旱化趋势明显。温度升高和降水量的减少导致了地表水分收支减小,不利于陆地表面的水分累积,是产生和加剧干旱的一个重要因素。

In this paper,the values of aridity index in China were calculated using the time series 2.0 climatic datasets from Climatic Research Unit of University of East Anglia and the Holdridge potential evapotranspiration method.On which the dynamic change of values of aridity index in China in the 20th century was analyzed.Moreover,the results were interpolated in GIS software,and then they were formed as the digital maps of AI distribution in China.The results show that there was a notable reduction of humid climate area in China in the 20th century,semi-humid climate area was enlarged considerably,dry climate area was enlarged significantly,and the drought trend was significant.Temperature increase and precipitation decrease in China leaded to a reduction of surface moisture and a disadvantage for moisture accumulation over land surface.These are the important factors of producing and aggravating ariditification.