Effects of evapotranspiration and precipitation on dryness/wetness changes in China
Effects of evapotranspiration and precipitation on dryness/wetness changes in China
复制标题
蒸散量和降水量对中国干湿变化的影响
DOI：
10.1007/s00704-020-03336-8
复制
发表时间：
2020
影响因子：
3.4
通讯作者：
Wang Jinsong
中科院分区：
文献类型：
--
作者：
Wang Suping;Zhang Qiang;Yue Ping;Wang Jinsong
基于1960-2017年693个气象站的逐日气象资料，分析了中国旱涝趋势特征及其与参考作物蒸散量（ET 0）和降水变化的关系。结果表明，近58年来，我国西南半干旱半湿润区和湿润区呈现出明显的干旱化趋势，西北干旱区和南方湿润区呈现出明显的湿润化趋势。干旱和半干旱地区的干湿变化趋势对ET 0的变化敏感，湿润和半湿润地区的干湿变化趋势对降水敏感。ET 0和降水量对旱涝趋势的贡献存在显著的区域差异。在干旱区，除冬季外，ET 0的平均贡献大于降水的7%。由于风速降低和降水增加，ET 0降低，导致这些地区出现湿润趋势。在半干旱/半湿润地区，ET 0对干湿趋势的影响显著大于降水。春季ET 0的贡献比降水大21%左右，在年尺度上约大7%左右。由于气温上升和降水减少导致ET 0增加，该地区趋于干燥。在湿润地区，降水是湿润趋势的主导因素。在夏季和年尺度上，降水对SPEI的贡献比ET 0大4 ~ 10%，在冬季甚至完全控制SPEI的变化趋势。但在湿润地区，春季ET 0的贡献略大于降水的贡献，气温的显著升高导致ET 0的增加，并导致干燥的趋势。除降水减少外，蒸散量增加对干旱趋势的贡献相当，甚至大于旱季和干旱地区的降水。我们的研究结果表明，ET 0在全球变暖背景下的影响值得更多的关注，在未来的干湿或干旱的研究。
Based on daily meteorological data from 693 weather stations for the period 1960–2017, the characteristics of dryness/wetness trends and their relation with reference crop evapotranspiration (ET0) and precipitation changes were assessed in China. The results showed that the semi-arid/semi-humid areas and humid areas of southwestern China experienced a drying trend, while the arid areas in northwestern China and the humid areas in southern China became wetter over the past 58 years. The dryness/wetness trends were highly sensitive to the variability of ET0in the arid and semi-arid areas and to precipitation in the humid and semi-humid areas. Regional differences in the contributions of ET0and precipitation to the dryness/wetness trends were significant. In the arid areas, the average contribution of ET0was 7% larger than that of precipitation, except in winter. A decreased ET0due to a reduction in wind speed and the increase in precipitation led to a wetting trend in these areas. In the semi-arid/semi-humid areas, ET0had a significantly larger effect on the dryness/wetness trends than precipitation. Contribution of ET0was about 21% larger than that of precipitation in spring and about 7% larger at the annual timescale. Due to an increase in ET0because of rising temperature and decrease in precipitation, the areas tended to be drier. In humid areas, precipitation was the dominant factor for the wetting trends. Contribution of precipitation was about 4 to 10% larger than that of ET0in summer and at the annual timescale and even completely dominated the trend of SPEI in winter. However, contribution of ET0in spring was slightly larger than that of precipitation in the humid areas, and a significant increase in temperature led to an increase in ET0and resulted in a tendency of dryness. Aside from the reduction in precipitation, increased evapotranspiration had comparable contributions to the trends of dryness, even greater than that of precipitation in the drying season and in drying areas. Our findings suggested that the effects of ET0against the background of global warming deserve more attention in future studies of dryness/wetness or drought.