Variations in precipitation extremes in the arid and semi-arid regions of China
Variations in precipitation extremes in the arid and semi-arid regions of China
复制标题
中国干旱半干旱地区极端降水变化
DOI：
10.1002/joc.6884
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Ma Yi
中科院分区：
文献类型：
--
作者：
Xu Lu;Zheng Chaolei;Ma Yi
据预测，降水状况将转变为更极端的模式，其特点是强降雨事件和更长的干旱间隔。极端降水的时空变化可能会对当地生态系统产生重大影响，特别是在干旱和半干旱地区。本研究调查了1960年至2018年中国干旱半干旱地区极端降水指数的变化。空间自相关分析也被用来评估研究区域内的空间自相关性。降水强度总体呈增加趋势，但低海拔半干旱地区的大部分站点变化趋势不明显。频率指数总体上呈现连续干旱日数减少的趋势，干旱和高海拔半干旱地区降水日数增加的趋势，表明干旱和高海拔半干旱地区正在变湿。仍有降水强度和频率下降的信号，如来自低海拔半干旱地区的站点连续干旱日数增加的趋势，这意味着在小空间尺度上干旱风险增加的可能性。全球Moran‘s I值表明，低海拔半干旱地区这一趋势具有较高的空间自相关性。当地的Moran‘s I表明，干旱地区有湿润趋势的站点数量远远多于半干旱地区。这些观测结果表明，中国干旱和半干旱地区的极端降水正变得更加均匀。因此，本研究可为政策制定者和利益相关者制定干旱区水资源和生态系统管理战略提供有益的参考。
Precipitation regimes have been predicted to shift to more extreme patterns that are characterized by heavy rainfall events and longer dry intervals. Spatiotemporal variation of precipitation extremes may significantly influence the local ecosystem, especially in the arid and semi-arid regions. This study investigated the variations in extreme precipitation indices across the arid and semiarid land of China from 1960 to 2018. Spatial autocorrelation analysis was also conducted to evaluate spatial autocorrelations within the study area. There was generally an increasing trend of precipitation intensity, however, most stations in the low-altitude semi-arid regions showed non-significant trend. The frequency indices generally showed a decreasing trend in consecutive dry days, and an increasing trend in precipitation days in the arid land and high-altitude semi-arid regions, suggesting that the arid and high-altitude semi-arid regions are becoming wetter. Signals of decreasing precipitation intensity and frequency were still found, such as increasing trends in consecutive dry days in the stations from the low-altitude semi-arid regions, implying the possibility of increased drought risk at small spatial scale. The global Moran's I values indicated that the spatial autocorrelation of the trend in the low-altitude semi-arid region is high. The local Moran's I showed that the number of stations with wetting trend in the arid region were much higher than that in the semi-arid regions. These observations imply that the precipitation extremes in the arid and semi-arid regions of China are becoming more homogeneous. Hence, this study can serve as a useful reference to the policymakers and stakeholders for framing water resource and ecosystem management strategies in arid regions.