On the uniformity of rainfall distribution over India
On the uniformity of rainfall distribution over India
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DOI：
10.1016/j.jhydrol.2019.124017
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发表时间：
2019-11-01
影响因子：
6.4
通讯作者：
Mujumdar, P. P.
中科院分区：
文献类型：
--
作者：
Dey, Pankaj;Mujumdar, P. P.
了解高强度和低强度降雨的时间分布、时间、频率和数量对气候变暖的响应在水资源管理中具有重要意义。本文利用相对熵研究了印度降雨量分布的空间变异性和均匀性变化。大气温度的时间趋势可以改变高强度和低强度降雨事件的频率和数量，从而影响降雨分布的均匀性。根据年平均气温的时间趋势，本研究分为1951-1980年和1981-2010年两个时间段。研究了降雨均匀度和高、低强度降雨事件对年平均气温的敏感性以及它们之间的相关程度。降雨量分布的均匀性表现出明显的空间变异性。印度各地的降雨量和降雨期都发生了重大变化。与遥远的过去相比，最近在更大的空中范围内观察到降雨均匀度和低降雨强度之间的显著联系。结果表明，气温升高改变了高强度和低强度降雨事件，从而改变了降水分布的均匀性。降雨均匀度与高强度和低强度降雨之间的相关强度在区域上是不同的，这可能是由于区域依赖的土壤水分-降水反馈所致。
Understanding response of temporal distribution, timing, frequency and amount of high and low intensity rainfall to warming is important in water resources management. In this paper, Relative Entropy is used to investigate the spatial variability and change in uniformity of rainfall distribution over India. Temporal trends in atmospheric temperature can alter the frequency and amount of high and low intensity rainfall events, which influence the uniformity of rainfall distribution. The study is divided into two time periods, 1951-1980 and 1981-2010 based on time trend in annual mean temperature. The sensitivity of rainfall uniformity and high and low intensity rainfall events to annual mean temperature and the degree of coherence between them are investigated. The uniformity of rainfall distribution shows a significant spatial variability. Significant changes are observed in both the amount and timing of rainfall across India. A significant association between rainfall uniformity and low intensity of rainfall is observed in the recent past over a larger aerial extent compared to the distant past. It is concluded that rise in temperature modifies both high and low intensity rainfall events, thus altering the uniformity in rainfall distribution. A regionally varied strength of coherence between rainfall uniformity and high and low intensity rainfall is observed which may be due to regionally dependent soil moisture-precipitation feedbacks.