Trends and extreme value analysis of rainfall pattern over homogeneous monsoon regions of India
Trends and extreme value analysis of rainfall pattern over homogeneous monsoon regions of India
复制标题
印度同质季风区降水格局趋势及极值分析
DOI：
10.1007/s11069-014-1127-2
复制
发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
R. Uma
中科院分区：
文献类型：
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作者：
T. V. Lakshmi Kumar;K. Koteswara Rao;H. Barbosa;R. Uma
研究了1871-2008年印度不同均匀季风区季风前、季风和季风后降水的年代际变化趋势。试图了解季风降水与全球厄尔尼诺和拉尼娜遥相关的关系，并与达尔文气压和尼诺3.4海表温度(Niño 3.4 SST)进行了相关分析。相关分析表明，季风降雨量与ENSO指数在年代际尺度上的相关性明显高于与年尺度上的相关性。研究还发现，与强厄尔尼诺年相比，西北地区受中等厄尔尼诺年的影响更大。东北中部和东北部地区不能对弱、中度和强拉尼娜事件产生任何影响。作者还对印度不同的均匀季风区以及整个印度进行了极值分析。结果表明，未来10年、20年、50年和100年的降水返回值随着重现期的延长而增大。东北(湿润气候型)和西北部(干旱气候型)极端降雨记录的阈值年数的不均一性描述了气候变异性。研究结果有助于决策者了解不同重现期的超雨量，为制定风险管理策略提供参考。
Trends of pre-monsoon, monsoon and post-monsoon rainfall pattern were studied on decadal basis over different homogeneous monsoon regions in India for the period 1871–2008. It is attempted to understand the relation of monsoon rainfall with the global teleconnections of El Niño and La Niña, for which the correlation analysis has been carried out with Darwin pressure and Niño 3.4 sea surface temperature (Niño 3.4 SST). The correlation analysis inferred that the significant correlations were observed when monsoon rainfall is related to ENSO indices on decadal scale than on annual ones. The study also found that the north-west region is more affected by the moderate El Niño years compared to strong El Niño years. The regions Central North-East and North-East could not make any difference among weak, moderate and strong La Niña events. The authors also have carried out the extreme value analysis over different homogeneous monsoon regions of India as well as for whole India. The results show that the return values of rainfall are increasing with the return periods for the forthcoming 10, 20, 50 and 100 years. The heterogeneity in number of threshold years that were recorded for the extreme rainfall over north-east (humid climatic type) and north-west (arid climatic type) described the climate variability. The results of the present study may be useful for the policy makers in understanding the rainfall exceedance in different return periods for planning the risk management strategies.