Abstract

The present study examines the spatial and temporal changes in extreme rainfall events (EREs) across the Godavari river basin to develop adaptation strategies for vulnerable regions by understanding opportunities and risks. Indices such as consecutive dry and wet days, daily intensity, one-day highest precipitation, days with rainfall > 10 mm and 20 mm have been computed over the Godavari basin for the time period 1901–2015, and changes are compared between the two time periods 1901–1976 and 1977–2015. This study examines long-term trends on monthly and seasonal scales and climatological characteristics of EREs to understand the observed spatiotemporal changes in EREs. Analysis of EREs in the monsoon months further indicates significant trends over both traditionally “high-rainfall regions” (Humid) and “low-rainfall regions” (semiarid). In low-rainfall region, an increase in mean and coefficient of variability of annual rainfall has been identified during 1977–2015 as compared to pre-1977 period. It is also found that the month of September experienced statistically significant increase in frequency and intensity of all wet extreme rain indices during the period 1977–2015. Extremes in high- and low-rainfall regions show significant increase during 1977–2015 as compared to 1901–1976. Century scale analysis of extreme events with reference to regional level changes would help in looking at the grass root reality for the estimation of water budget as well as for developing region-specific adaptation measures and crop contingency plans. These findings would feed into state action plan for climate change to take appropriate measures to combat changing and rapidly occurring EREs in different climate zones of Godavari basin.

Graphic abstract

中文翻译：

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观察到印度戈达瓦里盆地半干旱和潮湿地区极端降雨指数的变化：风险和机遇

摘要

本研究考察了戈达瓦里河流域的极端降雨事件（ERE）的时空变化，以通过了解机会和风险来制定针对脆弱地区的适应策略。计算了戈达瓦里盆地1901-2015年期间的连续干旱和潮湿天数，日强度，一天的最高降雨量，降雨量大于10毫米和20毫米的天数等指标，并比较了这两个时间之间的变化1901-1976年和1977-2015年。这项研究检查了ERE的月度和季节尺度的长期趋势以及气候特征，以了解ERE的时空变化。对季风月中的ERE的分析进一步表明，传统上的“高雨量地区”（Humid）和“低雨量地区”（塞米利德）都有明显的趋势。在低雨量地区，与1977年前相比，在1977-2015年期间发现了年降水量的均值和变异系数。还发现，在1977-2015年期间，9月份所有湿极端降雨指数的频率和强度都有统计学上的显着增加。与1901-1976年相比，1977-2015年期间，高雨量区和低雨量区的极端水量显着增加。参照区域水平变化对极端事件进行世纪尺度的分析，将有助于从基层看待现实，以估算水预算，并制定针对特定区域的适应措施和作物应急计划。

图形摘要