Spatiotemporal analysis of meteorological drought variability in the Indian region using standardized precipitation index

Abstract

Grid (1°latitude × 1°longitude) level daily rainfall data over India from June to September for the years 1951-2007, generated by the India Meteorological Department, were analysed to build monthly time series of Standardized Precipitation Index (SPI). Analysis of SPI was done to study the spatial and temporal patterns of drought occurrence in the country. Geographic spread of SPI-derived Area under Dryness (AUD) in different years revealed the uniqueness of the 2002 drought, with widespread dryness in July. Mann-Kendall trend analysis and moving average based trends performed on the AUD indicated an increasing trend in July. The area under moderate drought frequency has increased in the most recent decade. Ranking of years based on Drought Persistency Score (DPS) indicated that 1987 was the most severe drought year in the country. The results of the study have revealed various aspects of drought climatology in India. A similar analysis with the SPI of finer spatial resolution and relating it to crop production would be useful in quantifying the impact of drought in economic terms.

An evaluation of the Standardized Precipitation Index for assessing inter‐annual rice yield variability in the Ganges–Brahmaputra–Meghna region

“…The Aman/Kharif season extends from June to October/November and depends largely on the rainfall from the monsoon (Subash and Ram Mohan, ; Naresh Kumar et al , ). During these months, June rainfall triggers sowing, July represents the peak sowing period, August is the active growing period, September provides the maximum vegetative phase and harvesting is mostly done during October or November (Naresh Kumar et al , ).…”

“…The Aman/Kharif season extends from June to October/November and depends largely on the rainfall from the monsoon (Subash and Ram Mohan, ; Naresh Kumar et al , ). During these months, June rainfall triggers sowing, July represents the peak sowing period, August is the active growing period, September provides the maximum vegetative phase and harvesting is mostly done during October or November (Naresh Kumar et al , ). Meanwhile the rainfall, which occurs towards the end of the summer monsoon, provides soil moisture and groundwater recharge for the irrigated Boro/Rabi crop sown in the post‐monsoon season after floods have receded (Parthasarathy et al , ; Ruane et al , ).…”

“…A widely used drought index is the Standardized Precipitation Index (SPI), developed by McKee et al (), which can be implemented at different timescales for measuring short‐ and long‐term meteorological droughts and thus applies to various droughts ranging from meteorological to socio‐economic (Narasimhan and Srinivasan, ). In India and Bangladesh, SPI has been found to be a useful index for assessing drought climatology (Patel et al , ; Shahid, ; Pandey et al , ; Pai et al , ; Naresh Kumar et al , ).…”

Drought characterization over India under projected climate scenario

“…Increased risk of drought due to increased prolonged dry spells, total dry days, and decreased light precipitation days over India can be attributed to global warming (Mishra and Liu, 2014). Characterization of droughts in India have been the focus of many studies (Mishra and Singh, 2009;Naresh Kumar et al, 2012;Ojha et al, 2013;Thomas et al, 2015;Mallya et al, 2016;Sharma and Mujumdar, 2017;Zhang et al, 2017). Zhang et al (2017) reconstructed the drought during 1981-2013 in major wheat growing regions in India to demonstrate its implication on wheat production.…”

The implications of geography and climate on drought trend

“…To this end, the degree of drought must first be indexed and classified and an analysis of the correlation of the geographical characteristics of the region and climatic factors with the drought index must be carried out. For the use of SPI as the drought index, most researchers (Shahid, 2008;Logan et al, 2010;Kumar et al, 2012) have focused on SPI trend due to changes in climatic factors, without considering the specific geographical characteristics of the region. However, the influence of geographical factors on SPI trend should be analyzed using detailed geographical information.…”