Spatial and temporal appraisal of drought jeopardy over the Gangetic West Bengal, eastern India

Krishna Gopal Ghosh

doi:10.1186/s40677-018-0117-1

Abstract

BackgroundIn the contemporary era of global warming there is growing need to detail geographical variations of drought risk so as to investigate the impact of climate change in the densely populated agricultural tract of Gangetic West Bengal (GWB), eastern India. In aim to assess drought jeopardy at the regional scale, the present study deals with temporal trend and spatial pattern of drought during the last century over GWB. Standardized Precipitation Index (SPI) has been used to detail geographical variations of drought intensity, duration, frequency etc. at multiple time steps. Non-parametric Mann-Kendall test and Sen’s slope estimator are used to detect the trends and trends slope. In addition, the article focuses on developing a Composite Drought Risk Index (CDRI) integrating 10 parameters pertaining to drought exposure to detect which regions are most exposed to drought.ResultsThe results portray a very diverse but consistent picture. The last century exhibits some consecutive deficit and surplus phases and after 1950s the extremity of surplus and deficit as well as drought duration have increased substantially. The impact of drought is expected to be rigorous at or adjacent areas of the western degraded plateau, particularly the northern Rarh and moribund delta where the drought intensities tend to increase while the rainfall as well as recurrence interval of drought tend to decrease.ConclusionsIn a nutshell, this work provides evidences demonstrating the extension and intensification of aridity in the northern Rarh plain and Moribund delta. Such altered hydrolo-meteorological system hence calls for review of the agricultural practices and water use in GWB. The CDRI provides a means of obtaining a broad overview of drought risk and supposed to allow decision makers more in-depth investigation.

Highlights

Water scarcity is one of the major threats to contemporary water resources management (Bates et al 2008)
Water paucity is being further compounded by discrepancy in precipitation and rise of temperature because of climate change (IPCC 2013)
In India, the total water demand will increase up to 32% by 2050 (Amarasinghe et al 2007) and 1/2 of the cultivated area will continue to be under rain-fed farming even after the full irrigation potential of the country is utilized (CRIDA 2007)

Summary

Introduction

Water scarcity is one of the major threats to contemporary water resources management (Bates et al 2008). The article focuses on developing a Composite Drought Risk Index (CDRI) integrating 10 parameters pertaining to drought exposure to detect which regions are most exposed to drought This densely populated tract (about 1051 person km− 2) which impart with a vast expanses of fertile alluvial soil is the hub of rice and jute cultivation as well as (freshwater) fish production. According to 2011 census the state’s population of 72% resides in rural areas and 88% of the total land holdings belong to marginal and small farmers (AD-GoWB 2009) Agriculture in this region is mainly rain-fed and rainfall extremities put heavy stress on not merely agricultural activities but other economic activities . All these demonstrate the sensitiveness to rainfall availability on socio-economic fabric of this region

Methods

Results

Conclusion