A high-resolution assessment of climate change impact on water footprints of cereal production in India

Santosh S. Mali,Paresh B. Shirsath,Adlul Islam

doi:10.1038/s41598-021-88223-6

Abstract

Water footprint (WF), a comprehensive indicator of water resources appropriation, has evolved as an efficient tool to improve the management and sustainability of water resources. This study quantifies the blue and green WF of major cereals crops in India using high resolution soil and climatic datasets. A comprehensive modelling framework, consisting of Evapotranspiration based Irrigation Requirement (ETIR) tool, was developed for WF assessment. For assessing climate change impact on WF, multi-model ensemble climate change scenarios were generated using the hybrid-delta ensemble method for RCP4.5 and RCP6.0 and future period of 2030s and 2050s. The total WF of the cereal crops are projected to change in the range of − 3.2 to 6.3% under different RCPs in future periods. Although, the national level green and blue WF is projected to change marginally, distinct trends were observed for Kharif (rainy season—June to September) and rabi (winter season—October to February) crops. The blue WF of paddy is likely to decrease by 9.6%, while for wheat it may increase by 4.4% under RCP4.5 during 2050s. The green WF of rabi crops viz. wheat and maize is likely to increase in the range of 20.0 to 24.1% and 9.9 to 16.2%, respectively. This study provides insights into the influences of climate change on future water footprints of crop production and puts forth regional strategies for future water resource management. In view of future variability in the WFs, a water footprint-based optimization for relocation of crop cultivation areas with the aim of minimising the blue water use would be possible management alternative.

Highlights

Water footprint (WF), a comprehensive indicator of water resources appropriation, has evolved as an efficient tool to improve the management and sustainability of water resources
Spatial variation in the total, blue and green water use of cereal crops are presented as Fig. S1 and the temporal trends in ETc of paddy and wheat as representative kharif and rabi season crops is presented in Fig. S2 in Supplementary Material
This study presents a comprehensive methodological framework to assess the WFs of cereal production in India considering high resolution (0.5° latitude × 0.5° longitude) assessments of crop water requirements

Summary

Introduction

Water footprint (WF), a comprehensive indicator of water resources appropriation, has evolved as an efficient tool to improve the management and sustainability of water resources. Recent estimates using bias corrected projections indicate a warmer (3–5 °C) and wetter (13–30%) climate in South Asia in the twenty-first century[8] Climate change has both direct and indirect impacts on ecosystems, social economics, agriculture and is likely to intensify the pressure on global water resources[9]. Crop management practices like early planting and use of cultivars most suitable for warmer climates have been practiced in some regions of the world[16, 17]

Results

Discussion

Conclusion