Impact of Climatic Stress on Groundwater Resources in the Coming Decades Over South Asia
Adequate availability of groundwater resource is an indispensable component for the sustainable growth of society and human civilization. Groundwater is the largest source of accessible freshwater resources and as per estimates made, it supplies drinking water to ~36% of world population and ~42% of water used for irrigation (Taylor et al. 2013). According to recent estimates by various surveys (e.g. Shiklomanov 1993), of the 1.4 billion cubic km water available on earth, 2.5% of it is available as freshwater. Of all the freshwater available, 10 million cubic km is estimated to be groundwater which is essential for food security for both developing and developed countries. According to International Panel on Climate Change (IPCC) reports documented since last 20 years (IPCC Report 1996, 1998, 2001, 2008, 2014), the impact of climate change on water cycle including groundwater as an indispensable component is largely uncertain. Very few studies have taken the matter in a holistic way that includes groundwater as an explicit variable. Hence the question: “What is the impact of climate change on groundwater resource?” is yet to be quantified for societal impact studies e.g. chapter 3 of IPCC Report (2014). Any natural resource can be extracted for continuous usage only when the supply is replenished adequately. Hence it is undeniable that extensive usage of groundwater for drinking, agricultural as well as industrial use is sustainable only if the recharge of groundwater is maintained at a constant pace.
RC acknowledges the research support from IITM, an autonomous institute fully supported by the Ministry of Earth Sciences, Govt. of India. Plots are made using NCL-NCAR software and Xmgrace. The work is carried out with facilitation from India-UK Joint water centre (IUKWC). CMIP5 data is directly downloaded from https://pcmdi.llnl.gov/search/cmip5/. GRACE land grid data are available at http://grace.jpl.nasa.gov, supported by the NASA MEaSUREs Program. For information on GRACE NetCDF data used here, website documentation following is referred http://podaac.jpl.nasa.gov/dataset/TELLUS_LAND_NC_RL05. India Meteorological Department, Pune office (IMD) has provided the gridded rainfall data used in this study. The authors would also like to thank Prof. P.K. Sikdar, Department of Environment Management, IISWBM, Kolkata for providing constructive comments and suggestions which improved the manuscript.
- Asoka, A., Gleeson, T., Wada, Y. and Mishra, V. (2017). Relative contribution of monsoon precipitation and pumping to changes in groundwater storage in India. Nat Geosci, 10: 109–117. doi: https://doi.org/10.1038/ngeo2869.
- Balek, J. (1988). Estimation of Natural Groundwater Recharge, I. Simmers (Ed.). Springer.Google Scholar
- CGWB (2007). Manual on Artificial Recharge of Ground Water. Government of India, New Delhi.Google Scholar
- Gleick, P.H. and Adams, D.B. (2000). Water: The Potential Consequences of Climate Variability and Change for the Water Resources of the United States. USGS, Washington D.C.Google Scholar
- IGES-GWP (2012). Technical Report on Issues related to Water and Agriculture in South Asia. IGES-GWP, Hamaya (Japan).Google Scholar
- IPCC Report (1996). Climate Change 1995, Impacts, adaptations and mitigation of climate change: Scientific-technical analyses. Cambridge University Press, UK, London.Google Scholar
- IPCC Report (1998). The Regional Impacts of Climate Change: An Assessment of Vulnerability. Cambridge University Press, UK, London.Google Scholar
- IPCC Report (2001). Climate Change 2001, Impacts, Adaptation and Vulnerability. Cambridge University Press, UK, London.Google Scholar
- IPCC Report (2008). Climate Change and Water. IPCC Technical Paper VI. Cambridge University Press, UK, London.Google Scholar
- IPCC Report (2014). Fifth Assessment Report - Impacts, Adaptation and Vulnerability. Cambridge University Press, UK, London.Google Scholar
- Ministry of Water Resources (2006). Central Ground Water Board. Dynamic Ground Water Resources of India (as on March 2004). Government of India, New Delhi.Google Scholar
- Shiklomanov, I.A. (1993). World Freshwater Resources in Water in Crisis. Oxford University Press, UK.Google Scholar
- UNEP (2008). Freshwater under Threat, South Asia. UNEP-AIT, Nairobi, Kenya.Google Scholar