Current Science

Open Access Open Access  Restricted Access Subscription Access

The Chennai Water Crisis: Insufficient Rainwater or Suboptimal Harnessing of Runoff?


Affiliations
1 Fulbright-Nehru Fellow at the Indian Institute of Technology, Mandi 175 001,, India
2 Department of Atmospheric and Oceanic Science, University of Maryland College Park, United States
3 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, United States
 

Chennai experienced acute water shortage during 2019 summer, and four years prior, an earlywinter deluge. Analysis of 116 years (1901–2016) of rainfall in Chennai Sub-basin shows a weak climate change signal: Winter monsoon rainfall, has slightly increased, especially in December. The much larger Cauvery basin to the south also exhibits a nondescript climate change signal in winter rainfall. Late summer (September) rainfall in the Cauvery Basin has, however, precipitously declined in recent years (1987–2016). We show that this decline, as well as the mid-20th century increase, are attributable to natural multidecadal climate variability (Atlantic Multidecadal Oscillation) – cautioning against cavalier attributions of recent-period trends and the Chennai Water Crisis to climate change. Analysis of runoff – the rainwater leftover after its hydrologic and atmospheric processing – shows that harnessing even half of the winter monsoon runoff in the Chennai Sub-basin can satiate the city’s water demand for about seven months; and without needing new reservoir facilities. The present analysis suggests that Chennai’s water woes arise not from insufficient rainwater, but from the suboptimal harnessing of related runoff.

Keywords

Climate Change, Monsoon Rainfall, Multidecadal Variability, River Basin, Runoff.
User
Notifications
Font Size

  • Mishra, A. K., Monitoring Tamil Nadu flood of 2015 using satellite remote sensing. Nat. Hazards, 2016, 82, 1431–1434; doi:10.1007/s11069-016-2249-5

  • The Economist, Next time by water. 12 December 2015; https://www.economist.com/asia/2015/12/12/next-time-by-water

  • Narasimhan, B., Bhallamudi, S. M., Mondal, A., Ghosh, S. and Mujumdar, P., Chennai floods 2015: a rapid assessment. Interdisciplinary Centre for Water Research, Indian Institute of Science, Bengaluru, 2016.

  • Patel, K., Water Shortages in India, NASA’s Earth Observatory, 19 June 2019; https://earthobservatory.nasa.gov/images/145242/water-shortages-in-india

  • Sreekala, P. P., Vijaya Bhaskara Rao, S., Rajeevan, K. and Arunachalam, P. P., Combined effect of MJO, ENSO and IOD on the intraseasonal variability of northeast monsoon rainfall over south peninsular India. Climate Dyn., 2018; https://doi.org/10.1007/s00382-018-4117-3.

  • Krishnamurthy, L. et al., Causes and probability of occurrence of extreme precipitation events like Chennai 2015. J. Climate, 2018, 31(10), 3831–3848; see figure 1.

  • Sengupta, A. and Nigam, S., The northeast winter monsoon over the Indian subcontinent and Southeast Asia: evolution, interannual variability, and model simulations. J. Climate, 2019, 32, 231–249; see figures 2 and 3.

  • Sengupta, A., Sea surface temperature-based statistical prediction of South Asian summer monsoon rainfall distribution, Ph.D. thesis, University of Maryland Graduate School, College Park, USA, 2019, p. 164; see figure 3.2.

  • Kumar-Rao, A., India’s water crisis could be helped by better building, planning. National Geographic, 15 July 2019; https://www.nationalgeographic.com/environment/2019/07/indiawatercrisis-drought-could-be-helped-better-building-planning/

  • Chennai Metropolitan Water Supply and Sewage Board; http://123.63.203.150/public/lake.htm

  • Sikka, D. R., Some aspects of the large scale fluctuations of summer monsoon rainfall over India in relation to fluctuations in the planetary and regional scale circulation parameters. Proc. Indian Acad. Sci. Earth Planet Sci., 1980, 89, 179–195.

  • Rasmusson, E. M. and Carpenter, T. H., The relationship between eastern equatorial Pacific sea surface temperatures and rainfall over India and Sri Lanka. Mon. Weather Rev., 1983, 111, 517–528.

  • Nikku, B. R., Water rights, conflicts and collective action: case of Telugu Ganga Project, India. Presentation at the Tenth Biennial Conference of the International Association for the Study of Common Property, Mexico, 2005; http://dlc.dlib.indiana.edu/dlc/bitstream/handle/10535/1094/Nikku_Water_040513_Paper-088.pdf

  • The New Indian Express, 10 January 2019; https://www.newindianexpress.com/states/andhra-pradesh/2019/jan/10/chennai-may-not-get-full-quota-of-krishna-water-from-ap-in-2019-1923178.html

  • The Times of India, Chennai City Edition, 20 April 2019; https://timesofindia.indiatimes.com/city/chennai/veeranam-laketurnsa-major-water-supplier-for-the-city/articleshow/68960792.cms

  • Minjur (https://chennaimetrowater.tn.gov.in/desalination.html) and Nemmeli (https://chennaimetrowater.tn.gov.in/desalination-Nemmeli.html)

  • Gopalakrishnan, S., Water warriors of Chennai. India Water Portal, 19 March 2014; https://www.indiawaterportal.org/articles/waterwarriorschennai-ragade-and-raghavan

  • Jayaraman, N., Viewpoint: Why India’s Chennai has run out of water. BBC, 2 July 2019; https://www.bbc.com/news/world-asiaindia48797399

  • Frayer, L., The water crisis in Chennai, India: who’s to blame and how do you fix it? National Public Radio, 18 July 2019; https://www.npr.org/sections/goatsandsoda/2019/07/18/742688141/the-water-crisis-in-chennai-whos-to-blame-how-do-you-fix-it

  • Amante, C. and Eakins, B. W., ETOPO1 1 arc-minute Global Relief Model: procedures, data sources, and analysis. NOAA Technical. Memo NESDIS NGDC-24, 2009, p. 25.

  • BfG, Major river basins of the world, Global runoff data Centre, Federal Institute of Hydrology, Germany, 2007.

  • FAO, AQUAMAPS Global Spatial Database on Water and Agriculture: rivers/water bodies. Food and Agriculture Organization, Rome, Italy.

  • Lehner, B., Hydro HydroSHEDS, Technical documentation, version 1.2. Conservation Science Program, World Wild Life Fund, USA, 2013, p. 25.

  • Wang, Y. Q., MeteoInfo: GIS software for meteorological data visualization and analysis. Meteorol. Appl., 2016, 21, 360–368; https://doi.org/10.1002/met.1345.

  • Grid Analysis and Display System (GrADS), COLA, George Mason University, Fairfax, VA; http://cola.gmu.edu/grads/

  • Schneider, U., Becker, A., Finger, P., Meyer-Christoffer, A. and Ziese, M., GPCC Full Data Monthly Product Version 2018 at 0.25°: Monthly land-surface precipitation from rain gauges built on GTS-based and historical data; doi:10.5676/DWD_GPCC/FD_M_V2018_025.

  • Pai, D. S., Sridhar, L., Rajeevan, M., Sreejith, O. P., Satbhai, N. S. and Mukhopadhyay, B., Development of a new high spatial resolution (0.25° × 0.25°) Long period (1901–2010) daily gridded rainfall data set over India and its comparison with existing data sets over the region. Mausam, 2014, 65(1), 1–18.

  • Ghiggi, G., Humphrey, V., Seneviratne, S. I. and Gudmundsson, L., GRUN: An observations-based global gridded runoff dataset from 1902 to 2014. Earth Syst. Sci. Data Discuss, 2019, doi:https://doi.org/10.5194/essd-2019-32

  • Zhang, R. and Delworth, T. L., Impact of Atlantic multidecadal oscillations on India/Sahel rainfall and Atlantic hurricanes. Geophys. Res. Lett., 2006, 33, L17712.

  • Krishnamurthy, L. and Krishnamurthy, V., Decadal scale oscillations and trend in the Indian monsoon rainfall. Climate Dyn., 2014, 43, 319–331.

  • Nigam, S., Zhao, Y., Ruiz-Barradas, A. and Zhou, T., The southflood north-drought pattern over Eastern China and the drying of the Gangetic Plain: observations, simulations, and origin. In Climate Change: Multidecadal and Beyond (eds Ghil, M. et al.), World Press, 2016, p. 376.

  • Enfield, D. B., Mestas-Nuñez, A. M. and Trimble, P. J., The Atlantic multidecadal oscillation and its relation to rainfall and river flows in the continental US. Geophys. Res. Lett., 2001, 28, 2077–2080; https://doi.org/10.1029/2000GL012745.

  • Cleveland, W. S. and Loader, C. L., Smoothing by local regression: principles and methods. In Statistical Theory and Computational Aspects of Smoothing (eds Haerdle, W. and Schimek, M.G.), Springer, 1996, pp. 10–49; doi https://doi.org/10.1007/978-3-642-48425-4_2

  • Nigam, S., Guan, B. and Ruiz-Barradas, A., Key role of the Atlantic multidecadal oscillation in 20th-century drought and wet periods over the Great Plains. Geophys. Res. Lett., 2011, 38, L16713, https://doi.org/10.1029/2011GL048650.

  • Kavvada, A., Ruiz-Barradas, A. and Nigam, S., AMO’s structure and climate footprint in observations and IPCC AR5 climate simulations.Climate Dyn., 2013, doi:10.1007/s00382-013-1712-1.

  • Nigam, S., Sengupta, A. and Ruiz-Barradas, A., Atlantic–Pacific links in observed multidecadal SST variability: is Atlantic multidecadal oscillation’s phase-reversal orchestrated by Pacific decadal oscillation? J. Climate, 2020, 33, 5479–5505.

  • Nigam, S. and Ruiz-Barradas, A., Seasonal hydroclimate variability over North America in Global and Regional Reanalyses and AMIP simulations: varied representation. J. Climate, 2006, 19, 815–837.

  • Trenberth, K. E. and Jones, P. D., Climate Change 2007: The Physical Science Basis (eds Solomon, S. et al.), Cambridge University Press, 2007, pp. 235–336.

  • Raghavan, S., Rainwater Harvesting – The Success Story of Chennai, 2018; http://site.ieee.org/indiacouncil/files/2018/08/p30p34.pdf


Abstract Views: 396

PDF Views: 153




  • The Chennai Water Crisis: Insufficient Rainwater or Suboptimal Harnessing of Runoff?

Abstract Views: 396  |  PDF Views: 153

Authors

Sumant Nigam
Fulbright-Nehru Fellow at the Indian Institute of Technology, Mandi 175 001,, India
Alfredo Ruiz-Barradas
Department of Atmospheric and Oceanic Science, University of Maryland College Park, United States
Agniv Sengupta
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, United States

Abstract


Chennai experienced acute water shortage during 2019 summer, and four years prior, an earlywinter deluge. Analysis of 116 years (1901–2016) of rainfall in Chennai Sub-basin shows a weak climate change signal: Winter monsoon rainfall, has slightly increased, especially in December. The much larger Cauvery basin to the south also exhibits a nondescript climate change signal in winter rainfall. Late summer (September) rainfall in the Cauvery Basin has, however, precipitously declined in recent years (1987–2016). We show that this decline, as well as the mid-20th century increase, are attributable to natural multidecadal climate variability (Atlantic Multidecadal Oscillation) – cautioning against cavalier attributions of recent-period trends and the Chennai Water Crisis to climate change. Analysis of runoff – the rainwater leftover after its hydrologic and atmospheric processing – shows that harnessing even half of the winter monsoon runoff in the Chennai Sub-basin can satiate the city’s water demand for about seven months; and without needing new reservoir facilities. The present analysis suggests that Chennai’s water woes arise not from insufficient rainwater, but from the suboptimal harnessing of related runoff.

Keywords


Climate Change, Monsoon Rainfall, Multidecadal Variability, River Basin, Runoff.

References





DOI: https://doi.org/10.18520/cs%2Fv120%2Fi1%2F43-55