Supplies and Tipping Points for Water
Water data map, average storage is higher (blue) or Lower (red) 2002-2016 (credit: NASA)
In a 'first-of-its-kind' study, NASA combined diverse Earth satellite observations with water measurement data to map 'hotspots' where freshwater is changing around the globe. Publishing in Nature, researchers at the Goddard Space Flight Center found the Earth’s wetlands are getting wetter while drylands are getting drier. The changes were mapped using 14 years of measurements. The changes are due to multiple factors including human water-use management, climate change, and natural cycles. NASA applied global observations gathered by the Gravity Recovery and Climate Experiment (GRACE) to track and map freshwater trends over 34 regions. Collaborator Jay Famiglietti at the Pasadena's Jet Propulsion Laboratory said:
What we are witnessing is major hydrologic change. We see a distinctive pattern of the wetland areas of the world getting wetter – those in the high latitudes and the tropics – and the dryland areas in between getting dryer. Embedded within the dry areas we see multiple "hotspots" resulting from groundwater depletion.
The Nature article concludes that water availability is one of the greatest environmental and international challenges facings countries everywhere. Potentially 50% of the world's population is now facing water supply problems and limits.
Published almost simultaneous to the NASA report, a case study of water stress appeared from India. This populous country is currently experiencing a severe water crisis and the situation may be its worst in its history. An Indian analysis, Composite Water Management 2018, stated:
data was gathered from 24 of India's 29 states (83%) and shows the current (water) situation is only going to get worse with 21 cities likely to run out of groundwater by 2020. It’s a matter of great concern that 600 million people in India face high to extreme water stress. About three-fourths of Indian households do not have drinking water at their premise. With nearly 70% of the India's water being contaminated, the country is now placed at 120th amongst 122 countries in water quality ranking.
Pursuing a personal investigation of a river in India a pair of American mountaineers, Pete McBride and Jake Norton, traced the Ganges River from the high Himalayas to the Bay of Bengal. McBride and Norton "followed the water" from source-to-sea. Their trek is followed in a documentary film, Holy, un-Holy River. The film tells the powerful story of a sacred river revered by a billion people, dependent on its water and considered the source of life and death. The film serves as a cautionary tale of inspiration, water pollution, and an environmental tragedy.
India isn't alone in facing a water crisis. Australia, South Africa, and the Colorado River in the USA all face serious over demand, drawdowns, and conservation issues.
Demands on water supplies, particularly groundwater, are well known and documented. However, solutions remain scattered and contentious. Depending on specific locations, improvement in water conservation could include changing use patterns including pricing, replacing agricultural systems with more drought tolerant crops, recycling waste water, desalinization, and basic conservation.
Many of these changes could represent challenges from vested interests to implement. The issue of climate change and water supplies is now a crisis with tipping points being crossed.