NASA’s Report on Hydrological Change

Why in news?

NASA satellite observations of Earth has found that there is a serious decline in the availability of freshwater in India.

What are the findings of the study?

• NASA used data on human activities to map locations where freshwater is changing around the globe.
• This is the first time that observations from multiple satellites in a thorough assessment of how freshwater availability is changing everywhere on Earth.
• In some regions water supplies were found to be relatively stable, others experienced increases or decreases.
• The study found that Earth’s wet land areas are getting wetter and dry areas are getting drier due to a variety of factors.

What is the reason behind this decline of fresh water?

• The factors for this phenomenon includes human water management, climate change and natural cycles.
• Distinctive pattern of the wet land areas of the world getting wetter those are the high latitudes and the tropics and the dry areas in between getting dryer.
• Pumping groundwater for agricultural uses is a significant contributor to freshwater depletion throughout the world.
• Groundwater levels are also sensitive to cycles of persistent drought or rainy conditions

What are the implications for India?

• Areas in northern and eastern Indiaare among the hotspots where overuse of water resources has caused a serious decline in the availability of freshwater that is already causing problems.
• In northern India, groundwater extraction for irrigation of crops such as wheat and rice have caused a rapid decline in available water, despite rainfall being normal throughout the period studied.
• The extractions in these parts has already exceed recharge during normal precipitation and does not bode well for the availability of groundwater during future droughts.

Source: The Hindu, Business Line