A study, by Dr Anjal Prakash and commissioned by the Observer Research Foundation (ORF), published in September 2020, has found that the retreat of glaciers in the Hindu-Kush-Himalayan (HKH) region is now affecting the surface water and groundwater availability in the region, thereby adversely affecting springs which are a lifeline for the population in hill areas. Therefore, the study suggests that a logical nationwide policy urgently needs to be developed for springs and Himalayan groundwater, in order to save the region from a severe water crisis in the coming decades.
Studies by the Indian Space Research Organisation (ISRO) state that about 75 per cent of the Himalayan glaciers are retreating at an alarming rate which will increase the variability of water flows to downstream areas and endanger the sustainability of water use in the earth’s most crowded basins. Not only that, receding glaciers would also impact the rates of groundwater recharge in some areas particularly the Ganges basin the most.
The study looks at the interconnectivity between climate change and the ground as well as surface water in the area. There are about 5 million springs in the Himalayas. They are showing a decline because of overuse by an increasing population, retreating glaciers, and depleting groundwater levels. If timely attention is not paid to this issue, it will greatly affect the upper and middle Himalayan inhabitants, who are chiefly dependent on spring water. Climate change is affecting hydrological regimes in the HKH region because of factors like changes in seasonal extremes, increased evapotranspiration, and changes in glacier volume. However, the study forecasts that there would be a decrease in snow and a rise in glacier melt in all three basins by the middle of the century. Therefore, NITI Aayog set up a committee to look at springs in the Himalayas. In many parts of HKH which extends across 3,500 km over eight countries—Afghanistan, Bhutan, Bangladesh, China, India, Myanmar, Nepal, and Pakistan, springs are drying up due to prolonged pre-monsoon drought as a result of climate change, threatening the way of life for local communities and downstream areas. It has the biggest reserves of water in the form of ice and snow outside the Polar Regions. It is also the source of 10 of the largest rivers in Asia. About 1.3 billion people directly depend on the HKH ecosystems, especially for irrigation, power, and drinking water.
For the upper Indus basin, glacier retreat may contribute up to 41 per cent of the total runoff, 13 per cent in the upper Ganga basin, and 16 per cent in upper Brahmaputra. Initially, this will not have a direct impact on water flow in rivers, except in the Indus where 26 per cent flow is from glacier melt, this may change soon.
Courtesy: The Indian Express, Sept 19, 2020