Thinning out: Although research expeditions to the Hindukush Himalayas have seen an uptick, several critical knowledge gaps still hinder water management in the region | Photo: Shreeshan Venkatesh

Glacier retreat in the Hindukush Himalayas reveals transboundary uncertainties

Rapid warming in the region has increasingly been flagged by scientific assessments. However, outcomes for the region’s water regime, especially the groundwater, is yet to become clear.

“Significant areas of glaciers in the Hindu Kush Himalayan (HKH) region are retreating at an alarming rate,” according to a study recently published by the Observer Research foundation. The report Retreating Glaciers and Water Flows in the Himalayas: Implications for Governance,  authored by Anjal Prakash, research director at the Bharti Institute for Public Policy, Indian School of Business and an IPCC lead author, builds on an extensive review of scientific literature on the water and ice balance in the region.  The report further examines the relationship between glacier decline and the changing surface water and groundwater regimes in the HKH region.

The HKH region, which is an intricate 3,500-km network of mountains, is home to some 54,252 glaciers, with a total area of 60,054 sqkm and projected ice reserves of 6,127 km3. Although only 1.4% of the HKH region is glaciated, the total ice stocks are roughly equal to three times India’s annual volume of rainfall . The region provides freshwater supply to 1.5 billion people living within its folds and in downstream regions in eight countries through thousands of springs and river systems, including some of the world’s largest, fed by glacial melt.

“The HKH region is characterised by a unique hydrogeology, in which springs play a pivotal role. In many parts of HKH, springs are drying up due to prolonged periods of pre-monsoon drought as a result of climate change, threatening the whole way of life for local communities and downstream areas,” says Vishal Singh, executive director of Center for Ecology Development and Research, an action-research NGO based in Dehradun.

Feeding a webwork of rivers

A 2012 study that modelled changes in the hydrological regime in the range estimated that for the upper Indus basin, glacier melt may contribute up to 41% of the total run-off; 13% in the upper Ganga basin; and up to 16% in the upper Brahmaputra. It further added that these rates are higher in the critical dry spring months, when other sources of runoff are scarce. While there is significant disparity between estimates of glacier melt contributions in different river systems, decreasing trends of snow and ice cover in most of the region have been unambiguous.

Major river basins originating in the Hindukush Himalayas

 One such study, published in 2011, which confirmed the declining trend in snow cover, also observed that the critical elevation zones between 5,000m to 7,000m would be the most sensitive to climate change. Slight changes in temperatures at these elevation zones — particularly around the threshold of freezing/melting point — could cause a significant change in the snowmelt.“ It is not only the snow-covered regions, but also the snow depth and the amount of water stored in the snow packs which will impact melting, and this consequently influences the river flow systems and water resources availability that cause substantial changes in the river flows and water resources in spring systems,” the study notes.

With extreme weather added to the mix, the picture gets infinitely more complicated. The recently released review also makes note of changes in seasonal extremes, increased evapotranspiration, and changes in glacier volume.  These changes vary across the Indus, Ganges, and Brahmaputra river basins. In the Indus, the marked effect is on meltwater; for Ganges, the effect is on runoff that is expected to increase; and for the Brahmaputra, climate change may result in enhanced flood risk. In all three basins, though, there is likely to be a decrease in snow and a rise in glacier melt by mid-century according to the review. Initially, there will be an increased amount of meltwater available, but this quantity will decline abruptly as the glacier storage falls.

 The impact of climate change on Himalayan surface and groundwater Interaction

The first signs of impending changes are already visible in HKH’s groundwater resources, notes the recently released review. Groundwater squeezing and seeping through rocks as springs form the main source of water supply to rural and urban hamlets in the entire Himalayan range. Over the years, spring resources in the Himalayas have declined owing to increasing pressures of population, demand and technology. Changes in rainfall patterns and a poor legal policy framework pose further challenges for managing groundwater resources.

These studies, as pointed out by Prakash, show that increased glacier melt might lead to extensive flooding downstream. But gradually, as glaciers continue to retreat and diminish, the amount of meltwater flowing into rivers could decline considerably and abruptly.

Since surface and groundwater systems are interconnected, such a situation may lead to a substantial drop in the rates of groundwater recharge in some regions. Combined with changes in summer monsoon rainfall and surface water flows, it could cause huge water stress in many parts of the HKH region and affect the river basins that relate to the Himalayan glaciers.

A growing concern

The decline of springs has recently become a key source of concern given that a significant population in the mid-hills across the HKH region depends on springs for daily needs. The Koshi river basin shared by Nepal and India exemplifies the risks of groundwater decline in the region. The drying up of 36% of the groundwater springs in a catchment in the basin over the past 20 years has translated into severe water scarcity in more than 60% of the villages dependent on the catchment. Food production, by extension, has declined by 25%, as have the livelihood prospects in traditional forestry and agriculture.

 Increasing evidence  

There has been a recent increase in research seeking to make a connection between the decline of glaciers and climate change, focusing on surface water regimes.

A longitudinal study undertaken for 11 years in two watersheds in the mid-western Indian Himalayan hills in Uttarakhand collected data using automated rain gauges in select sites of the river basins. It measured daily spring flow in all the springs used by residents. The analysis showed that there is a high correlation between precipitation events and spring flows. In a comparable location of the western Himalayan region, another study  observed that the spring flow during rainy and non-rainy seasons is affected by rainfall and recharge area types.

 Uneven impacts

In lower altitudes, the decline in glacial mass balance is not going to affect the systems severely until the middle of the century. After 2050, however, the changes in climatic conditions will likely begin to affect the springs systems, reducing their recharge and flow. In the higher altitudes, these changes will emerge earlier, altering the water flow in rivers and springs.

But even as groundwater levels continue to fall in several locations across the HKH, connections between glacier declines and larger water regimes and human demands are still lacking. According to Prakash, “The interactions between glacial declines and the water regimes — especially the groundwater recharge — remains an understudied subject.  A synchronised planning for the refurbishment of water in the region is absent. The HKH region is trans-boundary in nature, with watersheds spread across various countries therefore a regional approach is necessary for the protection of the HKH’s interconnected systems.”

What is India doing to tackle the issue?

Some Indian states in the region, such as Uttarakhand and Himachal Pradesh, seem to be cognisant of the problem and have taken the first steps towards addressing it. SK Lepcha, former Indian Forest Service officer and a member of consortium working on springshed management in Uttarakhand, told Carbon Copy, “There are 22 representatives hailing from state government, central government and various organisations, who are running a pilot project in reviving some 120 dried springs in Uttarakhand in order to increase ground water recharge. Some 57 springs were revived last year and some 33 this year, but work has come to a standstill due to COVID-19.”

Dr. Savita, head of the Forest Force in Himachal Pradesh, said, “The government is working on some projects to resolve the water shortage due to various factors caused by climate change. This includes enhancing ecosystem services under the JAICA project in collaboration with Japan and taking up micro-irrigation for agriculture and horticulture. Intensive plantation, digging of trenches and the cultivation of mixed forests are some of the other works being undertaken for the same objective.”

But some experts are of the opinion that while minor or fragmented projects are better than no action at all, a more planned effort is required to tackle the issue. Dr. Vishal Singh says, “The Uttarakhand government has no comprehensive development plan dedicated for augmentation of water recharge in order to adapt to the water crisis posed by glacier receding and climate change. There are few organisations who have joined hands with the forest department for pilot projects in the past decade but they have not given desired results. For instance, 90% of the 300 springs in Almora district have already dried up. Still, development projects like Char Dham road widening are not protecting the springs.”

“The HP government has incorporated the subject of augmentation of water recharge in its state action plan for climate change, but the government has failed in its effective implementation and outreach programme,” says Rajan Kotru, former regional programme manager, (Transboundary Landscape) with The International Centre For Integrated Mountain Development, who is now running his own environment organisation in Himachal Pradesh.

“There is no one mega project that the state government has undertaken to tackle the imminent water crisis across the state, involving the line departments and other related organisations, which is quite unfortunate.”

A united effort required

While local communities grapple with the crisis, the issue is still largely falling on deaf years on the national stage. Dr Arun Kansal, head, Regional Water Studies, TERI School of Advanced Study said, “Spring sheds did not receive much attention in the National Water Policy of 2012 and water-related policies in subsequent years as well. Climate change triggered glacier retreats pose a big threat to sustainability of springs, which is beyond the control of local communities to manage.”

Dr. Anamika Barua, professor of economics at  IIT Guwahati, who works on the transboundary water issues in the HHK region, says the region must unite and bring the issue to the fore. “The region must come together and jointly approach the issue with technical and scientific knowledge for better management of the vital water resource both ground and surface water of HKH region, as Prakash’s paper has highlighted.”

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