A double suspension bridge over the Dudh Koshi (a tributary of the
Koshi river) on the way to Namche Bazar, Nepal
(Photo by Robin Lardon/Shutterstock.com).
It is unequivocal that changes in precipitation and temperature patterns are expected due to climate-driven changes, which in turn affect the hydrological regimes of associated river basins.
As reported in IPCC’s Sixth Assessment Report Working Group I, global surface temperature was nearly 1 degree Celcius higher during 2001-2020 when compared to 1850-1900 and global average precipitation on land has increased significantly since 1950.
These findings are a cause for concern for Nepal – a country that is mostly-mountainous which extends from the Earth’s highest peak down to the Terai region. But how does climate change impact this landlocked nation’s water resources?
The development and management of water resources projects should focus on climate-resilient infrastructure and nature-based solutions.
Putting things in the national context, studies show that Nepal’s maximum temperatures have increased from 0.06 to 0.12 degrees Celcius in the mountainous areas and 0.03 degrees Celcius per year in the southern plains in the last quarter of the 20th Century.
Likewise, Nepal’s Ministry of Forest and Environment projects mean temperature rise by 0.9-1.1 degrees Celcius between 2016-2035 and 1.3- 1.8 degrees Celcius by 2036-3065 when compared to 1981-2010.
Nepal is expected to get warmer and dryer as its number of rainy days are expected to decrease, but the precipitation intensity of these rainy days are expected to increase in the future.
It will rain less frequent but more intense and this will result in a likely increase in water-related hazards such as floods.
A living example of these climate trends can be witnessed in the Koshi River Basin – one of the largest tributaries of the Ganga River and the largest river basin in Nepal.
Studies report both rising temperatures and precipitation which will most likely follow an increasing trajectory in the basin.
The 2020 International Journal of Climatology published one of my co-authored studies projecting an increase in both the minimum and maximum temperatures in the basin, which means that both winter and monsoon seasons will be warmer.
Specifically, the northern part of the basin (originating in the Northern Himalayan region) is particularly more sensitive to climate change given its snowy and glacier character, where absolute temperatures are expected to rise by 1.2 degrees in Representative Concentration Pathway (RCP) 4.5 and 1.6 degrees Celsius for RCP8.5 by 2030.
The Upper Koshi River Basin and the major tributaries (Figure by Mishra et al., 2019).
On the other hand, monsoon precipitation is expected to increase for all RCP scenarios; post-monsoon precipitation is also expected to increase in the future, but winter precipitation is projected to decrease.
The pre-monsoon precipitation is also expected to decrease in the coming decades. Based on the ensemble mean of average annual precipitation, Lower Himalaya and High Himalaya regions are sensitive to climate change considering precipitation.
Higher absolute increases in precipitation are expected in the Lower Himalaya region during 2016-2045 (231 mm for climate change scenario RCP4.5 and 270 mm for RCP8.5) and in the High Himalaya region during 2036-2065 (291 mm for RCP4.5 and 419 mm for RCP8.5) and 2071-2100 (391 mm for RCP4.5 and 922 mm for RCP8.5) compared to the base period (1981-2010).
In contrast, Lower Himalaya and High Himalaya regions are sensitive to changes in precipitation in the coming decades.
The spatial and temporal variation in temperature and precipitation will have a direct impact on water resource availability in the rivers and crop irrigation requirements in the region.
In another one of my co-authored studies published in the 2020 International Journal of Water Resources Development, we projected the changes in river water availability in the Koshi River based on the above-mentioned changes in temperature and precipitation for short-term, mid-century, and end-ofcentury periods considering RCPs 4.5 and 8.5.
Within this context, prevailing design considerations for water-related infrastructures such as hydropower dams, bridges, canals, etc., should be reviewed considering climate change impacts on the hydrological regimes of the river systems resulting from changes in precipitation and temperature.
It is also suggested that the development and management of water resources projects should focus on climate-resilient infrastructure and nature-based solutions.
The writer is Joint Secretary (Technical) at Department of Water Resources and Irrigation, Nepal and Project Director of Sikta Irrigation Project.
During the flooding season, boats become the only means of transport in the Kosi River Basin in places within the embankments. (Photo: Manoj Kumar Singh / Gorakhpur News Line)
The Kosi is a transboundary river that springs from the Himalayan slopes of Tibet and flows through the Northern Himalayan region.
The Kosi River Basin covers 74,500km2 and drains into the river Ganga through numerous channels, eventually passing through Bangladesh to the sea in the Bay of Bengal.
The basin supports the lives and livelihoods of 40 million people, more than 80 percent of whom depend on agriculture for food and employment. Now, concern is growing that climate change is disrupting the basin’s ecology and will seriously damage millions of lives.
The basin has already faced repeated disasters including landslides, floods, and glacial lake outbursts that have devastated downstream communities.
In 2020, some 9.6 million people in the Kosi River Basin, reeling from the Covid-19 pandemic, were inundated by monsoon flooding in Nepal, India, and Bangladesh.
There is a growing need for citizen-centered approaches to water governance and transboundary cooperation.
In this article, we call for a more inclusive paradigm of water governance, guided by the needs of riparian communities and an ethos of cooperation and conservation, rather than transboundary water politics and ecologically ineffective infrastructure development.
There is a growing need for citizen-centered approaches to water governance and transboundary cooperation.
The ecology and climate of the Kosi River Basin
The Kosi Basin illustrates the interconnected effects of climate change and man-made interventions on lives and ecosystems in a transboundary basin.
Floods impact agricultural production as fields remain submerged for months. Growing population density, urbanization, and encroachment on watersheds put additional pressure on the basin’s freshwater ecosystems.
Water disasters in the basin, triggered or amplified by poorly planned infrastructure, strike communities without regard to international borders.
In 2008, the Kosi breached the man-made embankments that had been built to control and contain it, with grave consequences for 2.64 million people in India and Nepal, taking lives and destroying livelihoods on both sides of the border.
The floods deposited sand and silt on arable lands that left them unfit for cultivation for years. In Nepal, 4,648 hectares of agricultural land were ruined.
In Bihar, India’s most flood-prone state, the 2008 floods damaged 100,000 hectares of wheat and rice farmland and the livelihoods of around 500,000 farmers.
Communities living along the basin are among the most economically disadvantaged, the most vulnerable to natural disasters, and the least able to adapt and respond to rapid ecosystem degradation.
In India, the Kosi flows through one of the poorest states, Bihar, where a majority of the rural population is dependent on agriculture. In Nepal, 40 percent of the population in the basin lives below the poverty line.
While high-profile hydropower projects in the basin have been a development priority, they are yet to improve livelihoods or other socio-economic benefits in the basin, including electricity access.
These socio-economic inequities were echoed in a series of multi-stakeholder dialogues in the basin, organized by community-based NGOs and organizations supported by The Asia Foundation, in which the communities described the challenges they face in the Kosi River Basin.
Development issues persist across the board, from lack of a minimum wage or access to land to inadequate healthcare, sanitation, and education.
Male migration from the region has increased in the last decade. Women are particularly affected by the lack of sanitation and freshwater for domestic care work.
Riverine communities are adapting to climate change
In the 1950s, thick embankments were constructed along 150km of the Kosi River to defend against flooding. While farmers had traditionally constructed bandhs—low structures of mud and stones to control flooding and support irrigation—these were intentionally temporary, and although flooding still occurred in rural villages, the large expanses of floodplain slowed the flow of floodwaters and reduced damage to property and livelihoods.
The floods nourished agricultural lands in the region. But beginning as early as colonial times, successive governments built permanent embankments that altered the natural drainage of the basin and cut off the river from its surrounding floodplains.
Unlike the traditional bandhs, these embankments often stand some distance from the river, sometimes closer to villages, and completely block the natural drainage of water in the floodplain.
The rationale was to protect farms, livelihoods, and development infrastructure from flood damage, but the effect was often just the opposite.
As the Kosi River flows through the Himalayan mountainous regions, it carries with it large amounts of silt that it deposits onto the plains of Nepal and northern India.
When traditional irrigation channels that conducted water and silt through the floodplains were subsumed by large embankment projects, it altered this flow, causing unchecked accumulation of sand and silt.
Silt deposition near an embankment at Navbhata, Saharasa, Bihar, India, in the Kosi River Basin (Photo: CC BY 3.0 via Wikipedia)
The embankments were equipped with sluice gates that could be opened or closed to control the flow of water in the main river channel, but disrepair and poor management of the gates have allowed silt to accumulate within the embankments, raising the riverbed and causing water to flow into the villages.
There the floodwaters stagnate, depositing silt and sand that make the land inarable. Families in villages between successive embankments must evacuate to higher ground when waters rise.
Often, they are unable to move due to socio-economic reasons and remain excluded from basic government disaster relief.
Multi-stakeholder dialogue on the experience of inundation and flooding in the Kosi River Basin conducted by Gorakhpur Environmental Action Group (Photo: Malavika Thirukode / The Asia Foundation)
Moving from water management to inclusive water governance
Water—its scarcity or abundance—shapes ecosystems and communities. Governments in the Kosi River Basin have pursued a centralized, institutional approach to water governance that has focused on irrigation, flood control embankments, and hydroelectric development.
Experts have observed that inhabitants of the disaster-prone basin live with piecemeal information on environmental risks. Adapting to new extreme weather scenarios requires regional and subregional support systems, projects, and laws.
What is needed is a citizen-centered approach that involves local communities in managing water resources.
When community stakeholders in the basin are involved in resource management, their knowledge of local conditions and familiarity with their own needs create opportunities for more informed, inclusive, and integrated solutions.
The Asia Foundation has partnered with the Gorakhpur Environmental Action Group (GEAG) and the Centre for Policy Research in India, and with ISET-Nepal and Policy Entrepreneurs Inc. in Nepal, to better understand the lives of communities in the basin and their water governance needs.
The project has launched multi-stakeholder dialogues and knowledge-sharing initiatives to develop evidence-based water governance mechanisms and transboundary collaborations in the basin.
A Transboundary Citizen’s Forum has built the capacity of partner organizations to promote community understanding, trust, and collaboration.
Towards transboundary water cooperation
Several mechanisms for cooperation on ecological conservation and resilience already exist. The Sendai Framework for Disaster Risk Reduction 2015–2030 highlights the need for collaborative, regional response mechanisms and revised institutional mandates.
The Thimphu Statement on climate change emphasizes regional cooperation, the sharing of best practices, and an integrated approach to climate change in South Asia.
Other initiatives include intergovernmental platforms for disaster preparedness and information-sharing support for communities to better anticipate and plan for disasters.
Pilot projects are needed to develop local strategies. The time has come to “coexist with the river” rather than opposing its flow.
Malavika Thirukode is a Program Officer and Manvi Tripathi is a former Intern with the Asia Foundation’s India-U.S. Triangular Development Partnership (TriDeP).
Diesel Pumping Set Extracting Water from a Shallow Tube
Well for the Paddy Crop on the Outskirts of Dhaka, Bangladesh
(Photo: Dr. Niladri Gupta, 2022)
Climate change has brought about increased temperature and shifts in precipitation patterns around the world, impacting the water resources sector.
The IPCC’s sixth assessment report (AR6) highlights that changes in extremes have been observed, causing extreme weather events such as heatwaves, heavy precipitation, droughts, and tropical cyclones due to global warming.
Continued global warming is projected to further intensify the global water cycle, spreading its variability, global monsoon precipitation pattern, and the severity of wet and dry events, impacting availability of water resources and their management throughout the world.
Groundwater is an important component of the freshwater regime for agriculture, drinking water supplies, and sustaining ecosystems.
It modulates the temperature and baseflow of rivers, lakes and wetlands; regulates exchanges of nutrients and minerals; and prevents land subsidence and seawater intrusion.
Groundwater, often unseen and neglected, holds immense promise in our adaptation to climate change and needs to be judiciously managed.
According to the United Nations World Water Development Report 2022 (UNWWDR 2022), which uses 2017 data, the global rates for withdrawal of freshwater exceeds 3,881 km3 per year, with groundwater contributing about a quarter of the total withdrawal.
Estimates show that about 959 km3 (959 trillion liters) of groundwater were withdrawn in 2017, out of which 69 percent was for agriculture, 22 percent for domestic and 9 percent for industrial use.
Groundwater is important, for agriculture – food production and security, while domestic use, though smaller in volume, is critical for survival. Almost 50 percent of the global urban population depends on groundwater as the primary source for drinking water and its societal importance far outweighs the volume of extraction.
Figure 1: Groundwater Withdrawal Volumes and Its Share in
Freshwater Withdrawal in the Continents
(Data from UNWWDR, 2022)
Sound groundwater management actions need to be implemented to better safeguard this vital resource
Asia withdraws the highest volume of freshwater: 2,505 km3 every year, of which 657 km3 is groundwater. This represents about 69 percent of the total world groundwater extraction.
These figures are large for Asia, due to its large population and water-intensive agricultural practices in the region. Groundwater withdrawal in South Asia alone is about 401 km3 per year.
Groundwater is a spread resource, available where there is an aquifer and providing direct access to consumers. It is generally of a high quality, and is not directly impacted by rainfall variability.
It is also less polluted than surface water. This poses opportunities for exploitation as well as constraints in the management of this valuable resource.
Water resources management, on a broad scale, requires information on future water availability and requirements of a finer temporal and spatial resolution, to decide on new projects as well as on the operation and maintenance of existing systems.
The existing and future needs and demands are both affected by climate change at the river-basin and local scales. It is certain that the future demands on groundwater and reliance on this resource will increase due to the increasing uncertainty of surface water.
Surface water is directly impacted by climate change and its ushering in of extreme events, more intense rainfall and floods, along with extended periods of drought which create water stresses.
This will potentially increase the rates of groundwater extraction, lowering water tables of already-stressed aquifers.
The direct impacts of climate change on groundwater is still the subject of research. The recharge of aquifers takes place via widespread “evaporation-surplus” rain as well as express recharge pathways such as leakage from rivers, ephemeral streams, wetlands, or lakes. Groundwater systems respond at a slower pace to climate change than surface-water systems.
Rising temperature reduces water available for infiltration by evaporating more water from the surface, soil profile, and even, shallow aquifers, enhancing soil salinity and raising the temperature of shallow groundwater, with possible repercussions on the physio-chemical properties of water.
Conceptual Representation of Key Interactions between
Groundwater and Climate (Taylor et al., 2013)
Variabilities in rainfall affect groundwater differently. It is commonly believed that in humid areas, intense rainfall of a shorter duration limits the time available for infiltration; top soil remains saturated during precipitation and a higher portion of rainfall is partitioned into runoff, thus reducing groundwater recharge.
Variations in aquifer recharge not only change the aquifer yield or discharge, they can also modify the groundwater flow network; e.g. gaining streams may suddenly become losing streams, groundwater divides may change position.
It should be noted that the effect of climate change on groundwater is often impacted by indirect effects, introduced by anthropogenic choices in response to adapting to climate change.
In mountainous areas, snow and glacier melt generally dominate mountain hydrology. Groundwater contribution to runoff can be significant during the spring and the dry season, providing a perennial or seasonal groundwater supply to mountainous springs and ecosystems.
Melting snow, permafrost and glaciers provide a steady water supply for infiltration in the near future, while the distant future could face water scarcity due to the absence of these storages of water.
Climate change impacts are often blamed for a reduction in the flow – or even the drying-up – of springs in Nepal, as well as in Sikkim, in the Eastern Himalayas; but these could be complicated by anthropogenic reasons including land use changes.
The alteration of groundwater quality due to overextraction or polluted runoff including contaminants from fertilizers, pesticides, herbicides or municipal wastes such as pharmaceuticals and personal care products (PPCPs), perfluoroalkyl and polyfluoroalkyl substances (PFAs) and even sewage leakages, are all issues that need to be strictly controlled and managed to assure the sustainability of this vital resource.
It should be understood that climate change’s effects on groundwater are amplified by our actions. The net effect of climate change on groundwater depends not only on changing climatic conditions but also on the physical characteristics of a region, human actions and management decisions.
Sound groundwater management actions need to be implemented to better safeguard this vital resource and enhance our adaptive capabilities, with a better understanding of the impacts of climate change and human interventions on groundwater.
The CARE for South Asia project is carrying out the scoping study on impact of climate change on groundwater resource in Nepal in to better understand the ground realities and the necessity for planning ahead.
The writer is Water Resources Management Specialist in Nepal at ADPC and can be reached at: laxman.sharma@adpc.net
Dr. Hoesung Lee is Chair of the Intergovernmental Panel on Climate Change (IPCC).
ADPC recently held an exclusive ‘Climate Talks’ discussion with this esteemed expert on IPCC’s 6th Assessment Cycle Reports, which range from physical evidence, adaptation and vulnerability, to mitigation of climate change impacts.
The question to lower-income countries would be: ‘How much adaptation is possible?’
You set out on this cycle of reports with the objective of highlighting the consequences of climate change and offering ways to help prevent it. Have you succeeded in reaching those goals so far?
First of all, we need to be realistic about what we have achieved and what we wish to achieve. Our studies and assessments have clearly indicated that we are not on track to limit warming by 1.5 degrees Celsius.
Emissions are now at their highest in human history, and cumulative emissions expected from the existing infrastructure, mostly electricity production, are way over the cumulative emissions permissible to limit warming.
Secondly, to limit warming to 1.5 degrees, global emissions must peak before 2025 and then reduce to about 43 percent of this amount by 2030, relative to 2019 levels.
If we want to limit warming to 2 degrees Celsius, then by 2030, the rate of reduction should be about 27%. But in both cases, net zero has to be achieved by mid-century for 1.5 and the 2070s for 2 degrees.
These modeled scenarios imply that carbon dioxide removal will be unavoidable to achieve net zero. This is to counter the emissions from the hard-to eliminate sectors such as aviation, agriculture and some industrial processes. We are in a phase of both challenge and opportunities.
This third report highlights the pressing issues that need to be considered while combating climate change. What are the main points that you would like to underline, which require action?
Energy must be transformed from its current carbon-intensive structure to low carbon-footprint structures, which means that, by 2050, we must be able to achieve net zero emissions globally.
That implies that a very fast reduction of annual emissions, by close to 7 percent per year, is needed. This is a necessary pathway that we must embrace to achieve climate stabilization.
You have been the Chair of IPCC for the past 7 years; would it be true to say that collaboration between the authors and contributors is now at its optimum and the message has never been stronger?
Optimum is maybe difficult to define, especially when it deals with the collaboration between the different scientific disciplines, but I want to say this:
Though it is always a challenge to sustain an effective interdisciplinary approach, I found that authors working on the IPCC assessments found a great deal of enthusiasm for the intellectual synergies in this atmosphere and framework of assessing vast literatures.
They indicated a strong desire to understand the horizon as well as the big picture, and we do have a variety of successful examples of such interdisciplinary approaches.
Our assessment reports contain examples of cross-chapter boxes or cross-working group boxes; examples include biodiversity over matters related to economics.
I found that collaboration was coming from among the authors, to improve the integrated natures of these climate change problems and solutions.
If we look back at COP26 in Glasgow, it was dubbed the ‘Conference of Adaptation’ and you have been a great advocate of creating coherence between mitigation and adaptation.
How is IPCC trying to enhance the understanding of their costs and benefits, especially in the context of development?
Adaptation, mitigation, and development are very closely interrelated. Development provides the capacity for adaptation and mitigation, and in turn, adaptation contributes to development, which further provides the capacity for mitigation.
Adaptation costs will be higher when global warming is higher. The best enabler of adaptation is mitigation. Many ecosystem-friendly adaptation measures will be possible only when global warming stays below a certain level.
There is a slight difference between adaptation and mitigation benefits – adaptation benefits can mostly be captured locally, whereas mitigation benefits are globally shared with only some local benefits.
Therefore, action means how one can make infrastructure decisions and investments to increase resilience against climate extremes and rising global temperatures, increasing the speed of transformation towards net zero.
This requires long-term planning and finance roadmaps, and this will only be possible with very strong public and private sector partnerships.
For lower-income countries, would you agree that interactions between nature, climate, and humans also require interactions between mitigation and adaptation?
They apply regardless of income classes. Therefore, the question to lower-income countries would be: ‘how much adaptation is possible?’ given the requirements for countries to accomplish so many other things.
Here I want to emphasize that adaptation is a part of, and a very important element of, a development portfolio. Constraints for adaptation are really the availability of finance.
If we have a development strategy on the basis of ‘business as usual’ climate, then that development will never deliver the desired development goal.
Adaptation, especially in lower-income countries, requires financial assistance from various sources as a way of not only having effective adaptation, but also of achieving development goals.
A number of countries have made pledges to reach net zero and lower emissions, especially through their energy sectors. The world is trying to recover from a pandemic at the same time and there is an energy crisis in Europe.
What does that mean for the commitments of those countries?
Well, that’s a very important question. We need to differentiate between the systemic and transient changes.
We have observed rising and fluctuating oil and gas prices for the last two decades and CO2 intensity and content has decreased globally. For the last 10 years, it has decreased 0.3 percent annually and the energy intensity per unit of GDP produced has also declined.
These two important elements – carbon intensity and energy intensity – declined regardless of fluctuating oil and gas prices. Two years ago, oil prices dropped to about US $40 per barrel and people talked about the demand peaking.
I think the recent incident revealed the vulnerability ingrained in current energy systems, in terms of energy security and global supply chains surrounding the energy supply structure. Current incidents will obviously cause, in my understanding, a systemic change toward a reduced supply chain and more localized production.
Now these changes will be in line with net zero transformation pathways, which means more renewable energy use and more technologies to reduce carbon footprints.
The impact of current incidents on systems and behavioral changes will turn out to be a blip in the journey towards net zero, and recent changes will only reinforce the reason for achieving net zero as soon as possible.
Moving forward, how do you see the role of bioenergy in the context of meeting our climate goals?
And, what are some of the challenges in terms of land use and food security, as well as any other challenges or considerations we should be thinking of?
The biggest challenge for bioenergy is sustainability. When scaled up, there is great concern about how such a strategy will collide with the scarcity of land and water.
It will also collide with the desire to preserve biodiversity. Biotechnology itself has an ingrained risk, and sustainability issues arise from its scaling and cost.
When we look at bioenergy, we need to look at the specific choice from the nexus of energy, water, and land.
Considering the economics of climate change and given the vast population of Asia, is the single biggest hurdle in establishing effective sustainable adaptation measures the funding of these measures?
Funding is the critical element of every activity, regardless of adaptation or mitigation, especially for countries in Asia.
A great deal of climate impacts will be expected to appear in this region in a number of sectoral analyses.
Therefore, it is very important that the public and private sources of capital are mobilized for this region, and I believe that multilateral development banks will have a greater role to play to help with its adaptation funding.
If we are looking for signs of progress in dealing with climate issues, would you say that the advances in technology are offering positive opportunities across sectoral mitigation development?
Definitely, yes. There are generally two types of energy policies – the first one would be so-called ‘technology push’ policies such as R&D support and support for training and development, and there are also ‘demand pull’ policies such as technical standards and taxes.
The purpose of those ‘demand pull’ policies are to create incentives and market opportunities. Also, an important element is the transfer of such technologies to the lower-income countries so that those countries will be able to apply them for better adaptation and mitigation activities.
Technology development has a positive spillover both for domestic and international economies, so it’s a good strategy for the development program as well.
Specifically, this Working Group III Report highlights the importance of digital technologies in contributing to the mitigation of climate change; especially when accompanied by dematerialization and smart supply chain management, we should expect a very large dividend of reduced carbon footprints.
Do low-income Asian countries have the economic and technological capacity to fulfill the requirements of the IPCC?
IPCC only provides the available options and actions that countries should consider when they develop climate-related policies.
I’m sure our report will be beneficial to our member Governments’ decision-making towards a better climate domestically as well as globally.
Adaptation, as I said before, is a very important element for domestic development strategies.
Our Report contains a great deal of technical, economic, and environmental elements which can facilitate very appropriate decision-making processes for our member Governments.
I hope our report will be beneficial and useful to decision-makers around the world.
Your next report will be a synthesis of this recent cycle of reports, but presumably you’re already planning the next cycle.
What can we expect to be your areas of focus?
First, the 6th Assessment Cycle clearly indicates that this increasing trend of urbanization generates both a challenge in terms of mitigating climate change as well as adaptation, but also opportunities.
A lot more scientific assessments need to be undertaken about this increasing trend of urbanization in terms of climate change actions and developing strategies.
Second will be a better understanding of the regional information and the decisions being made by local and sub-national governments, which all require very detailed information about climate extremes and other matters related to climate changes and their abilities.
Therefore, the general direction will require a further understanding of climate issues.
Dr. Hoesung Lee spoke to Vidya Rana, Senior Communications Manager, ADPC.
