Does water–energy–food nexus modeling have a role to play in water management?

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When it comes to water management and conservation, it is critical to balance the needs of domestic users, small-scale and industrial irrigators, hydro-electricity producers, and manufacturers to ensure that improvements in access to water for one group of water users does not impede the progress of others. We must also consider the impacts on biodiversity and ecosystems, and the challenges posed by climate change and increasingly erratic rainfall.

Pakistan is acutely aware of these interlinkages, having experienced them during the devastating floods of 2022. At this year’s Pakistan Water Week, the CGIAR Initiative on NEXUS Gains hosted a session on the potential of water–energy–food (WEF) modeling to understand the interplay between these systems and improve overall water management within the context of a changing climate. Titled “Water–energy–food (WEF) nexus modeling: A fad or the future?”, the event’s speakers underscored the merits of using integrated modeling frameworks through a series of case studies.

Moving from theory to practice

Over the past two years, NEXUS Gains researchers reviewed more than 700 studies published on the WEF nexus and categorized them according to key parameters, including methods used in the studies. The session’s first speaker, Dr Bunyod Holmatov from the International Water Management Institute (IWMI), discussed the implications of the findings. While the use of modeling is quite common, he said, the key takeaway was that it currently has few practical outcomes. “Less than 3 percent of reviewed documents report on-the-ground change, meaning the nexus is still very much theoretical. We’re talking about fewer than 20 outcomes from more than 700 publications.”

Dr Holmatov and his colleagues at NEXUS Gains are applying the lessons learned to their own modeling work in Central Asia. Using the University of Manchester’s Pywr modeling tool, they are exploring the nexus in the Aral Sea Basin, which has been decimated following decades of mismanagement during the Soviet era. When attempting to apply the model across the entire basin, data gaps, stakeholder buy-in, and coordination emerged as factors stalling quick progress. The team therefore decided first to model a small tributary of the basin. Working at a smaller scale requires less data and coordination, and results can be produced more quickly and can be used to gain support from stakeholders by demonstrating the model’s capabilities. Moreover, learnings from the small-scale application can subsequently be applied to the entire basin, saving time and other resources.

Lessons from the Aral Sea Basin are highly applicable to the Indus, too: in both regions, agriculture is the largest consumer of water; water is generated and more widely available upstream, but the need is greater downstream; and water stress is at similar levels. There is also a conflict between water needs for irrigation and for electricity generation in both basins.

“River basins and water resources present very complex systems,” summarized Dr Holmatov. “But so do energy and food systems. So regardless of our point of entry, we need to understand how any intervention would affect the dynamics. The models simplify very complex information and help us understand benefits and trade-offs of interventions in these complex systems.”

Increasing taxes to better distribute water use across sectors

A very different model was presented by the second speaker, Dr Steve Davies from the International Food Policy Research Institute. Given Pakistan’s growing population, as well as the pressures of climate change, he explained, agriculture must significantly reduce its water use over the next 20 years to make it available for other sectors. Dr Davies’ whole-economy model incorporates producers, consumers, governments, and trade. The modeling system was used to explore the potential of water savings through imposing commodity taxes on rice and sugarcane acreage. Using alternative scenarios, he presented the water conservation potential and trade-offs with other sectors.

The model showed that, while the reduction of rice area released water for use in other sectors, a reduction in sugarcane area instead increased agricultural water use, because sugarcane covers two crop seasons. Dr Davies also pointed to the significant impacts of climate change. Once climate change was considered in the model, increasingly severe water scarcity made it extremely difficult to extract water from irrigation through commodity taxes. More focus on changing cropping patterns and irrigation practices, as well as the development of drought-resistant varieties, will therefore be needed. Buying tubewells from farmers or promoting methods for non-agricultural purchases of water need to be considered as well.

On reflection – fad or future?

Five expert panelists were invited to share their reflections on the presentations and whether they thought WEF nexus modeling was a fad or the future.

Dr Bushra Yasmin of Fatima Jinna Women University was undecided on the future of modeling, but pointed to the importance of engaging small farmers, “because they are the main stakeholders. They should be made part of the consultation process to ensure realistic outcomes and delivery.”

Dr Imran Saqib Khalid, Director of Governance and Policy at the World Wide Fund for Nature, was also uncertain about modeling’s potential, as there remains significant room for improvement. “Are we really going down to the communities, to the local government level, to the ground, essentially, and trying to address the needs of the ecosystem in a broader manner, rather than just looking at it in a vacuum?” he asked.

Further suggestions on how to adapt the model in Pakistan were proposed by Dr Iqrar Ahmad Khan, Vice Chancellor of the University of Agriculture, Faisalabad. His ideas included modeling reductions in wheat acreage and exploring changes in productivity by planting shorter-duration crops.

An enthusiastic thumbs up to modeling was the response from Dr Muhammad Jehanzeb Cheema, from IWMI Pakistan. He recalled that in the early days of his career there was no concept of the WEF nexus, which made it challenging to bridge the gap between science and policy. By considering the WEF nexus, it is now easier to progress with analyses on water management and conservation.

Finally, Dr Bashir Ahmad, Director of the Climate, Energy and Water Research Institute at the Pakistan Agricultural Research Council, noted the potential of WEF modeling to analyze the impacts of climate change on water availability – not just in terms of absolute quantities, but also with regards to the location and duration of extreme weather events, such as 2022’s floods.

Considering these responses, session moderator and NEXUS Gains Co-Lead, Dr Claudia Ringler, summarized that WEF modeling “is overall more future than fad, and clearly the models are already very good in terms of generating discussions. But there is much more to be done on environmental systems and engagement with policymakers to actually achieve policy change.”

Did you miss the webinar? You can watch it here.

View the presentation by Bunyod Holmatov

View the presentation by Steve Davies

You can catch up on all the previous NEXUS Gains Talks here, with links to watch recordings and download presentations.

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This work was carried out under the CGIAR Initiative on NEXUS Gains, which is grateful for the support of CGIAR Trust Fund contributors:

Header image: Five panellists share their perspectives at the Pakistan Water Week seminar moderated by Claudia Ringler, NEXUS Gains Co-Lead. Photo by Amjad Jamal/IWMI-Pakistan

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