Nexus tools to evaluate water, energy, food, policies in the Ganges Basin

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Nexus tools to evaluate water, energy, food, policies in the Ganges Basin

By Vartika Singh, Mohammad Faiz Alam, and Ruchi Sharma

India plays a pivotal role in global agriculture, being the second largest producer of significant crops like rice, wheat, sugarcane, pulses, and cotton. Within India, the Ganges River Basin is critical for food security both nationally and in the wider region. It provides over one-third of available surface water in India, supports about 43 percent of the country’s population, and contributes more than half of national water use.

The Ganges Basin is characterized by multiple challenges. In its western region, high agricultural productivity has come at the cost of severe environmental degradation including groundwater overexploitation, soil erosion, and pollution. Conversely, the basin’s eastern region is characterized by low productivity, with relatively little investment in irrigation and other inputs, and underutilization of groundwater resources. This area is also prone to flooding.

Creating assessment tools using a systems approach

The contrast between the two regions of the Ganges Basin highlights the need for tailored policy analysis at the water–energy–food–ecosystems (WEFE) nexus. Such analysis recognizes that WEFE sectors have many interconnections and interdependencies, with decisions taken for one sector resulting in externalities (positive or negative) in the others. Effective management of these interconnections is vital for achieving United Nations’ Sustainable Development Goals linked to clean water and sanitation, zero hunger, affordable and clean energy, and climate action.

A recent review of policies and programs on water, energy, food, and ecosystems in India showed that multiple policies have been enacted during the last four decades. However, these policies rarely consider impact on other sectors, and associated programs significantly overlap in terms of objectives and goals. For this reason, since 2022, the CGIAR Initiative on NEXUS Gains has been developing methodologies and tools to enable the assessment of WEFE policy scenarios for synergistic action.

NEXUS Gains is carrying out integrated modeling assessments – taking a systems approach to identify critical linkages and interdependencies, and feedback loops and trade-offs at different levels. For the Ganges Basin, the initiative has combined hydrological models (SWAT and MODFLOW) with a food model using the Food, Agriculture, Biodiversity, Land use and Environment (FABLE) Calculator, to simulate different WEFE scenarios. The results enable analyses of the large-scale impacts of alternative interventions, thereby supporting policy and decision-making processes.

To ensure that scenarios and interventions are driven by Indian policy makers and practitioners, NEXUS Gains held a workshop on “Integrated Modeling of the WEFE Nexus in the Ganges Basin” in December 2022. The workshop convened diverse stakeholders – including representatives from central and state governments of India and non-government organizations, and researchers – to address challenges and outline a roadmap for nexus-based interventions. The participants co-developed WEFE policy scenarios for simulation, and proposed interventions such as improving water-use efficiency, transitioning to solar energy, promoting crop diversification, and increasing forest cover.

Stakeholder workshops, 2022 ( top ) and 2024 ( bottom ), held in Delhi, India.

Developing a dashboard to generate and visualize scenarios

To translate proposed policy scenarios into model inputs, it is essential to address three key aspects. First, where an intervention should take place, such as areas with overexploited groundwater resources. Second, how much change is required, such as increasing irrigation efficiency by 10 percent. Third, what type of intervention is planned, such as irrigation expansion involving groundwater or surface water.

To aid this decision-making process, NEXUS Gains has developed an online dashboard designed for policymakers and researchers in the Indo-Gangetic Basin. This dashboard serves as an interactive modeling tool that enables users to generate and visualize WEFE scenarios. It does this by integrating data from WEFE sectors – such as data on irrigation sources, energy sources, cropping patterns, groundwater development, and yield gaps – enabling users to craft tailored intervention scenarios.

For example, users can determine where irrigation should be expanded, and identify suitable water sources based on key indicators. The dashboard also supports the generation of scenarios for irrigation efficiency improvements and groundwater recharge management. At the same time, users can view changes in the consumption of key food groups across specific scenarios targeted towards the adoption of healthy diets, reduced water use, and increased crop yields. Users can visualize datasets, download data, and focus their analysis on the entire Ganges Basin or specific states.

NEXUS Gains is developing capabilities to directly incorporate WEFE scenarios into integrated models. During a workshop held in Delhi in October 2024, the initiative showcased how the dashboard offers a comprehensive and interactive platform for evidence-based planning. Session participants discovered how the dashboard can be used to highlight often-overlooked interconnections within the WEFE nexus, and to identify the most appropriate locations for targeted interventions.

Incorporating the FABLE Calculator

A key component of the NEXUS Gains dashboard is the FABLE Calculator. This Excel accounting tool helps in evaluating possible outcomes of food and land-use systems for the period 2000 to 2050. With the help of multiple scenarios in this calculator, it is possible to test the impact of different policies on land-use systems. In the calculator, drivers like population growth, food demand, exports and imports, productivity, food waste, land availability, gross domestic product, and afforestation/reforestation can be modified through in-built scenarios that drive the model outputs.

The FABLE Calculator is an established country-level calculator that supports the preparation of policies related to the food system and land-use change. For its dashboard project, NEXUS Gains developed a basin-level calculator using data collected from states in the Ganges Basin. This calculator was calibrated with historical data for 2005, 2010, and 2015. Starting in 2020, scenario assumptions were applied to modify the future trajectory of parameters.

Outputs from the calculator include daily kilocalorie consumption of various food groups per capita across different scenarios until 2050. The scenarios implemented in the dashboard can therefore incorporate measures for sustainable transformation towards healthy diets among the population of the Ganges Basin. This shift in diets drives change in the calculator towards feasible land-use change for agricultural production. Inclusion of results from various other associated indicators, such as those for reducing greenhouse gas emissions, is currently under development.

Attached link

https://www.cgiar.org/news-events/news/using-nexus-tools-to-evaluate-water-energy-food-and-ecosystems-policies-in-the-ganges-basin-india

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