Development of a Regional Hydrological Platform and a Water-Energy-Food Nexus Model for the Amazon Basin

The Amazon Basin, the world’s largest watershed, plays a critical role in regulating the global water and biogeochemical cycles. Given its importance, addressing the region’s growing environmental, social, and economic challenges requires an integrated approach to sustainable development. This study documents the development and application of an integrated water-energy-food nexus model to support the Amazon Cooperation Treaty Organization (ACTO) and the Inter-American Development Bank (IADB) in evaluating infrastructure and policy interventions in the basin. The nexus model allows for multi-sectoral analysis, providing a framework to quantify interdependencies and trade-offs across water, energy, and food systems in face of climate change, land-use dynamics, and socioeconomic uncertainties. 

Three scenarios: Business-as-Usual (BAU), “Extractive,” and “Sustainable”, are analyzed. The BAU scenario serves as a baseline, while the Extractive scenario maximizes natural resource exploitation through hydropower and irrigation. In contrast, the Sustainable scenario emphasizes resource preservation, limiting deforestation and promoting yield improvement policies. These intervention scenarios are assessed under uncertainty scenarios derived from stakeholder consultations, combining climate change and socio-technical factors. 

The key findings of the study are: 

• The Amazon region faces minimal trade-offs between water uses due to its water abundance and limited consumptive water activities, such as irrigation, which only accounts for 3.9% of cultivated land. Access to water is more constrained by financial, institutional, or quality issues rather than water availability. 

• Although the Amazon might experiences significant seasonal changes in precipitation (up to -50% in some months), its high rainfall and the timing of dry seasons minimize climate change impacts on seasonal crops. However, temperature changes and "savannafication" could reduce forest areas and, consequently, precipitation. Livestock production, dependent on year-round grazing, might face greater risks.

• Hydropower, despite water abundance, remains vulnerable to climate variability. Most planned Amazonian plants are run-of-the-river systems, relying on past climate conditions. Climate change could reduce hydropower output by up to 10%, particularly during already dry months when demand peaks. This could diminish hydropower’s value, especially in a future energy mix reliant on intermittent sources like wind. 

• Greenhouse gas (GHG) emissions in the Amazon are predominantly linked to land-use changes. Particularly deforestation for cattle ranching and crop cultivation, which account for 50-80% of emissions under different scenarios, while direct cattle emissions contribute by 10-30%. Addressing GHG reductions requires a holistic approach, given the inter-sectoral trade-offs, especially concerning biofuel crop expansion, which competes with food crops and forests, is sensitive to climate change, and impacts the energy system's emissions. 

The study highlights the necessity of integrated planning to optimize resource use, mitigate trade-offs, and promote synergies among sectors. It also emphasizes the importance of addressing uncertainties and ensuring equitable, transboundary decision-making across the basin’s eight countries. The findings provide valuable insights for ACTO, IADB, and national governments to guide feasibility studies and prioritize investments for the Amazon River Basin.