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The Nexus Methodology

Water, energy, food and ecosystems are so strongly interlinked that actions in one sector will impact the other. Taking the interlinkages into account can help to make resource management more sustainable, reduce negative intersectoral or environmental impacts and to make policies more coherent. A set of assessments of the water-food-energy-ecosystems nexus  have been carried out in several transboundary river basins using a methodology developed for the purpose under the Water Convention. The objective is to give attention to the interlinkages and their intersectoral synergies to foster transboundary cooperation and increase resource efficiency. An overview of the nexus methodology, which was adapted and improved during the assessments, is made available here. It includes principles, steps and the flow of information of the methodology. The methodology is applicable to diverse transboundary basins and aquifers.

The guiding principles were to make the assessment based on a participatory process, contributing to capacity building of stakeholders from all participating countries and sectors. It counts on local knowledge mobilization, a sound scientific analysis and the collective effort reflecting a broad range of views.

The six steps of the methodology comprise of defined tasks that are either carried out by analysts and authorities in desk studies or by the stakeholder during workshops.

Step 1: The needs of the population in the basin as well as the national needs that rely on the basin are identified. This develops an understanding of the basins socioeconomic context, its resource base and the governance context.

Step 2: The identified needs are associated to sectors and institutions. Hence the key sectors and stakeholders are identified. They can contribute with their knowledge and power to take action.

Step 3: The key sectors are analysed applying the Drivers-Pressures-State-Impacts-Response framework. The analysis is further refined in the first workshop.

Step 4: In the first workshop, stakeholders identify and detail issues between sectors while considering the sectoral plans and linkages to other sectors.

Step 5: Still in the first workshop a nexus diagram is drawn collectively. It includes the nexus components water, food, energy, ecosystems and all the identified linkages.


Step 6: Possible solutions to the most pressing intersectoral issues are identified. Stakeholders identify various solutions such as, land use management, cooperation agreements, policy solutions, infrastructure projects or economic instruments.

Information exchange is a crucial part of the process when authorities, stakeholders and analysts carry out the steps of the assessment. The figure shows how (a) key documents are exchanged between stakeholders, authorities and analysts for desk studies and (b) how information is passed to the workshops.

Looking beyond this overview, the nexus assessment methodology uses a broad set of indicators and different fit-for-purpose tools depending on the intersectoral issues analysed. Several nexus tools and approaches have been developed to assess the nexus at different scales and for different purposes, and could be considered for detailing a scoping level assessment of the kind carried out using the methodology developed under the Water Convention. These include: (1) dialogues; (2) mapping; (3) scenarios; (4) extended systems analysis; and (5) institutional analysis. A cursory overview can be found here.

Further information on the methodology and experience from its application (until 2018) can be found in this publication:

"Methodology for assessing the water-food-energy-ecosystems nexus in transboundary basins and experiences from its application: synthesis"

For a brief visual overview of the methodology, refer to this summary.

Case studies

Nexus assessments using the methodology have been carried out in several basins. Related information and documentation can be found here.

A peer reviewed technical article on the nexus assessment methodology.