Nexus Publication: An impact analysis of population growth on energy‐water‐food‐land nexus for ecological sustainable development in Rwanda

Authors: Katundu Imasiku & Etienne Ntagwirumugara

Published: August 2019

Read Full Open Access Article: Imasiku, K., & Ntagwirumugara, E. (2020). An impact analysis of population growth on energy‐water‐food‐land nexus for ecological sustainable development in Rwanda.


While agricultural activities are a major drain on water resources in Rwanda, its high population growth continually escalates energy–water–food–land nexus pressures. With 13.03 million inhabitants on a 26,336 km2 area which translates to be 495 inhabitants per km2, Rwanda has the second‐highest population density in Africa because of its high annual population growth rate of 2.95%. Access to clean drinking water, energy, and food to meet the demographic needs in Rwanda are fundamental, but this is unlikely to be the case by 2050 due to the anticipated land scarcity. Land stress is endangering energy, water, and food security, and this works against ecological sustainable development. This research analyzed the ecological balance of human activities in Rwanda and how policymakers have increasingly emphasized on energy–water–food nexus sectors separately without integrating land usage and population growth which poses an even more critical situation if left unattended to. The research study recommends the Multi‐Scale Integrated Analysis of Societal and Ecosystem Metabolism (MuSIASEM) method as being appropriate to support the transition toward a sustainable economy because it is used to optimize resources, generate focused decisions, actions, investments, and policies that would combat nexus pressures and promote ecological sustainable development.

Introduction Segment

To date, many studies have been conducted in Rwanda concerning energy–water–food nexus issue which has all pointed to land as being a critical factor in the energy–water–food nexus sectors. In 2017, Josefine Axelsson and Emelie Johnson of KTH Royal Institute of Technology presented in their research, on the Food–Water–Energy nexus assessment in Rwanda highlighting that the Climate, Land, Energy, and Water (CLEW) technique that integrates different models can investigate land, energy, and water use developments while considering climate change impacts. The CLEW is a framework for integrated assessment of resource systems and modeling using quantitative tools like LEAP1 (Long‐range Energy Alternatives Planning System) or OSeMOSYS2 (Open Source Energy Modeling System) for energy, WEAP3 (Water Evaluation and Planning System) for water use while the AEZ4 (Agro‐Ecological Zones) is for land use. Though thorough work is being done on the Energy–Water–Food nexus sectors, these sectors will according to empirical evidence have the climate change affect the water availability but not dramatically (Josefine & Emelie, 2017). Further studies on the Rwanda Energy–Water–Food sectors by Oliver W. Johnson et al. of Stockholm Environment Institute in Sweden explored the water–energy–food nexus in Rwanda’s Akagara Basin in 2018. Both studies showed that while hydropower in Rwanda will continue to play a significant role in the electricity mix until 2050, it depends on water availability and rain patterns (Johnson et al., 2018). The expected water scarcity demands a thorough water management system in Rwanda. These previous studies show that the outcome of their studies is not conclusive because of several land assumptions made on the soil types and that the land usage exclusion warrants the need for more inclusive studies. The following are some expected challenges by 2050 if Rwanda takes no measures (Johnson et al., 2018);

  • Over‐exploiting land through human activities reduces the ability for water to run off and this causes floods.
  • Unplanned human settlement causes landslides. In 2018, Landslides in Rwanda killed at least 18 people in May 2018, bringing the death toll to 200 by the end of 2018 (Rwanda landslides after heavy rain brings 2018 death toll to 200, BBC News, 2018).
  • At a growth rate of 2.95%, the population will increase to 32.1 million by 2050 while the total land area will remain 26,338 km2 (Why Rwanda’s population is increasing so fast). This scenario will increase the water, food, and energy consumption in Rwanda and consequently lead to the pressure on land, biomass resources, and water ecosystems because of the high population, adversely changing the climate.
  • A further reduction of the land size is expected because a segment of the future energy production is expected to be generated from peat. Rwanda plans to utilize approximately 100,000 ha of wetlands reserves and harvest the carbonized vegetable matter in Rwabusoro, Akanyaru, Murago, Gihitasi, Mashya, Gishoma, Rucahabi, Cyato, Cyabararika, Nyirabirande, Kageyo, Kaguhu, Mashoza, Gasaka, Bahimba, Bisika, Rwuya, Nyabigongo, and Rugeramigozi (Rwanda Energy Sector Review and Action Plan, African Development Bank Group, 2013). This activity also poses a major threat to wetland ecosystems.

However, planning water, food, and energy projects without considering land usage in Rwanda will lead to land stress because water, food, energy, and land sectors are interdependent. The conclusions made from the electricity, food, and water model calculations in previous studies are that all these sectors have multiple and complex social, economic, and environmental effects on Rwanda. Land usage and scarcity was considered as a possible extension of their studies. (Johnson et al., 2018; Josefine & Emelie, 2017; Strategic Plan for the Transformation of Agriculture in Rwanda – Phase II (PSTA II), 2009). It is with this background that our study aims at investigating the effects of disconnected approaches of dealing with energy–food–water nexus projects in isolation with land usage and plans an integrated approach to these issues.

The study illustrates the basic methods and suggests practical tools which the Rwandan Government can utilize, through its implementing agencies to account for the energy–water–food–land nexus sectors in an integrated manner that provides a clear nexus status for sound decision making. The proposed approach offers a multiscale and integrated assessment methodology that presents a comprehensive accounting approach of resource management sustainably to achieve ecological sustainable development (ESD) in Rwanda. Ecological sustainable development is necessary to improve the quality of lives for many Rwandans today and in future while maintaining an ecological balance of all‐natural and socioeconomic activities of man without regard to the cost implications attached to environmental well‐being (Ecological Sustainable Development, Aron Brown Gas Project EIS, Aron Energy, 42626960/G/Rev A, 2012).

© 2019 The Authors.