| Multipurpose projects


South Korea has a temperate monsoon climate, with approximately 60–70 % of its annual precipitation falling during the summer monsoon and typhoon. This highly seasonal rainfall causes pronounced fluctuations in reservoir water levels and thermal stratification, affecting GHG emission dynamics. These three major river basins exhibit distinct geological and hydrological characteristics that may influence GHG emissions. The results found that all systems acted as carbon sinks before impoundment but became net emitters after dam construction. The Daecheong reservoir had the highest net GHG emissions, mainly due to significant forest cover loss before impoundment. After reservoir construction, emissions were primarily attributed to surface CO2 diffusion, followed sequentially by CH4 diffusion, degassing, and bubbling. Higher total phosphorus concentrations are strongly linked to increased emissions, suggesting that improving water quality can help reduce emissions. The authors say their results underscore the importance of linking reservoir GHG assessments with land-use planning and water quality control. The study provides practical guidance for dam managers and policymakers seeking to improve operational performance while minimising climate impacts through integrated upstream-downstream management strategies.


Potential in Rwanda Rwanda is a rapidly growing country and ranks among


the fastest-electrifying countries in Sub-Saharan Africa. With agriculture accounting for a quarter of national GDP, improving productivity is essential due to limited opportunities for expansion of cultivated land. Access to clean drinking water is another challenge the country faces. According to UNICEF, just 57% of the population has access to clean drinking water within a 30-minute distance from their homes. Expanding access to both electricity and clean drinking water remains a central developmental challenge and recent research has focused on a case study in the Eastern Province’s Tabagwe to address this. The investigation looked at the feasibility of implementing a multipurpose dam system to support irrigation while simultaneously enabling electricity generation and water purification through an integrated infrastructure. A linear optimisation model was developed to identify the most cost-effective setup of this multipurpose dam. The result showed that a multipurpose dam


providing irrigation, electricity, and clean water could be a viable solution for Tabagwe. These functions can be adapted to local needs and economic conditions. The most advanced configuration offered electricity access of 1kWh capacity, available for at least eight hours per day, sufficient to power appliances such as a refrigerator, fan, or television.


Optimisation The problem of parallel and series use of multiple and


multipurpose reservoirs in the dams of Iran’s Karun watershed has been the focal point of a recent study. Optimising the operations of dam reservoirs with the objective function of minimising shortages and maximising hydropower production was modelled and solved using training data.


References


Greenhouse gas emissions and footprint analysis of multi-purpose dam reservoirs in temperate climates: Case study from South Korea Kyeongseo Min, Sungjin Kim, Sewoong Chung. Renewable and Sustainable Energy Reviews 225 (2026) 116143. https://doi.org/10.1016/j. rser.2025.116143


A Viability Analysis of Multipurpose Dam System in Rwanda Renewable Energy for Irrigation, Electricity and Clean Water by Amelia Bergum Alida Nilsson. Master’s thesis 2025. Department of Electrical Engineering Division of Electric Power Engineering Chalmers University of Technology Gothenburg, Sweden 2025.


Optimizing the operation of series and parallel reservoirs using the neutrosophic environment: A case study of the Karun watershed Seyyed Ebrahim Rezai a, Ahmad Sharafati, Seyyed Ahmad Edalatpanah and Saeed Jamali. AQUA — Water Infrastructure, Ecosystems and Society Vol 74 No 1, 92. doi: 10.2166/aqua.2024.359


The Karun-e Bozorg is one of Iran’s river watersheds. Its main river is the Karun, which covers an area of 67,257km2, and five dams are in series across the basin. Karun-4, Karun-3, Karun-1, and Godar-e Landar dams have the primary purpose of hydropower, while the Gotvand dam has the primary purpose of agriculture and a secondary purpose of hydropower. These five dams are operated in parallel with the Dez Dam on the Dez River to supply water for agriculture and hydropower. This research shows how the evolution of artificial


intelligence has resulted in the development of problem-solving techniques and the emergence of optimisation algorithms which have greatly improved the operational performance of reservoirs.


Above: Lake view from mountain top in Rwanda


Below: Capti Karun 4 Dam in Iran


www.waterpowermagazine.com | November 2025 | 23


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