Our laboratory conducts international collaborative research with universities and researchers overseas, aiming to contribute to environmental improvement in other countries by applying the knowledge and simulation models developed through our previous research. We work together with students who are interested in international activities and motivated to contribute to solving environmental problems around the world.
Aquatic Environment Research Project in Tonle Sap Lake, Cambodia
Tonle Sap Lake is the largest freshwater lake in Southeast Asia, extending approximately 200 km. The lake plays an essential role in supporting the livelihoods and culture of local communities. Extensive rice fields surround the lake, and its fisheries are said to supply more than half of the protein consumed in Cambodia.
Cambodia has distinct wet and dry seasons, and Tonle Sap Lake exhibits unique hydrological characteristics. During the dry season, the lake becomes very shallow, with water depths of only a few meters. In contrast, during the wet season, water flows back into the lake from the downstream Mekong River, expanding the lake’s surface area to approximately six times its dry-season size.
In recent years, concerns about deteriorating water quality have been growing due to increasing industrial wastewater discharge, the use of chemical fertilizers and pesticides, and domestic wastewater from hundreds of thousands of people living in floating houses and communities on the lake. These factors contribute to eutrophication, a process characterized by increasing concentrations of nutrients such as nitrogen and phosphorus in lake water.
Unfortunately, Cambodia’s history of civil conflict has limited the development of environmental monitoring systems and the availability of trained engineers and researchers.
In this project, we collaborate with researchers from Cambodian universities to conduct field observations and collect fundamental environmental data. By applying the knowledge and experience gained from our previous research on aquatic environments in Japan, we aim to better understand the hydrological and environmental conditions of Tonle Sap Lake and develop a numerical flow simulation model that can support its future environmental management.
The animation below shows results obtained using our newly developed flow simulation model. By employing GPGPU technology to accelerate numerical computations, we can simulate water flow over an extensive area of approximately 200 km × 200 km for an entire year in just two hours.
The video below shows our field observations at Tonle Sap Lake. You can see a floating village consisting of houseboats.