Author(s): Binh Quang Nguyen; Sameh A. Kantoush; Thanh-Nhan-Duc Tran; Doan Van Binh; Ngoc Duong Vo; Mohamed Saber; Tetsuya Sumi

Linked Author(s): Mohamed Saber, Tetsuya Sumi

Keywords: Hydrological responses; Land Use/Land Cover (LULC); Dam development; SWAT; Vu Gia Thu Bon River basin

Abstract: The Vu Gia Thu Bon River (VGTB) basin is an important watershed, serving as a primary source of drinking water and supporting agricultural production in Central Vietnam. However, the potential hydrological responses of anthropogenic activities, such as land use/land cover (LULC) change and dam development, have not been comprehensively quantified in recent decades. Therefore, this study aims to assess the long-term hydrological impacts of anthropogenic activities in the VGTB River basin. LULC datasets are obtained annually from the Regional Land Cover Monitoring System (RLCMS) by SERVIR-Mekong for 2010–2018. Streamflow data are collected from observations and the results of the Soil and Water Assessment Tool (SWAT) hydrological model spanning 42 years (1979–2020). The hydrological responses during 2011–2020, when cascading hydropower dams were constructed, are quantified and analyzed using the SWAT model. Our findings show that: (1) dam development and LULC changes are identified as the primary drivers of flow alterations upstream; (2) water transfer resulted in decreased flow and increased saltwater intrusion in recent years, especially in the VGTB downstream part; (3) the significant impact could be found as the decline in agricultural production and an expansion of bare land. This study comprehensively explains the hydrological responses to hydraulic infrastructure effects in the VGTB River basin. The findings will serve as a scientific foundation for future management plans of stakeholders and decision-makers concerning water resource management in the region.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p1339-cd

Year: 2023