Integrated assessment of watershed health under future climate change, land use change, and water use change scenarios : a case study of the Nan river basin in Thailand | |
| Author | Talampas, Shella Ira |
| Call Number | AIT Diss. no.WM-25-03 |
| Subject(s) | Watersheds--Thailand--Nan River Basin--Management Climatic changes--Thailand--Nan River Basin Land use--Thailand--Nan River Basin |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Water Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | This study introduces the Integrated Watershed Health Assessment Framework (IWHF), a comprehensive tool for evaluating watershed conditions and guiding management strategies. The IWHF employs global expert opinions and the Analytic Hierarchy Process (AHP) as decision management tools to define criteria for weighting key watershed health attributes, prioritizing ecological factors (48.8%), followed by economic (21.9%), socio-cultural (16.9%), and policy (12.4%) considerations. The IWHF was applied to the Nan River Basin (NRB) in Northern Thailand to assess 17 sub-basins. Hydrological modeling using the Soil and Water Assessment Tool (SWAT) and geospatial analysis (GIS) identified well-functioning sub-basins and highlighted areas requiring improvements in ecological conditions, socio-cultural engagement, economic stability, and policy frameworks. A vulnerability analysis, integrating CMIP6-GCM climate projections under SSP2-4.5 and SSP5-8.5, Dyna-CLUE land-use projections, water use scenarios, and GIS analysis, revealed increasing vulnerability over time. While most sub-basins remained stable in the Near Future, several transitioned to vulnerable states in the Mid and Far Future due to intensifying stressors. Sub-basins in the Lower NRB, dominated by agriculture and expanding urban areas, were the most susceptible due to rising impervious surfaces, shifting water use patterns, and climate change impacts. To guide conservation and restoration, sub-basins were classified into four management groups: Protect, Protection Priority, Restoration Priority, and Restore. Resilient sub-basins were designated for conservation, while less resilient ones required immediate intervention to prevent long-term degradation. The study recommends adopting climate-resilient agriculture, improving water conservation in agriculture and industry, and strengthening governance mechanisms. Integrating digital monitoring tools and promoting research innovation will be crucial for sustaining watershed resilience through adaptive management. These strategies provide valuable insights for policymakers and stakeholders to support the long-term sustainability of the NRB and other vulnerable watersheds. |
| Year | 2025 |
| Type | Dissertation |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Shrestha, Sangam |
| Examination Committee(s) | Thammarat Koottatep;Shanmugam, Mohana Sundaram;Natthachet Tangdamrongsub;Khadka, Dibesh |
| Scholarship Donor(s) | University of Science and Technology of Southern Philippines – Cagayan de Oro (USTP-CDO) |
| Degree | Thesis (Ph.D.) - Asian Insitute of Technology, 2025 |