Evaluation of climate and land use change impact on hydrology of the Songkhram River Basin, Thailand | |
| Author | Acharya, Dhiraj |
| Call Number | AIT Thesis no.WM-17-16 |
| Subject(s) | Hydrology--Thailand--Songkhram River Basin Climatic change--Thailand--Songkhram River Basin |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. WM-17-16 |
| Abstract | Land use change and climate change are the major factors of hydrological variation in any river basin. This study quantifies the contribution of the climate change and land use change impact in runoff variation in Songkhram River Basin in past and evaluate s the impact due to future land use change in hydrology. Long term trends of hydroclimatic data were examined using Mann - Kendall test and rainfall - runoff double mass curve and Pettitt test were used for the change point detection. Soil and Water Assessment Tool ( SWAT ) model was used for hydrological simulations and quantification of the impact of climate change and land use change in past 25 years (1990 - 2014). The results show that Songkhram River Basin has been experiencing a significantly increasing (p < 0.05) rainfall trend and planted trees and range land use are increasing in past at the expenses agricultural land and forest. Statistically significant change point in runoff variation was not found from Pettit’s test hence 2003 was assumed as the change point. A comparison between 1990 - 2003 and 2004 - 2014 showed 21 % and 79 % contribution of land use and climate change respectively in surface runoff increase in Songkhram River Basin. Projected land use maps, using semi distributed probabilistic Dyna - CLUE model, for economic scenario, forest conservation scenario, and food security scenario in future (2100) were used for evaluating future land use change impacts on hydrology and water balance in Songkhram River Basin . Economic and forest conservation scenarios were found effective in reducing flood in comparison to food security scenario in future . Evapotranspiration was found to increase significantly (p < 0.05) in all three scenarios with higher increment in wet season. Results indicate significant decrease in surface runoff in economic and forest conservation scenario in dry season (p < 0.05) but increase in wet seasonal surface runoff in food security scenario and very less decrement in dry season compared to other scenario. Baseflow is expected to reduce significantly in food security scenario and water yield is going to decrease in all three scenarios with significant decrease in dry season compared to wet. Water yield reduces less in food security scenario compared to other two scenarios. The results of this study shows that land use change, though not as significant as climate change, plays a vital role in hydrological variations and it helps the water managers and planners and policy makers to develop strategies to deal with the implication of possible future land use impact on hydrology. |
| Year | 2017 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WM-17-16 |
| Type | Thesis |
| 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) | Shrestha, Rajendra Prasad;Andriyas, Sanyogita;Supattana Wichkul |
| Scholarship Donor(s) | Building Capacity & Strengthening Community Participation for Water Resources Management and Wetland Ecosystem Restoration in Context of Climate Change in Lower Songkhram River Basin. HSBC;AIT Fellowship |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2017 |