Effect of land use change and climate on surface runoff and water balance : the case of Mae Kam Mee Watershed, Northern Thailand | |
| Author | Thian Wittayawarakul |
| Call Number | AIT Thesis no.NR-08-14 |
| Subject(s) | Land use--Thailand--Phrae Water balance (Hydrology)--Thailand--Phrae Climatic changes--Thailand--Phrae |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Natural Resources Management, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. NR-08-14 |
| Abstract | This study examines the effect of land use change and climate on the surface runoff and water balance in the Mae Kam Mee watershed, Northern Thailand. The natural resources within the watershed encounter by the anthropogenic activities as deforestation, urban sprawl, agricultural expansion, inappropriate and unsuitable land use, population growth and national economic expansion. During few decades, the Mae Kam Mee watershed has met the natural disaster as floods, droughts and landslide. The water deficit has been taking place within the watershed influencing the agricultural production and other uses. In this study, the Landsat Thematic Mapping (TM) images were used for preparing the land use maps to detect the transition of land use of 1989 to 1999 and 1999 to 2006. Then, the SCS curve number method and water balance equation were used to estimate the surface runoff and change in soil moisture storage (~SM), respectively. It was found that there were the two trends of land use conversion during 1989 to 2006 which are forest-to-cropland scenarios and cropland-to-urban scenarios. The former occurred at the upper part of the watershed which the upland shifting cultivation has been taking place by the ethnic communities. The natural forest and shrub-land has gradually decreased from 78.66 per cent in 1989 to 54.60 per cent in 2006. The results of land use change detection shows 6.82 per cent of forest area had been converted to cropland during 1989 to 1999. Moreover, 20.10 per cent of forest area had also changed to cropland during 1999 to 2006. The latter occurred at the lower part of the study area which most of area have been converted from rice fields to residential area. At 4.96 per cent of paddy field and 1.54 per cent of cropland had been transformed to residential area during 1989 to 1999 and then, they had been changed 48.98 per cent and 32.62 per cent, respectively during 1999 to 2006. These situations are the representative of transition of land use/cover in the northern Thailand and the Southeast Asia. The meteorological data were collected from the Meteorological Department which were used as climate inputs. The surface runoff has gradually increased from 42.87 cm in 1989 to 46.14 cm and 76.15 cm in 1999 and 2006, respectively. The results of surface runoff estimation using the lowest, highest and average rainfall show the relationship of rainfall-runoff that the amount of rainfall is the major factor influencing a rise of surface runoff. While the temperature impact on the surface runoff can be negligible because there is no relationship between them in this study. The land use conversion and surface runoff relationship also examine that the transition of land use/cover among 1989, 1999 and 2006 influenced the changes in surface runoff in this watershed. The results of ~SM estimation show the water deficit in the watershed; however, it seemed as a rise of amount of rainfall can cause an increase in ~SM. Nevertheless, there are two more partition influencing the ~SM which are surface runoff and AET but these variables are controlled by the land use attributes and climate. The constant rainfall and land use data were used to examine the effect of both factors on the surface runoff and ~SM. The land and water conservation and management are needed for carrying out the natural resources problems in the watershed which has been undergoing the overland flow and water deficits. The water allocation system is useful to distribute the water supply for agricultural production and other uses in wet and dry season. The sustainable land use approaches are needed to adjust the natural resources development and management in the watershed. |
| Year | 2008 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. NR-08-14 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Development and Sustainability (DDS) |
| Academic Program/FoS | Natural Resources Management (NRM) |
| Chairperson(s) | Shrestha, Rajendra Prasad |
| Examination Committee(s) | Clemente, Roberto S.;Perret, Sylvain Roger |
| Scholarship Donor(s) | RTG fellowship |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2008 |