Effect of land use change on runoff and sediment yield in the Northwest of Vietnam | |
| Author | Ngo Thanh Son |
| Call Number | AIT Diss. no.NR-15-03 |
| Subject(s) | Land use--Vietnam, Northwestern Climatic changes--Vietnam, Northwestern |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Natural Resource Management, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. NR-15-03 |
| Abstract | Rapid population growth, together with economic development, is considered a main factor of land use and land cover change in the Northwestern Vietnam. Increas ing the food demand which in turn is propelled by rapid population growth catalyzed conversion of several parts of the forest to agricultural land; lack of regulation to protect and sustai nable use of natural resource on the other hand led to exploitation of timber and reduction of natural forest cover. The expansion of field crops and paddy land was due to population pressure, increasing food demand and transition from subsistence and plan ned economy towards market orientation. D e forest ation on the steep slopping land and their uses for agricultural purpose is predicted to intensely increase soil erosion risks , which carries large amount of nutrient and diffuses sediment inputs to surface w ater. In reality, the land use change is still a serious problem that it seems beyond control for the time being . The study was conducted in the Northwest region of Vietnam including lower Da River Basin and upper Ma river basin where forest resource is t he most abundant but usually located on the slopes. It is one of the most disaster - prone regions , which suffer from typhoons, tropical storms, drought, landslides, soil erosion, and forest fires. The overall objective is to evaluate the effect of land use / land cover change on runoff and sediment yield and to estimate its likely effect on ecosystem functions in the future using RS, GIS and SWAT based methodology. H ousehold survey was combin ed with biophysical data of land use /land cover change to develop the scenarios of land use . It helps evaluating the influence of land use and climate scenarios on changing the future runoff and sediment yield. The outcomes of the study point ed out that changes in the type of land use of Da river basin of Hoa Binh provinc e between 1995 and 2005 from forest to field crop and urban area st rongly contributed to increase in the average annual runoff from 182.5 mm to 342.7 mm and sediment yield from 101.3 ton - 1 ha to 148.1 ton - 1 ha. Between 2005 and 2010, a decrease of both run off (from 342.7 mm to 167.6 mm) and sediment yield (from 148.1 ton - 1 ha to 74.0 ton - 1 ha) was due to the expansion of forested area and application of soil conservation practices. The same results was observed in Da river basin during that period , the ind ividual land use /land cover change in the upper Ma river basin increased surface runoff and Evapotranspiration (ET) considerably by 10.4% and 15.4% , respectively, while decreased lateral flow, base flows, percolation, and water yield changed by - 8.7%, - 14. 1%, - 13.8%, and - 62.9% , respectively . I ncrease d precipitation in the study area led to significant increase of all hydrological components such as surface runoff by 40.2%, lateral flow (13.3%), base flow (19.1%) percolation (18.8%), and water yield (23.2%) . The combin ation impacts of land use /land cover and climate change resulted in all hydrological components increas ing significantly including surface runoff (46.3%), lateral flow (2.2%), base flow (0.2%), percolation (0.3%), ET (8.2%) and water yield (10. 4%). An attribution to these changes was deforestation and agricultural expansion that took place between... |
| Year | 2015 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. NR-15-03 |
| Type | Dissertation |
| 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) | Shivakoti, Ganesh P. ;Shrestha, Sangam ;Nguyen Duy Binh; |
| Scholarship Donor(s) | Ford Foundation Vietnam ;Asian Institute of Technology Fellowship; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2015 |