Assessing land use variation on water discharge in Vu Gia - Thu Bon watershed

Nguyễn Thị Hồng, Nguyễn Thị Bích, Lê Hoàng Tủ, Nguyễn Thị Huyền, Nguyên Kim Lợi

Land is a precious natural resource. Currently, the requirements of economic and social development make pressure on the land use variation. The growth of population, the expansion of cities and urban areas, the economic development, and other issues have been making a huge impact to the status of land use. The study takes application of GIS and the model of Markov chain to calculate the land use change during the period from 2005 to 2010 on the Vu Gia - Thu Bồn basin, Quảng Nam province. Besides that, the study also considers about the effect of land use change to water discharge by using Soil and Water Assessment Tool model (SWAT). Analysis results showed that within 5 years (2005-2010), the area of forest land increased 63,104.82 ha (346.44%), the area of resident land increased 62,258.35 ha (341.79%), and the area of unpurposed land reduced 72,336.9 hectares (397.12%). Simulation result of annually stream flow in Vu Gia - Thu Bôn watershed increases 0.97 times in the dry season and decreases 1.3 times in the rain season. Because of the changing in land cover so that affects to water discharge especially nsing of land ị́rest. The main reasons leading to the increase of the forest area are people's awareness of the economic beneíĩts brought by the forest, and the supports from the programs or projects of local government and intemational orgamzations. In addition, the ́ncreasing of forest land also contributes in control flood in the rain season.

Người biên tập: GS.TS Trương Xuân Luận.