Author(s): Le V?N Chin; Nguyen Tuan Anh; Roberto Ranzi
Linked Author(s): Roberto Ranzi
Keywords: No Keywords
Abstract: In recent years, climate change together with socio-economic rapid development have caused water shortages for water supply to large cities and irrigation areas in many regions of Viet Nam. The rainy season (from June to October) provides 80%of the total annual rainfall, while the dry season is from November to May of the following year. Lack of sufficient water volumes occurs in many areas where the pressure of a fast increasing population (1%per year on average in the last decade in Viet Nam), and intensive agricultural and industrial users are causing major problems facing sustainable development. Day river basin actually includes the entire western area of the downstream Red river. The total area of the Day river basin is of 8.000 km 2 with a length of 245 km. Before 1934, Day River was a natural sub-branch of the Red river. From 1934 to 1937, the Day dam was built by French with the purpose of flood relief and drainage as well as controlling the diversion of flood of the Red river into the Day river. The total population in the Day river basin exceeds 8 millions inhabitants, including the Hanoi capital, Nam Dinh and other large towns. In order to assess water resources in the Day river basin under socio-economic development and climate change scenarios, a use of water demand and water balance equations was performed (Le, 2011). The results showed that climate change will have large impact on the agricultural water demand, reliability and security of water resources system in the Day river basin which means that the deficit in agricultural water demand will become greater when considering the impact of climate change on rainfed and greenhouses. Namely, by the year 2020, total water demand is expected to further increase by0.91%for medium IPCC emission scenario (B2) and 2.07%for emission scenario A2 relative to the reference scenario which takes into account socio-economic development only. By the 2050, it will increase by 2.6%and 3.07%relative to the socio-economic development scenario for medium emission scenario (B2), high emission scenario (A2) respectively.