Land Use Adaption to Climate Change in the Vu Gia–Thu Bon Lowlands: Dry Season and Rainy Season

Abstract

Coastal areas of Central Vietnam are densely populated and characterised by an intensive use of land. Located in this region, the lowlands of the Vu Gia - Thu Bon (VGTB) river basin witness intensive ongoing changes in land use, hydrology and water resources management due to climate change and socioeconomic development. The VGTB lowlands feature distinctive dry and rainy seasons with accordingly human activities and hazards. Climate change and socio-economic development is influencing and intensifying hazards in both seasons. The two major hazards saltwater intrusions into the river system and fluvial floods are the subject of this chapter. Saltwater intrusions in the dry season are a risk for agriculture and water supply while floods in the rainy season are a risk for settlements and infrastructure in the rainy season. The dry and rainy season are analysed separately. Applicable measures are identified, which prevent an increase of risks and if possible reduce risk. GIS and hydraulic-numerical model based risk-assessment approaches are applied for the hydrological system of the VGTB lowlands in both seasons. The risks are evaluated for the current state and future scenarios. The investigated scenarios include impacts of climate change and land use change as well as regional and local measures. The key results for each season include the evaluation of the method and the identified measures.