Author(s): M. T. Vu; V. S. Raghavan; Q. K. Nguyen; S. Y. Liong
Linked Author(s): Quang Kim Nguyen
Keywords: Drought Projection; Regional Climate Model; Standardized Precipitation Index; Climate Change; Vietnam
Abstract: Central Highland, Vietnam, is an extremely important area for perennial plantations of different crops, with coffee as the main crop. Vietnam is the world’s second largest coffee exporter. As the area has experienced severe droughts from time to time, it is extremely crucial to assess how vulnerable the area to drought is in the coming decades. The study focuses on drought projection, due to changing climate, for the period of 2011-2040. The Standardized Precipitation Index (SPI) is computed based on the monthly precipitation for different observed and modelled datasets over the Central Highland during the period 1990-2005. Data from a total of 13 stations data were collected from the study region and used for benchmarking to compare against gridded observation data and two Regional Climate Models (RCMs). Various characteristics of drought across the study region are analysed using the spatial and temporal distribution, drought duration, frequency and deficit. The results show some uncertainties in observations and indicate promising use of climate models for climate studies. Drought trend seems to be more severe for low-lying areas as compared to higher altitude regions. A strong need for a dense network of observations is felt as they could constrain observational uncertainties in making model evaluations far better. The RCMs proved to be reasonable in assessing drought over the study area and can serve as good proxies over data sparse regions, especially in developing countries, for studying detailed climate features at sub regional and local scales. Future climate changes over the central highland have been thoroughly assessed by downscaling 3 different CMIP3Global Climate Models (CCSM3, ECHAM5 and MIROC-medres) using the WRF and PRECIS models under the A2 scenario over the future climate 2011-2040. This ensemble study suggests that drought is likely to be much more severe in the coming decades over this region. This provides essential information to policy makers to undertake necessary adaptation and mitigation measures.
Year: 2014