Đánh giá diễn biến hạn hán và phân cấp độ yếu tố tác động đến hạn thủy văn ở vùng đồng bằng sông Hồng - Thái Bình
Abstract
The Red-Thai Binh river delta covers an area of 14,784 km2, accounting for about 4.5% of Vietnam territory. The Delta is characterized by the political and economic importance with Hanoi capital and the second largest place for agricultural production and farming of the country. The implementation of irrigation infrastructure in the Delta has been quite complete; however, the Delta cannot entirely avoid the influence of droughts. In recent years, the Delta experienced large-scale severe droughts, lasting from 2003 to 2011 and causing negative impacts on life, socio-economy, and environment. Drought is classified as meteorological drought, hydrological drought, agricultural drought and socio-economic drought, in this study only consider the issue of hydrology. There are many factors that affect the hydrological drought, including the main factors and sub-factors, so it is necessary to identify and decentralize the impact of hydrological factors. The article presents the study results and proposes appropriate evaluation criteria drought classification based on hydrological indices including the flow deficit (Kth) index and the surface water supply index (SWSI). Based on the evaluation results regarding the variation of drought indices in time and space in combination with the analysis of typical causes that drive drought phenomenon, a hierarchy of impact factors has been established reflecting drought progression in this area.
Keywords: hydrological drought, Kth index, SWSI index, Red-Thai Binh river delta, rainfall, evaporation, temperature, streamflow.
