Author(s): Nga Pham Hong; Kaoru Takara; Lan Pham Thi Huong; Son Nguyen Hoang
Linked Author(s): Hong Nga Pham, Thi Huong Lan Pham
Keywords: Flood hazard; Inundation mapping; Climate change; DPSIR framework; Vu Gia Thu Bon basin
Abstract: Central Vietnam in known as being highly vulnerable to natural disasters. Moreover, due to the trend of increased weather extremes caused by global climate change, the vulnerability of coastal communities would be further exacerbated causing high risk of casualties and damages. On the other hand, being aware of the complication of the physical processes as well as socio-economic issues in such dynamic coastal area, this paper presents the combined application of three approaches, including modeling simulation, mapping and statistical analysis to obtain the understanding about the flood inundation pattern and potential risk to people living in the downstream of Vu Gia-Thu Bon (VG-TB) river system, Quang Nam province, Central Vietnam. In this procedure, first, calibration and validation of MIKE NAM and MIKE-11 was carried out by using data set of past typical flood events. Based on that, the floods of selected frequencies, i.e. 10%, 5%and 1%were simulated. With the support of Arc-GIS, the simulation result was visualized to produce inundation extent and inundation depth maps for corresponding frequencies. These maps show that the flood with lower frequencies does cause substantial increase of total inundation area but more critically, mainly the increase of deep water (above 1m). Such issue of concern is projected to be accelerated in the coming period as the region has experienced the undesirable climate changes, much wetter rainy season and drier for the rest of the year causing more frequent occurrence of extreme flood events. Furthermore, based on the flood depth maps and intensive field survey, major social, economic and environmental consequences were assessed qualitatively by using conceptual framework of modified DPSIR (Driver-Pressure-State-Impact-Response). These results are considered as primary information for local authority and people to understand potential risk of flood hazard in the area and thereby, to tailor effective flood disaster management plan in the long run.
Year: 2014