Analysis of Physical and Economical Flood Impacts on Residential Areas in the Bago River Basin of Myanmar

Abstract:

Recently impact of floods on residential areas is becoming greater due to increasing frequency and scale of the flood events in the river basin of many countries. Flooding in the residential areas can destroy residential houses and contents and even cause loss of life, and it also impacts on daily life of the people living in the flood prone areas, which limits their living conditions as well as their capabilities of preparedness, response, and recovery to future floods. Therefore, analysis of flood impact on residential areas including assessment of flood damage is one of the important parts of flood risk management. Proper planning and implementation of preventive measures and adaptation plans require understanding the relationship between flood characteristics and damage situation; and flood damage assessment focusing in residential area is important not only to take flood preventive measures but also to help in improving living conditions of the people living in flood prone areas. This study focused on analysis of relationship between flood characteristics and extent of damage or impact on residential areas, and on development of method for flood damage assessment. This study considered Bago River basin of Myanmar as study area, which is one of the most flood prone river basins in Myanmar. To analyze flood impact on residential areas and development of method for damage assessment, data on flood characteristics and damage during recent flood events were collected through a detailed questionnaire survey. By using collected data, we analyzed the relationships between flood characteristics and damage situation in residential houses considering characteristics of building structures, construction materials, number of stories, and height of the plinth level, which were largely ignored in the previous research. Then, we developed vulnerability functions for residential building and assets for different types of houses such as permanent, semi-permanent and temporary houses to estimate the damage in economic value; and assessed flood damage to residential areas for recent largest flood events. To assess flood damage quantitatively, we presented grid-based distributed approach by integrating hydrological-hydraulic and flood loss models. The results of this study provide useful information on physical and economical flood impacts on residential areas, which could help planners, policy makers, and decision makers to establish prevention measures and policies required for flood damage reduction. The analysis of relationships between flood characteristics and damage, and method of damage assessment presented in this study enable us to quantify flood damage in monetary value more accurately that can help in better management of flood risk in the future. The damage assessment method presented in this study can also be applied in other areas.