Multi-Variate Analyses of Flood Loss in Can Tho City, Mekong Delta (original) (raw)
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Flood Loss Models and Risk Analysis for Private Households in Can Tho City, Vietnam
Water, 2017
Vietnam has a long history and experience with floods. Flood risk is expected to increase further due to climatic, land use and other global changes. Can Tho City, the cultural and economic center of the Mekong delta in Vietnam, is at high risk of flooding. To improve flood risk analyses for Vietnam, this study presents novel multi-variable flood loss models for residential buildings and contents and demonstrates their application in a flood risk assessment for the inner city of Can Tho. Cross-validation reveals that decision tree based loss models using the three input variables water depth, flood duration and floor space of building are more appropriate for estimating building and contents loss in comparison with depth-damage functions. The flood risk assessment reveals a median expected annual flood damage to private households of US$3340 thousand for the inner city of Can Tho. This is approximately 2.5% of the total annual income of households in the study area. For damage reduction improved flood risk management is required for the Mekong Delta, based on reliable damage and risk analyses.
Geomatics, Natural Hazards and Risk
The continuous increase in damages to flood disasters globally has informed the need to assess vulnerability of built-up exposures for future flood risk reduction. The aim of this paper is to understand the contributions of some important variables in flood damage processes and develop loss functions for global building types, for the estimation of flood economic damages in Chao Phraya river basin, Thailand. We obtained empirical damage data (118 samples) through questionnaire survey in the study area for analysis. Using multiple linear regressions analysis, we generated loss functions for the aggregated residential building incorporating multiple damage factors. Further, disaggregated vulnerability curves (as a function of water depth) were established using logarithm function for three global building types in the study area. Results showed that, under flood condition in the study area, water depths and building age are very important damage factors, other variables are also emphasized. The loss models show maximum predicted vulnerability indices of 0.36, 0.30 and 0.10 for wooden, concrete frame and unreinforced masonry, and reinforced concrete moment frame, respectively. These functions can be used for modeling flood damage, for future disaster risk reduction and for risk comparison across countries.
IOP Conference Series: Earth and Environmental Science, 2019
Singkawang City is in the Province of West Kalimantan, which is located above an alluvial plain, that causing the city to be prone of flood. The last flood that occurred happened in 2016, which resulted in many flooded buildings and hundreds evacuated resident. This research purposes are to identify the hazard level of flooding and then proceed with the assessment of economic losses. The flood hazard levels are obtained by overlaying the flood characteristics parameters, i.e. frequency, duration, and height of the flood. The method for assessing the rate of the damage is done by purposive random sampling method with consider to the flood hazard level and building value. The result showed that from 84,96 ha of flooded areas, flood hazard level is dominated by low and medium hazard, with percentage of area 44,02% and 43,03%, and high classification with percentage of 12,95%. The loss assessment for this research shows that the total loss from the flood is Rp15.838.232.500 (1.150 milli...
Flood risk assessment for delta mega-cities: a case study of Jakarta
Natural Hazards, 2014
Jakarta has suffered major floods in 2002, 2007, and 2013. To cope with and adapt to both the current and future flood problem, the city requires quantitative assessments of flood risk. In this study, we develop a flood risk assessment model for Jakarta. The model is based on the Damagescanner model, adapted for Jakarta using local information on hazard, exposure, and vulnerability. The model was first set up using existing estimates of economic exposure of different land use classes to represent exposure and depth-damage functions (vulnerability curves) from several existing studies in southeast Asia to represent vulnerability. Using these data to simulate damage led to an overestimation by several orders of magnitude. Hence, we held a series of expert meetings and workshops with local stakeholders to develop specific estimates of economic exposure per land use class and to derive vulnerability curves specific for Jakarta. We compare the resulting simulated damages to reported damages and found them to be in good agreement, giving confidence in the use of the model for flood risk assessment. Under current conditions, we found the annual expected damage due to river flooding in Jakarta to be approximately USD 321 million per year. We also examined the sensitivity of flood risk assessments to the use of different vulnerability curves. The sensitivity is high: using the six curves described in this study to simulate risk led to a factor eight difference between Electronic supplementary material The online version of this article (
2015
Increasing population has resulted in an increase in the number of property ownerships. Therefore, a greater percentage of the country’s land area, often in areas that previously have been not fit for urban development and human settlement, have been taken up to cater for the need for accommodation (Eves, 2014). These increased numbers of properties, changes in water collection, flows and poor drainage system coupled with heavy monsoon rainfall, intense convection rainstorms and other local factors have caused seasonal floods in Malaysia (Chan, 1996; Eves, 2014). According to the Malaysian National Security Council [MNSC] (2015), flood is the most common type of disaster that occurs in Malaysia. Floods occur annually in Malaysia, causing damage to property and loss of life. The worst flood event in Malaysia was in December 2014 that rendered people helpless. The moving water had destructive powers that picked up and carried off bridges, houses, trees, and cars. The east coasts state...
Framework of Spatial Flood Risk Assessment for a Case Study in Quang Binh Province, Vietnam
Sustainability
Vietnam has been extensively affected by floods, suffering heavy losses in human life and property. While the Vietnamese government has focused on structural measures of flood defence such as levees and early warning systems, the country still lacks flood risk assessment methodologies and frameworks at local and national levels. In response to this gap, this study developed a flood risk assessment framework that uses historical flood mark data and a high-resolution digital elevation model to create an inundation map, then combined this map with exposure and vulnerability data to develop a holistic flood risk assessment map. The case study is the October 2010 flood event in Quang Binh province, which caused 74 deaths, 210 injuries, 188,628 flooded properties, 9019 ha of submerged and damaged agricultural land, and widespread damages to canals, levees, and roads. The final flood risk map showed a total inundation area of 64,348 ha, in which 8.3% area of low risk, 16.3% area of medium ...
Environment Systems and Decisions, 2018
The use of different approaches in the development of flood damage models in various countries is expected to affect flood damage modelling at a regional or global scale. Since these models are often used as tools for disaster management and decision making, it is very needful to understand the comparative similarity and differences in countries' loss models; this can help in the overall integration for developing regional risk models and crosscountry risk assessment. In this study, empirically generated generalised loss models in three Asian countries (Sri Lanka, Thailand and Japan) were compared and applied to estimate potential flood damages in two different urban river basins. For each case study, each model was normalised using cost prices and floor areas (as applied to each country) and were integrated within the Geographic Information Systems (GIS) to estimate damages for the flood events. Using the mean vulnerability index of corresponding building types for the selected countries, a single model for regional flood risk assessment was created. However, the study showed that there are variations in the vulnerability and the potential flood damage estimates of similar global building types from the three countries, despite being developed by the same approach. These are attributed to the country's specific conditions such as building regulations and codes, GDP per capita, cost price of building materials. Our results suggest that the average vulnerability index from the countries however reduced potential errors in the estimates. Moreover, it is proposed that the average regional vulnerability model derived with empirical data inputs from all the countries for regional risk assessment and crosscountry comparison. Therefore, it can predict near accurate potential flood damages, which can serve as measures for regional flood disaster risk management plans.
Water, 2022
Estimating flood hazard, vulnerability, and flood risk at the household level in the past did not fully consider all relevant parameters. The main objective of this study is to improve this drawback by developing a new comprehensive and systematic methodology considering all relevant parameters and their weighting factors. This new methodology is applied to a case study of flood inundation in a municipal area of Nan City in the Upper Nan River Basin in Thailand. Field and questionnaire surveys were carried out to collect pertinent data for input into the new methodology for estimating flood hazard, vulnerability, and risk. Designed floods for various return periods were predicted using flood simulation models for assessing flood risk. The flood risk maps constructed for the return periods of 10–500 years show a substantial increase in flood risk with the return periods. The results are consistent with past flood damages, which were significant near and along the riverbanks where gro...
Journal of Environmental Science and Engineering B, 2018
Urban flooding has impacted significantly on people's living: economic development, environmental pollution, etc.. It has been the serious problem of many cities in the world, especially in urban areas in developing countries because urbanization is too fast but lack of adaptive management planning and infrastructure. In Vietnam, the big cities, such as HCM (Ho Chi Minh) City, Hanoi, etc. have also been influenced severely by floods. By early 2017, HCM City has 171 flooded sites assigned by the district level; 40 submergence points assigned by Steering Center of Flooding Control Program, and 9 tidal flooded points. The paper will establish a suitable method for assessing flood vulnerability in HCM City from natural, social and environmental aspects. The results of a case study in District 6 show that there are four wards with high vulnerability and 10 wards with average vulnerability.
Household Economic Losses of Urban Flooding: Case Study of Can Tho City, Vietnam
2018
This article examines the economic losses caused by urban flooding in Can Tho City, Vietnam. Opportunity-cost and household co.0sts are emphasized. Household interviews showed that annual economic losses due to flooding were 11 % of household annual income. Furthermore, the study reveals that there are differences in cost structure at different stages of flooding. An estimated regression model suggests that household location and education status were significant factors affecting economic losses. The empirical results further indicated that the before flooding cost used as proxy measure for prevention activities significantly reduced the economic cost of urban flooding in Can Tho City.