Developing Flood Vulnerability Functions through Questionnaire Survey for Flood Risk Assessments in the Meghna Basin, Bangladesh

Abstract

Flood vulnerability is estimated by Flood Damage Functions (FDFs), which are crucial for integrated flood risk assessment for developing sustainable flood management, mitigation, and adaptation strategies under global change. However, the FDFs, either empirical or synthetic, are not available in Bangladesh. Therefore, this paper focused on developing the synthetic type of FDFs for agriculture and rural households through the data of a well–structured questionnaire survey conducted in two pilot sub–districts of northeastern Bangladesh in the Meghna River basin. Multiple regression analyses were performed on the collected data, and the best performing models were selected to establish FDFs. The FDF for agriculture (~196 samples) was developed concerning damage to Boro rice, whereas the FDFs for households (~165 samples) were developed concerning damage to the buildings and household property of three house types (Mud, Brick, and Concrete), separately. The results revealed that there were no yield losses when the water levels were lower than 25 cm (~rice tiller height), and the yield losses were ~100% when the water levels were 70–75 cm deep (~rice grain height). Mud houses and their household property were found the most flood–vulnerable and likely to experience total damage when the water levels exceeded 150 cm above the plinth level, whereas the damage to Brick and Concrete houses and their household property was found likely to remain partial even when the water levels exceeded 150 cm above the plinth level. The developed FDFs can be used to assess potential flood risk in the study area for sustainable and effective management of flood disasters and build back better under global change in the future.

Impact of Canal Encroachment on Flood and Economic Vulnerability in Northern Bangladesh

“…Rapid population growth, agriculture, human settlement, cash cropping, shifting cultivation, and unplanned infrastructure development were identified as the primary causes of encroachment in the study, which is consistent with previous research [51,[54][55][56]. As a result, when a large amount of water flows in the canals and rivers in Bangladesh during the monsoon, it causes flooding and has serious consequences for the livelihood and economy of the affected people as well as the country [28,57,58]. Moreover, researchers have identified the primary reason for waterlogging in the major cities in Bangladesh as the shrinkage of natural drains due to encroachment [59].…”

“…ACI considers the methods for selecting, standardizing, and weighting indicators of events, and is as important as the characteristics of indicators have spatial variability [27]. Although many studies have been conducted to assess the flood vulnerability of rivers [28][29][30] and reservoirs, there is a lack of research using FVI to investigate flood vulnerability due to canal encroachment. Moreover, the integration of FVI and ACI has been less studied in flood vulnerability assessment.…”

Economic Loss due to the Failure of a Cascade Dam: A Study Case in the Saguling-Cirata-Jatiluhur Dam

“…The depth-damage function is usually derived through two methods. One is based on the damage data of past floods, and the other is from a hypothetical analysis based on land cover patterns, types of objects, information from a questionnaire survey, etc., known as synthetic stage-damage functions [30].…”

A new framework for flood damage assessment considering the within-event time evolution of hazard, exposure, and vulnerability

“…Among crops, we choose rice as its damaging is perhaps the most well documented (e.g., Khairul et al, 2022;Nguyen et al, 2021;Samantaray et al, 2015;Singh et al, 2011;Zhang et al, 2015). In particular, we use the data and damage functions for rice at maturity stage, as given by Shrestha et al (2016).…”