Comprehensive Assessment of Flood Hazard, Vulnerability, and Flood Risk at the Household Level in a Municipality Area: A Case Study of Nan Province, Thailand

Thanasit Promping,Tawatchai Tingsanchali

doi:10.3390/w14020161

Abstract

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 ground elevation is low, population density is high, and the number of household properties are high. In conclusion, this new comprehensive methodology yielded realistic results and can be used further to assess the effectiveness of various proposed flood mitigation measures.

Highlights

Academic Editors: Chris Bradley and Floods are the most frequent type of disasters
The results of the model’s calibration at stations N64 and N1 were found to be satisfactory with coefficients of determination of 0.72 and 0.76; Nash–Sutcliffe efficiencies of 0.67 and 0.64; percent biases of 15.78 and 15.11; volume ratios of 0.95 and 0.89; normalized root mean square errors of
The HEC-HMS hydrological model and the HEC-RAS flood flow simulation model were applied to predict flood depths, velocities, and durations for the return periods of 10, 50, 100, and 500 years; The model computed results showed that significant flood hazards occur in PhuminThali and Phuang-Payom villages in the southern part of the municipal area and in Mueang Len village in the northeastern part of the area

Summary

Introduction

Academic Editors: Chris Bradley and Floods are the most frequent type of disasters. They can cause widespread devastation, loss of life, and damage to personal property and public infrastructure. 2017, floods affected more than 2 billion people, or 29% of the world population [1]. Floods cause more than USD 40 billion in damage worldwide annually [2].

Objectives

Methods

Results

Conclusion