Flood Hazard Mapping and Assessment on the Angkor World Heritage Site, Cambodia

Abstract

World Heritage sites in general are exposed to the impacts of natural hazards, which threaten their integrity and may compromise their value. Floods are a severe threat to the Angkor World Heritage site. Studies of regional floods and flood hazard zoning have played an increasingly important role in ensuring sustainability of the Angkor site. This study developed a flood hazard index (FHI) model based on a geographic information system (GIS) and used synthetic aperture radar (SAR) data to extract historical floods at Angkor from 2007 to 2013. Four indices (flood affected frequency, absolute elevation, elevation standard deviation, drainage density) were used to identify flood-prone areas. The Analytic Hierarchy Process (AHP) and the Delphi method were employed to determine the weight of each index. The weighted indices were then used to develop a distribution map of flood hazards at Angkor. The results show that 9 monuments are at risk by potential floods among the 52 components of the Angkor monuments. The high hazard and moderate-to-high hazard areas in the core zone are mainly located surrounding the West Baray but will not bring direct risk impact on the monuments located in the core archaeological zone. The moderate hazard areas are located on both sides of the Siem Reap and Roluos rivers and in the flooded area of the Tonle Sap Lake in the core archaeological zone. These areas cover 19.4 km2, accounting for 9.13% of the total area of the core zone. This moderate hazard zone poses a greater flood threat to the core zone and must be given higher attention. The buffer zone is a small area with fewer sites. As such, flooding has a low impact on the buffer zone. The methods used in this study can be applied to flood hazard assessments of other heritage sites in Southeast Asia.

Flood Susceptibility Mapping Using GIS-Based Analytic Network Process: A Case Study of Perlis, Malaysia

“…Other studies have used support vector machine models [28], ANN model [29], ANFIS [30], a combination of fuzzy logic and support vector machine [31], integrated machine learning and statistical models [32], DT algorithm [33], logistic regression [34], and an ensemble of regression trees and support vector machine [35]. Despite the recent focus on quantitative methods of flood vulnerability analysis, qualitative approaches such as the AHP and ANP are still being adopted [36,37] due to their relative simplicity in computing flood influencing parameters. The weights of each of the parameter considered in an AHP model are determined by expert opinions unlike the quantitative methods that require rigorous training and computations [28].…”

Using AHP and Spatial Analysis to Determine Water Surface Storage Suitability in Cambodia

“…Deciding where to construct infrastructure is a complicated process that requires managers to evaluate a multitude of technical criteria, such as hydrologic geospatial data. To avoid reliability issues, infrastructure managers need to incorporate multiple experts (e.g., civil engineers, hydrologists, urban planners) to truly develop a more accurate decision-model However, in countries with limited technical capacity, there has been limited work evaluating methods to synthesize this knowledge [4,58,59]. We theorized that the AHP theory could fill this knowledge gap to improve decision-making processes involving multiple technical criteria and expert opinions.…”

Flood Disaster Studies: A Review of Remote Sensing Perspective in Cambodia

“…The flood hazard mapping obtained by using SAR images from different years and flood hazard index (FHI) was developed to analyze the flood in the Angkor area. The area around Angkor Wat monuments must be monitored, and flood control measures should be taken into account to protect the site from flooding (Liu et al, 2019). MODIS and DEM were used to investigate the seasonal change of inundation areas and water volume and floodplain of Tonle Sap (Siev et al, 2016).…”

“…S-Band Doppler weather radar meteor 650C, which has a range of 450 km located in Phnom Penh was not used in any flood analysis over Cambodia. (Hazarika et al, 2007;Kim et al, 2020;Liu et al, 2019;Ly et al, 2018;Son et al, 2019;Try et al, 2019) Flood (Kim et al, 2019;Mohammed et al, 2018;Sakamoto et al, 2007;Siev et al, 2016;Tangdamrongsub et al, 2016;Vichet et al, 2019;Yu et al, 2019) Flood damage assessment DEM * Landsat-8 * UNOSAT * RRI (Chung et al, 2019) * is number of studies have been used…”