Gis-Based Flood Hazard Mapping Using Hec-Ras Model: A Case Study of Lower Mekong River, Cambodia

Abstract

Rivers are the main water sources for human and animals' lives. Unfortunately, they have been frequently damaged by flooding. Flooding has affected and threatened not only human's lives and infrastructures but also the environmental capital. This study aims to determine the application of flood frequency analysis integrated with the GIS and HEC-RAS models to prepare a multi-return period flood hazard map in the Lower Mekong River of Cambodia. A 30-year peak discharge (Kampong Cham gauging station) with a multireturn period of 10, 20, 50, and 100-years was estimated by using four distributions analysis. An EasyFit software is used to test the best distribution for the input of the HEC-RAS model to prepare the estimation of the corresponding floodplain areas. The results showed that Log-Pearson III distribution analysis of the return period of 10, 20, 50, 100 years is the best fits with the 52,208 m 3 /s, 54,990 m 3 /s, 59,381 m 3 /s, and 62,194 m 3 /s, respectively. The HEC-RAS calibration indicated a good agreement with observed data discharge 2011 and 2013. While the simulation model shows the return period of floods 10 and 20 years for the predicted depth of flooding is stable compared to the flood peaks of 2011 and 2013 discharges, but the conditions of other flood return periods are not stable. Overall, HEC-RAS with its flood hazard map is a model that can estimate the level of flood depth in the Lower Mekong River, Cambodia and is useful in providing information about the depth and characteristics of floods for river communities.

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

“…HEC-RAS is one of the popular opened source software with a Graphical User Interface (GUI) that can do hydraulic simulations and develop the flood maps for a river system of steady flow, unsteady flow, and sediment transport (Ly et al, 2018). Kim et al (2020) used HEC-RAS combined with RS for flood hazard mapping in the Lower Mekong River. The study showed that 2011 and 2013 historical floods influenced most of the flood depth considering return periods.…”

“…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…”

“…Much research on flood has been studied depend on RS. Several researchers put more attempts to support flood disaster management such as Manzul Kumar Hazarika and Bormudoi (2007), Arias et al (2012), Chung et al (2019), and Kim et al (2020). The aims of this paper are to (1) identify the spatial distribution of the 2011 flood impact, (2) evaluate how RS has been applied to flood analysis, and (3) find the gaps of RS for flood analysis over Cambodia.…”

Application of Gis in the Assessment of Flood Risk in the Region Zenica - Doboj Canton

“…Geographic Information System (GIS) mapping applications vary to flood hazard mapping, flood hazard management, hydrological data storing and management. Especially, a combination of GIS (Geographic Information System) and HEC-RAS (Hydrologic Engineering Center-River Analysis System) has a great capability in the simulation of flood hazard maps (Kim et al, 2020). Out of all-natural hazards in the world, flood is the mostcommon one.…”

Performance of UAV Image for Flood Mapping with 2 Dimensional Model in Kaliputih River, Panti District

“…In general, the advantages of HEC-RAS 2D itself are that it can simulate flooding in various flood scenarios (Ongdas et al, 2020) and estimate the level of flood depth. The results of UAV processing are used as terrain input in HEC-RAS (Mourato et al, 2017), and the discharge value is also inputted so that it can produce flood inundation modeling through simulation of the desired scenario (Kim et al, 2020). In this way, the flood modeling map produced will be much better at representing the geometry of the Kaliputih River in Kemiri Village, Panti-East Java District.…”