Flood damage assessment on rice crop in the Stung Sen River Basin of Cambodia

Abstract

In Cambodia, rice production is important for the majority of rural populations as the main source of income. However, historical extreme flood events, especially the 2011 flood, caused significant damage to rice production due to insufficient flood preparedness and mitigation. To reduce the risk of damage, flood damage assessment is critical for providing essential information about potential risks to support the decision-making process and policy development in flood risk management. In this study, a physically based rainfall–runoff–inundation (RRI) model was used to simulate flood inundation in the Stung Sen River Basin of Cambodia, and then damage to rice crops was estimated based on the simulated inundation depth and duration that resulted from the RRI model. The simulated river discharges were calibrated and validated for 2011 and 2009 flood events, respectively. Indeed, the simulated flood inundation areas were compared with flood maps derived from satellite imagery to check their accuracy. As a result, it was confirmed that these results were reasonable and adequate. In the case of the 2011 flood, a distribution map of rice crop damage was created to represent the potentially affected rice areas at various levels of damage. Furthermore, the total of estimated affected rice areas was found to be close to the reported damage data, with an overlap of 89%. Overall, the preliminary results from this study are expected to be useful for key stakeholders at all levels, especially decision-makers, in planning better risk reduction strategies, for instance, when choosing the appropriate flood control option to cope with future extreme flood events.