Abstract
Cambodia is one of the most flood-prone countries in Southeast Asia. It is geographically situated in the downstream region of the Mekong River with a lowland floodplain in the middle, surrounded by plateaus and high mountains. It usually experiences devastating floods induced by an overwhelming concentration of rainfall water over the Tonle Sap Lake’s and Mekong River’s banks during monsoon seasons. Flood damage assessment in the rice ecosystem plays an important role in this region as local residents rely heavily on agricultural production. This study introduced an object-based approach to flood mapping and affected rice field estimation in central Cambodia. In this approach, image segmentation processing was conducted with optimal scale parameter estimation based on the variation of objects’ local variances. The inundated area was identified by using Landsat 8 images with an overall accuracy of higher than 95% compared to those derived from finer spatial resolution images. Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation index products were utilized to identify the paddy rice field based on seasonal inter-variation between vegetation and water index during the transplanting stage. The rice classification result was well correlated with the statistical data at a commune level (R2 = 0.675). The flood mapping and affected rice estimation results are useful to provide local governments with valuable information for flooding mitigation and post-flooding compensation and restoration.
Highlights
The Mekong River is one of the 10 largest rivers in the world
This is the optimal segmentation result of the image, and if the scale parameter increases, it will lead to under-segmentation and misclassification of the paddy rice field
This study introduced an object-based approach for the flood mapping and affected rice field estimation using the Landsat 8 OLI and Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation index products
Summary
The Mekong River is one of the 10 largest rivers in the world. It originates in the eastern watershed of the Tibetan Plateau and extends to the Mekong Delta. The river has formed a vast hydrological system with diverse ecosystems and multicultural communities along its basin. Under the effects of the tropical climate, there are many typhoons occurring in rainy seasons, resulting in a variety of long-lasting flood events along the Mekong river basin in history. The downside of flood disasters is that it resulted in serious negative effects on the psychology of local residents, food security, the environment, and the regional economy [2,3,4,5,6,7,8]. According to the pros and cons of flooding, the goal and challenge of flood management and risk mitigation works are to reduce the negative impacts of flooding, but preserve its benefits
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
