Abstract
In Cambodia and the Vietnamese Mekong Delta, floods commonly occur during the rainy season, and a better understanding of their spatio-temporal distribution is important for both disaster prevention and the improvement of agricultural production. This study investigated spatio-temporal flood inundation and land cover change from 2002 to 2013 in the southern part of Cambodia using Terra satellite on-board Moderate Resolution Imaging Spectroradiometer (MODIS) images. The algorithm for flood inundation detection, WFFI (Wavelet-based Filter for detecting spatio-temporal changes in Flood Inundation) was used, and the parameters were modified to fit the present study. The estimated inundation areas were validated using eight Landsat images. In a comparison between the original and modified WFFIs, the modified WFFI (70–96%) exhibited better accuracy than the original WFFI (30–70%). Overall, the temporal change in the flood inundation area presented a decreasing trend, and a link to the in-situ observed water level showed a decreasing trend during the rainy season. Furthermore, the estimated flood inundation exhibited a significant delay since 2008. Based on the yearly land cover MODIS product, the permanent water body and wetland areas decreased, whereas the cropland areas increased. This was as a result of increased agricultural productivity. However, water shortage was the major obstacle to increasing agricultural productivity, and it also had a negative impact on aquatic ecology, such as fish spawning grounds.
Highlights
In Cambodia, as in the most of the countries along the Mekong River, which is the seventh longest river in Asia, floods commonly occur during the rainy season, and they have both beneficial and Environments 2019, 6, 57; doi:10.3390/environments6050057 www.mdpi.com/journal/environmentsEnvironments 2019, 6, 57 harmful effects
The original WFFI was developed in version 4 of the Moderate Resolution Imaging Spectroradiometer (MODIS) product, while version 5 was used in this study, so it was necessary to adjust the threshold value for extracting water-related pixels in WFFI
This study investigated spatio-temporal flood inundation and land cover change in the southern part of Cambodia using the Terra MODIS products
Summary
In Cambodia, as in the most of the countries along the Mekong River, which is the seventh longest river in Asia, floods commonly occur during the rainy season, and they have both beneficial and Environments 2019, 6, 57; doi:10.3390/environments6050057 www.mdpi.com/journal/environmentsEnvironments 2019, 6, 57 harmful effects. Annual flooding in the Mekong River basin provides vital resources to agro-ecosystems [2,3]. SAR images can monitor ground surface data without cloud cover effects. They are very sensitive to water surface effects due to wind and currents. Based on the optical images, several methodologies have been developed to detect surface water bodies and flood areas in different areas of research such as crop productivity estimation in paddy fields [10,11], cropping systems identification [12,13], mapping inland aquaculture [14], habitat studies for fish and aquatic life [15] and flooded disaster zones [10]
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.
