干旱区生态环境知识资源中心

The Yaere flood plain in north Cameroon is subject to annual flooding caused by local rainfall and Logone River overflow. Lame evaporative loss (12 km(3) year(-1) from this 8000 km(2)-flooded area causes a significant loss in water supply to Lake Chad. Flood monitoring is performed using the 10-daily 1 km spatial resolution small water body (SWB) product generated by the Joint Research Centre (JRC) of the European Commission, as a result of processing SPOT VEGETATION images. As this method was initially designed for the detection of small water bodies in arid and semi-arid regions. a field validation showed the benefits and drawbacks for the monitoring of large flood plains. Difficulties in reconstructing the surfaces of lame open water bodies were observed, while a good ability for reproducing water spreading and irrigation conditions over the rice-growing areas was proven. Observed water levels at the outlet of the plain were fully consistent with remotely monitored flood spreading across the whole plain that occurs when the maximum discharge of the Logone River is greater than 1500 m(3) s(-1). Annual SWB composite maps coupled with DEM information were found to provide consistent information on the water path across the plain.