Application of multitemporal ERS-2 synthetic aperture radar in delineating rice cropping systems in the Mekong River Delta, Vietnam

The authors report the use of multitemporal ERS-2 satellite synthetic aperture radar (SAR) images in delineating and mapping areas under different rice cropping systems in the Mekong River Delta, Vietnam. Change index maps were generated from seven images acquired between May and December 1996. Using a 3-dB threshold, the pixels in each change index (CI) map were classified into one of three classes: Increasing, decreasing, or constant backscattering. Five of the CI maps were used to generate a composite map with 243 possible change classes. These change classes were grouped into thematic categories of rice cropping systems using two methods: human visual inspection and a semiautomatic hierarchical clustering algorithm. The derived thematic maps were compared with SPOT scenes acquired during the same rice seasons.