Mapping ecological conditions in the Okavango delta, Botswana using fine and coarse resolution systems including simulated SPOT vegetation imagery

Aspects of wetland monitoring in southern Africa are significant in the light of the Ramsar Convention, which has recently been signed by Botswana. The present work initially indicated that most ecological units in the Okavango delta can be identified and mapped using fine resolution satellite imagery and aerial photography. A second step involved assessing which of these units could also be identified using coarse resolution imagery. Contrasting results were obtained from a relatively high quality solid state sensor system (simulated SPOT 4-VEGETATION) and a relatively low quality system (NOAA-AVHRR). The extent of the water surface in the flooded areas could not be accurately mapped using NOAA-AVHRR data because of pixel saturation effects. However the presence of water was generally located using AVHRR data. The ecologically significant riparian woodlands were found to saturate pixel response on Thematic Mapper (TM) imagery. As a result of detailed comparisons, it was found that simulated SPOT VEGETATI...