Evaluation of the runoff potential in high relief semi-arid regions using remote sensing data: application to Bolivia

Abstract

The objective of this study is to develop a methodology based on the combined use of optical and radar images for evaluating the runoff potential in high relief, semi-arid environments. We present a method based on the use of multisource satellite images (RADARSAT-1 SAR, Landsat-7 ETM⁺ and SPOT-4 HRV) for determining land use and the vegetation cover ratio in order to evaluate the runoff potential in Bolivia. Various band combinations provide classification rates greater than 80% for the mapping of land use. Basically, in over 83% of the watershed, the runoff potential is greater than 0.5 on a scale from 0 to 1.

Résumé.La contribution fondamentale de l'étude est le développement d'une méthodologie permettant l'utilisation conjointe d'images optique et radar dans l'évaluation du potentiel de ruissellement en milieu semi-aride de forte énergie de relief. Nous avons conçu une méthode d'exploitation d'images satellitaires multisources (RSO de RADARSAT-1, ETM⁺ de Landsat-7 et HRV de SPOT-4) afin d'évaluer le potentiel de ruissellement en Bolivie. Plusieurs combinaisons de bandes donnent des taux de classification supérieurs à 80% pour la cartographie de l'occupation du sol. Sur 83% du bassin, le potentiel de ruissellement est supérieur à 0.5 sur un maximum de 1.

Acknowledgments

We thank the government of the Ivory Coast, the AUCC (Association of Universities and Colleges of Canada) as well as NSERC (project 4250) for their financial and material support.