ETUDE DES CORRELATIONS ENTRE LA MORPHOLOGIE DES BRANCHES AMONT DU RESEAU HYDROGRAPHIQUE ET LE DEGRE DE MISE EN CULTURE EN HAUTE GUINEE - EXAMEN DE L'IMAGERIE
The work presented here is part of a research project, called "Joliba". Dealing with the definition of remote sensing techniques potentialities for crop production forecasting in West Africa. In this project, promoted by the European Communities, the Joint Research Centre (JRC) of Ispra is responsible for the scientific and technical aspects, in collaboration with national and regional authorities in West Africa such as the "Comite" Inter etats de Lutte Contre la Secheresse au Sahel" (C.I.L.S.S. - Ouagadougou - Burkina). Success of crop production forecasting is conditioned by the mapping of actual cultivated lands on one hand, and the definition of yield classes for specific crops on the other hand. This study concerns the first aspect. Mapping of cultivated lands over very large areas in West Africa could not be achieved using only very high resolution imagery such as the one of Landsat-IM or SPOT. The amount of data to be managed would be obviously too high. In a methodological approach, one needs to define on regional scale areas of special interest in order to minimize data treatment and interpretation. To do so, we propose the use of medium scale imagery, such as the one of Landsat-MSS, to map cultivation intensity by the means of the hydrographic network morphology. In fact agricultural activities seem to have strong consequences on the status of the hydrographic network in Tropical parts of West Africa. A preliminary study has been carried out on a test-site in Guinea. Infra-red aerial photographs and field studies have been used to put in evidence the correlation existing between cultivation intensity and hydrographic network morphology. Landsat-MSS imagery allowed to define several classes of river basins, according to their aspect on the images. An example of derived cultivation intensity is presented for one river basin. Such methodology has now to be tested on larger area of West Africa where facts about cultivation intensity could be obtained.
Bibliographic Reference: REVUE DE GEOMORPHOLOGIE DYNAMIQUE, VOL. XXXV (1986), NO. 2, PP. 49-61
Record Number: 1989126042901 / Last updated on: 1989-01-01
Available languages: fr