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Détection des nuages de poussières sur les images satellitaires Météosat et leur utilisation comme traceur pour l'identification des zones de déflation des sols par érosion éolienne
| Content Provider | Semantic Scholar |
|---|---|
| Author | Bayoko, Abdoulaye Konaté, Souleymane Traore, Farid Fongang, Siméon |
| Copyright Year | 1996 |
| Abstract | Many studies have been already done on the identification of dusts clouds on the Meteosat satellite images (FRASER, 1976; GRIGGS, 1978; M. LEGRAND, 1990 ). Most of these worlcs are based on the principle of the construction of a reference image corresponding to a clear weather situation and the arithmetical subtraction of numerical accounts of this image from the numerical accounts of the images to be studied and which contain the structure we want to detect. This method is insufficient when the numerical accounts of the image to be treated are smaller than the numerical accounts of the reference image (for example in the case of night images or during a temperature inversion) if any other precmtion i s not taken during the treatment. In fact, in this article we have presented a method based on the applying of the logical a EXCLUSIVE OR s between a reference image and an image to be treated. This method enables to draw out between two images A and B, the whole structures which belong to A or to B without simultaneously belong to A and B. Applied to a reference image and to the image to be treated, the method has enabled us to detect an expansion of dusts clouds over the Sahelian zone during a temperature inversion. The source of this dusts expulsion should be located in the Chad Lake area. Satellite imagery has enabled us to define the East West and North South spreadings of dusts cloud. Associating the ground measures of particles concentrations effected by means of a cascades impactor and the Sodar echo (for the determination of the temperature inversion height), we have estimated at 5,45 millions of tons the dusts quantity emitted from the ground during this dust episode. So, we have quantified the land vulnerability in this locality to the aeolian erosion deflation. |
| Starting Page | 557 |
| Ending Page | 566 |
| Page Count | 10 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_6/colloques2/010008434.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
