Caractérisation morphologique des cuvettes oasiennes du Centre-Est du Niger
Located in semi-arid to arid areas of Niger, the oasis basins of the Department of Gouré are currently threatened with silting due to the degradation of vegetation cover and the increased efficiency of erosive winds. To understand the silting up process around these basins, characterization of their...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Physio-Géo
2017-12-01
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| Series: | Physio-Géo |
| Subjects: | |
| Online Access: | https://journals.openedition.org/physio-geo/5607 |
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| Summary: | Located in semi-arid to arid areas of Niger, the oasis basins of the Department of Gouré are currently threatened with silting due to the degradation of vegetation cover and the increased efficiency of erosive winds. To understand the silting up process around these basins, characterization of their shapes and orientations was undertaken. The compactness coefficient of GRAVELIUS helped highlight circular basins (8,5 %), ovoid (46,8 %), amoeboid (10,9 %), stretched (17,6 %) and very stretched with amoeboid tendency (16,1 %). Circular or ovoid shape of oasis basins refer to the drains that are partially filled with wind. The stretched and very stretched shapes are linked to the hydrographic network fragmentation by dunes edifices. Finally, the measurement of the orientation allowed to assess the distribution between four major sectors: E-W (22,8 %), N-S (21,4 %) NE-SW (21,6 %) and SE-NW (34,3 %). The oasis basins oriented E-W and NE-SW are associated with longitudinal dunes and oriented N-S and SE-NW with transverse dunes. |
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| ISSN: | 1958-573X |