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: Mahamadou Karimou Barké, Issa Oussein, Charles Bielders, Karimou J.M. Ambouta, Bernard Tychon
Format: Article
Language:English
Published: Physio-Géo 2017-12-01
Series:Physio-Géo
Subjects:
Online Access:https://journals.openedition.org/physio-geo/5607
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author Mahamadou Karimou Barké
Issa Oussein
Charles Bielders
Karimou J.M. Ambouta
Bernard Tychon
author_facet Mahamadou Karimou Barké
Issa Oussein
Charles Bielders
Karimou J.M. Ambouta
Bernard Tychon
author_sort Mahamadou Karimou Barké
collection DOAJ
description 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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publisher Physio-Géo
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series Physio-Géo
spelling doaj-art-5143ae2a4f8f4e828e117b0d509c42e62025-08-20T02:34:24ZengPhysio-GéoPhysio-Géo1958-573X2017-12-011125527610.4000/physio-geo.5607Caractérisation morphologique des cuvettes oasiennes du Centre-Est du NigerMahamadou Karimou BarkéIssa OusseinCharles BieldersKarimou J.M. AmboutaBernard TychonLocated 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.https://journals.openedition.org/physio-geo/5607oasian basinsshape indexGraveliusorientationGouréNiger
spellingShingle Mahamadou Karimou Barké
Issa Oussein
Charles Bielders
Karimou J.M. Ambouta
Bernard Tychon
Caractérisation morphologique des cuvettes oasiennes du Centre-Est du Niger
Physio-Géo
oasian basins
shape index
Gravelius
orientation
Gouré
Niger
title Caractérisation morphologique des cuvettes oasiennes du Centre-Est du Niger
title_full Caractérisation morphologique des cuvettes oasiennes du Centre-Est du Niger
title_fullStr Caractérisation morphologique des cuvettes oasiennes du Centre-Est du Niger
title_full_unstemmed Caractérisation morphologique des cuvettes oasiennes du Centre-Est du Niger
title_short Caractérisation morphologique des cuvettes oasiennes du Centre-Est du Niger
title_sort caracterisation morphologique des cuvettes oasiennes du centre est du niger
topic oasian basins
shape index
Gravelius
orientation
Gouré
Niger
url https://journals.openedition.org/physio-geo/5607
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AT charlesbielders caracterisationmorphologiquedescuvettesoasiennesducentreestduniger
AT karimoujmambouta caracterisationmorphologiquedescuvettesoasiennesducentreestduniger
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