干旱区生态环境知识资源中心(Arid): Analysis of the evolution of forest and preforest vegetal formations of the Sahel: case of the Wadi-Fira and Ouaddai regions in Chad

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DOI	10.4000/physio-geo.5882
	Analysis of the evolution of forest and preforest vegetal formations of the Sahel: case of the Wadi-Fira and Ouaddai regions in Chad
	Adey, Souleymane Adam; El-Abidine, Abdenbi Zine; Mustapha, Mahamat Ali; Oumar, Abdoulaye Mahamat; Ziri, Rabea; Barhadda, Najiba; Laaribya, Said; Gmira, Najib
通讯作者	Adey, SA
来源期刊	PHYSIO-GEO
ISSN	1958-573X
出版年	2018
卷号	12 页码:79-103
英文摘要	After the drought that began in the mid-1960s, rainfall in Ouaddai and Wadi-Fira regions, in eastern Chad, improved from 1990s. At the same time, the human impact on vegetal formations rose with the massive arrival of refugees and displaced persons. The effects of these factors are so far little known in this area. The present paper studies the evolution of forest and preforest formations over a period of 23 years (1987-2010). This analysis was carried out using the Landsat TM satellite images of November 4, 1987 and ETM+ of October 22, 2000 and October, 2, 2010. Five classes of land use have been discriminated against (Pure Balanites, Pure Acacias, Mixtures, Bare soil and Rock outcrop). The proportions occupied by the three first classes were respectively 0.1 %, 5.2 % and 54.3 % in 1987, 0.2 %, 2.4 % and 48.7 % in 2000 and 1.0 %, 14.3 % and 61.7 % in 2010. Between 1987 and 2000, a sharp decline was observed for Pure Acacias (-53.6 %) and Mixtures (-10.4 %). However, a significant increase was recorded from 2000 to 2010 for the same classes: +500 % for Pure Acacias and +15.5 % for Mixtures. The class of Pure Balanites never reached 1 % of the total area. In situ observations were also carried out in autumn 2016 on 240 plots. The forest flora richness is of 30 species. The average density is 53 stems.ha(-1) for Pure Balanites, 35 stems.ha(-1) for Pure Acacias and 24 stems.ha(-1) for Mixtures. Improved rainfall has favored species of lower calorific and forage values such as Calotropis procera and Leptadenia pyrotechnica. Despite the return of rainfall, the wood resources of Ouaddai and Wadi-Fira are declining because they are subject to anthropogenic pressure amplified by increase of the population.
英文关键词	Landsat image forest formation preforest formation drought evolution of vegetation Ouaddai Wadi-Fira Chad
类型	Article
语种	French
开放获取类型	DOAJ Gold
收录类别	ESCI
WOS记录号	WOS:000491268800007
WOS关键词	LAND-COVER ; CLASSIFICATION ; NIGER ; DESERTIFICATION ; DROUGHT
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/333364
作者单位	[Adey, Souleymane Adam; Ziri, Rabea; Barhadda, Najiba; Laaribya, Said; Gmira, Najib] Univ Ibn Tofail, Lab Biol Sante Environm, Unite Rech Biodivers Environm, Kenitra, Morocco; [El-Abidine, Abdenbi Zine] Ecole Natl Forestiere Ingenieurs, Dept Sol Eau Biodivers, Sale, Morocco; [Mustapha, Mahamat Ali] Univ NDjamena, Dept Geog, Ndjamena, Chad; [Oumar, Abdoulaye Mahamat] Agence Natl Grande Muraille Verte, Ndjamena, Chad
推荐引用方式 GB/T 7714	Adey, Souleymane Adam,El-Abidine, Abdenbi Zine,Mustapha, Mahamat Ali,et al. Analysis of the evolution of forest and preforest vegetal formations of the Sahel: case of the Wadi-Fira and Ouaddai regions in Chad[J],2018,12:79-103.
APA	Adey, Souleymane Adam.,El-Abidine, Abdenbi Zine.,Mustapha, Mahamat Ali.,Oumar, Abdoulaye Mahamat.,Ziri, Rabea.,...&Gmira, Najib.(2018).Analysis of the evolution of forest and preforest vegetal formations of the Sahel: case of the Wadi-Fira and Ouaddai regions in Chad.PHYSIO-GEO,12,79-103.
MLA	Adey, Souleymane Adam,et al."Analysis of the evolution of forest and preforest vegetal formations of the Sahel: case of the Wadi-Fira and Ouaddai regions in Chad".PHYSIO-GEO 12(2018):79-103.