The Sahara

A desert of change

Research output: Chapter in Book/Report/Conference proceedingChapter

1 Citation (Scopus)

Abstract

The Sahara Desert has a changing surface area depending on the rainfall occurring on the Sahel region south of this desert. Climatic parameters (precipitation and temperature) were obtained for many meteorological stations distributed within the Sahara and Sahel countries. The bulk of the Sahara Desert is dry and hot. Wind direction was extracted from the orientation of sand dunes of major sand seas as inferred from 30 Landsat satellite images (60 m spatial resolution). Sand dunes mostly belong to the longitudinal type and follow a southeast direction at the eastern Sahara and a southwestern trend at the majority of the desert. Topographic variations were analyzed using digital elevation models (1 km spatial resolution) revealing that the Sahara is generally a plateau desert except for some mountainous spots occurring at its northwest and middle parts. The surface area change of this desert was estimated using the Normalized Difference Vegetation Index (NDVI) product from 480 satellite images acquired from the Advanced Very High Resolution Radiometer (AVHRR) (8 km spatial resolution) and covering the entire Africa between 1984 and 2003. Image processing applied included a robust unsupervised classification scheme. Results showed that the Sahara Desert witnessed two opposite episodes of expansion and contraction. The period 1984-1993 was a cycle of expansion and the period 1994-2003 was a cycle of contraction. Maximum desert area was observed during 1984 (10.35 million km2) and minimum area was during 1999 (9.15 million km2). The average area of the Sahara Desert between 1984 and 2003 was 9.87 million km2.

Original languageEnglish
Title of host publicationSand Dunes
Subtitle of host publicationEcology, Geology and Conservation
PublisherNova Science Publishers, Inc.
Pages101-114
Number of pages14
ISBN (Print)9781611227390
Publication statusPublished - 2011

Fingerprint

desert
spatial resolution
contraction
dune
surface area
unsupervised classification
AVHRR
image processing
NDVI
wind direction
Landsat
digital elevation model
plateau
rainfall
sand
temperature

ASJC Scopus subject areas

  • Environmental Science(all)

Cite this

Hereher, M. E. (2011). The Sahara: A desert of change. In Sand Dunes: Ecology, Geology and Conservation (pp. 101-114). Nova Science Publishers, Inc..

The Sahara : A desert of change. / Hereher, Mohamed E.

Sand Dunes: Ecology, Geology and Conservation. Nova Science Publishers, Inc., 2011. p. 101-114.

Research output: Chapter in Book/Report/Conference proceedingChapter

Hereher, ME 2011, The Sahara: A desert of change. in Sand Dunes: Ecology, Geology and Conservation. Nova Science Publishers, Inc., pp. 101-114.
Hereher ME. The Sahara: A desert of change. In Sand Dunes: Ecology, Geology and Conservation. Nova Science Publishers, Inc. 2011. p. 101-114
Hereher, Mohamed E. / The Sahara : A desert of change. Sand Dunes: Ecology, Geology and Conservation. Nova Science Publishers, Inc., 2011. pp. 101-114
@inbook{c07cd6b742794757868b6c26565bbd64,
title = "The Sahara: A desert of change",
abstract = "The Sahara Desert has a changing surface area depending on the rainfall occurring on the Sahel region south of this desert. Climatic parameters (precipitation and temperature) were obtained for many meteorological stations distributed within the Sahara and Sahel countries. The bulk of the Sahara Desert is dry and hot. Wind direction was extracted from the orientation of sand dunes of major sand seas as inferred from 30 Landsat satellite images (60 m spatial resolution). Sand dunes mostly belong to the longitudinal type and follow a southeast direction at the eastern Sahara and a southwestern trend at the majority of the desert. Topographic variations were analyzed using digital elevation models (1 km spatial resolution) revealing that the Sahara is generally a plateau desert except for some mountainous spots occurring at its northwest and middle parts. The surface area change of this desert was estimated using the Normalized Difference Vegetation Index (NDVI) product from 480 satellite images acquired from the Advanced Very High Resolution Radiometer (AVHRR) (8 km spatial resolution) and covering the entire Africa between 1984 and 2003. Image processing applied included a robust unsupervised classification scheme. Results showed that the Sahara Desert witnessed two opposite episodes of expansion and contraction. The period 1984-1993 was a cycle of expansion and the period 1994-2003 was a cycle of contraction. Maximum desert area was observed during 1984 (10.35 million km2) and minimum area was during 1999 (9.15 million km2). The average area of the Sahara Desert between 1984 and 2003 was 9.87 million km2.",
author = "Hereher, {Mohamed E.}",
year = "2011",
language = "English",
isbn = "9781611227390",
pages = "101--114",
booktitle = "Sand Dunes",
publisher = "Nova Science Publishers, Inc.",

}

TY - CHAP

T1 - The Sahara

T2 - A desert of change

AU - Hereher, Mohamed E.

PY - 2011

Y1 - 2011

N2 - The Sahara Desert has a changing surface area depending on the rainfall occurring on the Sahel region south of this desert. Climatic parameters (precipitation and temperature) were obtained for many meteorological stations distributed within the Sahara and Sahel countries. The bulk of the Sahara Desert is dry and hot. Wind direction was extracted from the orientation of sand dunes of major sand seas as inferred from 30 Landsat satellite images (60 m spatial resolution). Sand dunes mostly belong to the longitudinal type and follow a southeast direction at the eastern Sahara and a southwestern trend at the majority of the desert. Topographic variations were analyzed using digital elevation models (1 km spatial resolution) revealing that the Sahara is generally a plateau desert except for some mountainous spots occurring at its northwest and middle parts. The surface area change of this desert was estimated using the Normalized Difference Vegetation Index (NDVI) product from 480 satellite images acquired from the Advanced Very High Resolution Radiometer (AVHRR) (8 km spatial resolution) and covering the entire Africa between 1984 and 2003. Image processing applied included a robust unsupervised classification scheme. Results showed that the Sahara Desert witnessed two opposite episodes of expansion and contraction. The period 1984-1993 was a cycle of expansion and the period 1994-2003 was a cycle of contraction. Maximum desert area was observed during 1984 (10.35 million km2) and minimum area was during 1999 (9.15 million km2). The average area of the Sahara Desert between 1984 and 2003 was 9.87 million km2.

AB - The Sahara Desert has a changing surface area depending on the rainfall occurring on the Sahel region south of this desert. Climatic parameters (precipitation and temperature) were obtained for many meteorological stations distributed within the Sahara and Sahel countries. The bulk of the Sahara Desert is dry and hot. Wind direction was extracted from the orientation of sand dunes of major sand seas as inferred from 30 Landsat satellite images (60 m spatial resolution). Sand dunes mostly belong to the longitudinal type and follow a southeast direction at the eastern Sahara and a southwestern trend at the majority of the desert. Topographic variations were analyzed using digital elevation models (1 km spatial resolution) revealing that the Sahara is generally a plateau desert except for some mountainous spots occurring at its northwest and middle parts. The surface area change of this desert was estimated using the Normalized Difference Vegetation Index (NDVI) product from 480 satellite images acquired from the Advanced Very High Resolution Radiometer (AVHRR) (8 km spatial resolution) and covering the entire Africa between 1984 and 2003. Image processing applied included a robust unsupervised classification scheme. Results showed that the Sahara Desert witnessed two opposite episodes of expansion and contraction. The period 1984-1993 was a cycle of expansion and the period 1994-2003 was a cycle of contraction. Maximum desert area was observed during 1984 (10.35 million km2) and minimum area was during 1999 (9.15 million km2). The average area of the Sahara Desert between 1984 and 2003 was 9.87 million km2.

UR - http://www.scopus.com/inward/record.url?scp=84892014818&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84892014818&partnerID=8YFLogxK

M3 - Chapter

SN - 9781611227390

SP - 101

EP - 114

BT - Sand Dunes

PB - Nova Science Publishers, Inc.

ER -