Bibliothèque

Remote sensing

A tool to monitor and assess desertification

Dossier du CSFD N° 2  • Publié en septembre 2005 •  English

Auteur(s) : Begni Gérard, Escadafal Richard, Fontannaz Delphine, Hong-Nga Nguyen Anne-Thérèse

Remote sensing is a technique that enables to observe the radiation scattered or emitted by the Earth surface. Satellite-based remote sensing allows regular, repetitive, accurate observations of nearly the whole planet, at various spatial and temporal scales, in several wavelength fields.

Such observations render the nature, state, temporal and spatial variations of the properties of the objects at the Earth surface. By way of example, water-covered areas, roughness, soil moisture, changes in the nature of land, density and phenological evolution of the vegetation cover, sand winds, are information included in these observations. Nevertheless, these observations usually combine together, making them more or less difficult to extract from the raw data transmitted by satellites. The science of remote sensing consists in interpreting and processing the series of spatial and temporal images in order to extract such parameters, qualitatively or quantitatively. Desertification is a phenomenon of irreversible land degradation. It results from complex processes linked to the coupled and joint evolution of natural and human-induced factors. The beginning, development and results of such processes are materialised by land surface states and their evolution.

Remotely sensed data consequently include information that the science of remote sensing allows to partly extract with more or less accuracy. Such information coupled with others are involved in various stages of the desertification process. Remote sensing provides useful data; some of them are essential information impossible to collect otherwise (especially in terms of homogeneity and spatial coverage and/or temporal monitoring) for early warning, monitoring the development of desertification phenomena and acknowledging a final state. Among others, remote sensing may allow to determine the impacts of policies to combat desertification. However, because of the mentioned limits regarding the extraction of useful parameters and the part played by the latter in the processes concerned, remote sensing turns out to be a tool among others - certainly a powerful one, but not a scientific, decisional or operational “miracle” solution.

After presenting in detail the technique and science of remote sensing and how it allows to monitor various elements of desertification processes, this brochure deals with the most important and significant cases and brings both aspects together. Several key parameters and processes are studied: roughness, albedo, surface temperature, moisture, vegetation indices on the one hand; vegetation cover monitoring, modifications in the land surface composition in dry environments, wind transportation on the other hand. Examples are developed: evolutions of specific sites, projects under way. Lessons taught by previous experiments are critically analysed, options for the future are designed.

    Begni Gérard

    Begni Gérard

    CNES; Terre Environnement Climat - scientifique senior 

    Escadafal Richard

    Escadafal Richard

    Senior scientist IRD at CESBIO, Toulouse (France)

    Fontannaz Delphine

    Fontannaz Delphine

    Ingénieur au service Analyse et produits images, (...)

    Hong-Nga Nguyen Anne-Thérèse

    Hong-Nga Nguyen Anne-Thérèse

    Ingénieur de recherche, CNES (France)

    Begni Gérard, Escadafal Richard, Fontannaz Delphine and Hong-Nga Nguyen Anne-Thérèse, 2005. Remote sensing: a tool to monitor and assess desertification. Les dossiers thématiques du CSFD. Issue 2. 44 pp. CSFD/Agropolis, Montpellier, France.


    La télédétection

    Dossier thématique du CSFD N° 2 • 2005

    La télédétection

    Un outil pour le suivi et l’évaluation de la désertification

Dernières publications publiées

  • Article de synthèse sur les questions de dégradation et de restauration des terres

     • 2017

    Article de synthèse sur les questions de dégradation et de restauration des terres

    Article de synthèse sur les questions de dégradation et de restauration des terres, résumé des séminaires de master de Marc Bied-charreton, à paraître prochainement dans une revue de l'Université d'Auvergne.

    Marc BIED-CHARRETON (...)

    Français
  • A propos de la neutralité en termes de dégradation des terres

    A propos de la neutralité en termes de dégradation des terres

    Philippe Billet, membre du CSFD, vient de publier une note qui fait le point sur ce concept de neutralité d’un point de vue juridique.

    Ce focus est publié dans la revue mensuelle Énergie - Environnement  - Infrastructure (n°10, octobre 2016). Philippe Billet est Professeur agrégé de droit public (Université Jean Moulin - Lyon 3) et Directeur de l'Institut de droit de (...)

    Français
  • La neutralité en termes de dégradation des terres

    Fiche d'actualité du CSFD  • 2016

    La neutralité en termes de dégradation des terres

    La dégradation des terres constitue un frein au développement durable en impactant l’environnement, la sécurité alimentaire, la fourniture de services par les agroécosystèmes et les conditions de vie des populations. C’est un (...)

    Français
  • Ecological engineering

    Fiche du CSFD 11  • 2015

    Ecological engineering

    for sustainable agriculture in arid and semiarid West African regions

    Ecological engineering offers new alternatives for the management of agricultural systems that are more tailored to the ever-changing social and environmental necessities in Arid and semiarid West African regions. This leaflet reviews these innovative (or conventional but improved) (...)

    Egalement disponible en version française
    English
  • Document de travail AFD n° 139 | Indicateurs d’impact des projets de gestion durable des terres, de lutte contre la dégradation des terres et la désertification

    CSFD R&D N° 139  • 2014

    Document de travail AFD n° 139 | Indicateurs d’impact des projets de gestion durable des terres, de lutte contre la dégradation des terres et la désertification

    Ce document, publié dans la collection Document de travail de l’Agence Française de développement (AFD), s’intéresse à la recherche de bons indicateurs pour évaluer les impacts à long terme des actions de (...)

    Français
  • Carbon in dryland soils

    Dossier du CSFD 10  • 2014

    Carbon in dryland soils

    Multiple essential functions

    Soil organic carbon (SOC) has a key role in the overall behaviour of soils and agroecosystems. Increasing its content enhances soil quality and fertility, thus improving agricultural resilience and sustainability and, in turn, food security of societies. Soils also contain the largest pool (...)

    Egalement disponible en version française
    English
  • Carbon in dryland soils

    Fiche du CSFD 10  • 2013

    Carbon in dryland soils

    Multiple essential functions

    This leaflet reviews the essential functions of soil carbon in dryland areas and the reasons why combating desertification allows sustainable agriculture while stoking carbon in soils. Carbon in soils is at the crossroads of the three international environmental conventions.

    Egalement disponible en version française
    English
  • Soil carbon: at the crossroads of the conventions

    Présentation | Publication des membres  • 2011

    Soil carbon: at the crossroads of the conventions

    Agriculture sector is a major source of greenhouse gas, contributing directly 14% of total global emissions. When combined with related changes in land use including deforestation (for which agriculture is a major driver), agriculture’s contribution rises to more than one-third of (...)


    Posté par Bernoux Martial  • 
    English
  • Moussons, sécheresses et dégradation des sols en zone intertropicale

    Publication des membres | Rapport non publié

    Moussons, sécheresses et dégradation des sols en zone intertropicale

  • Pastoralism in dryland areas

    Fiche du CSFD 9  • 2012

    Pastoralism in dryland areas

    A case study in sub-Saharan Africa

    Often barren natural rangelands are directly utilized for pastoral livestock farming, which is by nature mobile (transhumance). This activity is on the rise in sub-Saharan Africa, providing a living for a great number of herders, generating marketable animal products, while also supporting (...)

    Egalement disponible en version française
    English

Contact

CSFD
Comité Scientifique Français de la Désertification
Agropolis International
1000 avenue Agropolis
F-34394 Montpellier CEDEX 5  France
Tél. : +33 (0)4 67 04 75 73 • courriel : csfd@agropolis.fr

Connexion

Connexion


Conception & réalisation : Olivier Piau (Agropolis Productions) - Webmaster : Laurence Monin (Agropolis International)
© 2013-2015 Comité Scientifique Français de la Désertification (CSFD)