Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Determining Potential Herbage Production in the Sahel

Auteur : Anderson John Curtis

Université de soutenance : South Dakota State University

Grade : Master of Science (MS) Geography 1983

Résumé
The study illustrates a method to estimate the distribution of potential herbage production over large areas of the African Sahel under varying climatic conditions. The exploration of the method began after consulting with Mr. Albert A. Klingebiel. As a result of the discussion the study is determined to be practicable based upon the following three points : 1) potential herbage production is not known for large areas of the Sahel ; 2) the spatial distribution of potential, herbage production varies with differences in soil characteristics and in amount of precipitation ; and 3) potential herbage production is known for the soil associations of an area of the Sahel in the Republic of The Sudan (informally The Sudan) receiving average annual precipitation. The study tests a procedure to estimate potential herbage production in an area of the Sahel where soils and precipitation regime are considered similar to The Sudan Sahel, but where no statistical data on range productivity are available. A basic assumption to the procedure is that analagous habitats will produce similar amounts of herbage. The method also is designed to estimate potential herbage production for above average and below average annual precipitation levels. A mathematical concept is employed to estimate potential herbage production which is above or below average. The applicability of the mathematical concept was confirmed by Dr. James Lewis. The method requires that remote sensing techniques be used to determine the characteristics and extent of the soil associations in the study area. Remotely sensed data derived from Landsat satellite multispectral imagery provide the user with environmental data over large areas. The large area coverage is the key to obtaining the information on which a small-scale estimate is based. The area chosen for study is the Sahelian Zone of the Islamic Republic of Mauritania. The Sahel of Mauritania was chosen because potential herbage production is not known for the area while soil association characteristics and precipitation data are known.

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