干旱区生态环境知识资源中心

In this paper, I firstly describe wind erosion, the primary cause of the desertification in the Sahel region, from three different perspectives - namely, on microscopic (a few centimeters), mesoscopic (a few tens of meters to a few hundred meters) and macroscopic (a few kilometers to a few tens of kilometers) scales to offer a multilateral description of the realities of desertification. The desertification in the Sahel region can be understood on a microscopic scale as a deterioration of soil properties, caused by the loose sand layer being blown away by the wind, and by the associated exposure of the crust (layer); on a mesoscopic scale as a phenomenon that involves the topsoil and its component nutrients being spatially localized to an area not available for crop production; and on a macroscopic scale as a phenomenon in which the land becomes patchy with decreasing vegetation and eventually turns into bare land. Then, I introduce a new countermeasure against desertification, called the fallow band system. It is a technique on a microscopic scale that can be used to cover the crust (layer) by placing a loose sand layer on top of it without investing in capital or labor, and on a mesoscopic scale that can be used to connect the spatially localized topsoil and its nutrients with crop production. Finally, I mention future research needs.