Desertification, the creation of desert-like conditions where none had existed before, is the result of the vagaries of weather and climate or the mismanagement of the land or, in most cases, some combination of both. such ecological deterioration in the sahel has been linked in several ways to the increased size of livestock herds. during the fifteen years preceding 1968, a period of extremely favorable rainfall, the pastoralists moved into the marginal regions in the north with relatively large herds. however, with the onset of a series of dry years beginning at the end of the rainy season in 1967, the pastoral populations found themselves overtaxing very marginal rangelands, with the result that the nomads viewed themselves as victims of a natural disaster. the mistaken idea that drought is an unexpected event has often been used to excuse the fact that long-range planning has failed to take rainfall variability into account. people blame the climate for agricultural failures in semiarid regions and make it a scapegoat for faulty population and agricultural policies.
the author is primarily concerned with
(a) criticizing a social attitude.
(b) suggesting an approach to solving a problem.
(c) explaining the mechanics of a process.
(d) defending the theories of ecological scientists.
(e) establishing criteria for an experiment.