Aeolian processes and sand encroachment problems in Kuwait

The surface of Kuwait is carved in a calcretized clastic sequence of Miocene-Pleistocene age, mostly covered by a thin blanket of recent aeolian deposits. Fast rate of development and increase of human activities contributed to denudation of the vegetative cover and exposure of dry, loose sediments to wind action. At present, Kuwait is intensively subjected to aeolian actions manifested by frequent occurrences of sand and dust storms. This dictated the need for regional understanding of the magnitude of the aeolian processes, their behavior with man-made establishments, and their long- and short-term impacts. A comparison between the nature and distribution of recent surface sediments in Kuwait in 1979 and 1990 shows significant changes that reflect the work of aeolian processes during this period. The direct impact of the enhancement of aeolian action is represented by the increase in the rate of sediment transport. Transportation of fine-grained particles in suspension frequently occurs during dust storms usually initiated in southern Iraq. The particles migrate over Kuwait as thick dust clouds and finally settle in the northern part of the Arabian Gulf. Bedload transport of sand, or saltation, frequently occurs during summer whenever wind speed reaches 5.4 m/s. The average annual sand drift rate in Kuwait is about 20 m³ (m width)^-1 yr^-1, the majority of the drift occurring during the period May-August, to the southeast. Bedform transport or sand dune movement is also recognized in Kuwait. Sand dunes mostly occur as small barchans of about 3 m height. The measured rate of movement of these barchans varies with height. A barchan of average height usually moves about 20 m in nine monthes (January-August). The remarkable high rate of sand transport and the increase in development activities in the desert areas, are responsible for the enhancement of the sand encroachment problems in Kuwait. Almost all installations, roads, and farms are significantly affected by the accumulation of considerable amounts of aeolian sand. These problems have pronounced adverse environmental and economic impacts.