Dust storms, dust transfer and depositions in the southern Aral Sea region

Abstract

Land surfaces poor in vegetation coverage and dried out soils are accelerating factors of sand and dust transport. Dust transport also has considerable impact on the human society if highly populated regions are on the transport pathway or sink areas as dust transport can bring pollutants into residence areas. The quantitative prediction of dust storms is impossible unless the entire dust cycle, consisting of dust emission, transport and deposition, can be correctly assessed. In recent years, dust emission schemes have been developed that account reasonably well for the impacts of atmospheric forcing and land-surface properties on dust emission. The Aral Sea disaster has been caused by the overexploitation of the water and land resources and is related to problems of polluted surface and ground water bodies, the loss of agricultural productivity and biodiversity, the regional climate change and also the human health, especially within the disaster zone. Major consequences of the Aral Sea shrinkage, apart from the decrease of its water volume and area, an increase of the water salinity and a modification of the salinity pattern is the formation of a vast saline desert with the area of almost 3.6 mln ha on the exposed seabed. The main factors of dust storm occurrences are the frequency of strong winds and availability of source material in dust emission sites. During the last decades the total area of dust emission sites in the Aral Sea region increased significantly because of the shrinking of the Aral Sea and consequent drying of its exposed bottom and deltaic areas of Amudarya and Syrdarya Rivers.