# Sand and Dust Storms: Impact Mitigation
## 3 The Scale of SDS Impacts: Countries Affected  
There have been several attempts to assess desert dust sources globally [20; 21; 22], compiled using data from satellite borne sensors and terrestrial meteorological stations. These analyses have provided us with a good, though not perfect, understanding of where the planet's major contemporary atmospheric soil dust sources are situated. The most active sources are located in the Northern Hemisphere, mainly in a broad dryland Dust Belt that extends from the west coast of North Africa, across the Middle East, to South, Central and Northeast Asia. Drylands in the Southern Hemisphere are much less active SDS sources, despite concentrations of activity in Central Australia, Southern Africa and the Atacama in South America. These sources have significant local impacts--as does the North American Great Basin--but remain relatively minor on the global scale. There are also numerous locally significant areas of SDS activity in high-latitudes [23]. In addition to these sources, we know of numerous areas--many outside drylands--where wind erosion occurs due to human mismanagement of resources, particularly on agricultural fields and of large water bodies. For instance, soil erosion by wind is a particular threat on arable land in Europe [24], not only in semi-arid Mediterranean areas [25] but also in the temperate regions of northern countries [26]. There have also been attempts to map such areas. The global assessment of soil degradation (GLASOD) produced a world map of human-induced soil degradation, which included data on wind erosion that can be disaggregated to show a world map of human-induced wind erosion [27]. More recent assessments have also been made in certain regions, such as Europe [28]. We have considerable knowledge of long-distance desert dust transport pathways from many of these numerous sources of wind-blown surface material. Desert dust is commonly transported over thousands of kilometers through the troposphere and hence affects atmospheric, biological and geochemical conditions at great distances from dust sources. The global pattern of major dust transport pathways is depicted in Figure 1 along with estimates of emissions from major source regions and deposition to the oceans. Figure 1: Main routes of desert dust transport (light blue arrows) and locations of the major dust sources: (1) Sahara; (2) Arabia; (3) Asia; (4) North America; (5) South America; (6) Southern Africa; and (7) Australia, depicted using global means of the measured daily TOMS Aerosol Index values (1979-2011). Dust emissions from different regions in Mt are indicated by red arrows and deposition to the oceans in Mt is indicated by dark blue arrows. Adapted and modified from [2; 29]. Saharan dust, for instance, has been monitored across West Africa [30], as well as much further afield, including northern Europe [31], the Caucas Mountains [32], Caribbean islands [33], North America [34], and South America [35]. Indeed, the Earth system effects of dust from the Sahara--the planet's largest source of desert dust--are plentiful. They include impacts on the atmospheric radiation balance [36], regional precipitation [37], hurricane activity [38], sea surface temperatures [39], marine primary productivity [40], health of coral reefs [41], terrestrial primary productivity [35], lake-water chemistry [42], and soil formation [33]. Dust from northeast Asian deserts, another major source, is frequently transported over the Korean Peninsula and Japan [43], across the Pacific Ocean to the North American continent [44], Europe [45] and on occasion even further [46]. Antarctica receives deposits of desert dust from Patagonia and Australia [47] and material from farmland in Ukraine has been traced to Central Europe [48].