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Aeolian dust deposition in the Aral Sea region – a spatial and temporal analysis of an ecological crisis

Michael Groll 1, Christian Opp1, Tom Lotz1 ,2, Ilkhom Aslanov1
1University of Marburg, Marburg, Hessen, Germany, 2Chinese Academy of Sciences, Nanjing, China

In combination with the desiccation of the Aral Sea and the formation of the Aral Kum, the dry sea bed became a new source for dust and sand storms. Due to the highly continental climate and the effects of the global climate change in the region, increasing air pressure differences lead to an increasing frequency of high intensity wind events. The resulting aeolian dust movements can be tracked and split into short and long distance transfers using remote sensing approaches, but hard data about the spatial and temporal distribution of the dust deposition requires excessive ground research and thus is scarce. Therefore, we have analyzed the passive dust deposition data from 23 meteorological stations and assessed the spatial and temporal transfer patterns within several transects from the banks of the former Aral Sea in eastern and southern directions covering parts of Kazakhstan, Uzbekistan and Turkmenistan. Dust was collected on a monthly base as well as during specific dust storm events between 2003 and 2012 in the framework of three research projects for both long-term and event based deposition data.
Dust transfer in southern direction was the most important trajectory and the newly formed Aral Kum proved to be an important source region for aeolian dust (besides the natural deserts Kyzyl Kum and Kara Kum). Stations close to these source regions frequently showed deposition rates exceeding international thresholds, resulting in possible negative effects on human and livestock health while the mineralogical and chemical composition of the deposited material influences the arable land in this arid region. This presentation will summarize the most important findings from the three research projects and discuss measures to reduce the wind erosion in the Aral Kum.