Following dust in the wind
The ‘Long term ecological research program for monitoring aeolian soil erosion in Central Asia’ (Calter) project aimed to set the groundwork for long-term ecologic monitoring of Central Asia where natural conditions give rise to sand and dust storms. Together with large-scale anthropogenic changes, the phenomenon has resulted in the formation of new salt/dust-emitting sites. Project partners thus set out to investigate the temporal and spatial patterns of airborne salt-dust deposition across the region and model the current and future trends of aeolian processes there. Calter’s main strategic objective focused on environmental protection to be supported by desertification measures in relevant Central Asian Newly Independent States (NIS). Efforts centred on capacity building of target countries will further strengthen this approach. Research carried out in Kazakhstan, Uzbekistan and Turkmenistan – the three largest Central Asian states – initially involved establishing a spatial database for monitoring the region. The Internet-accessible Geographic Information System spatial database (WebGIS) enabled participant investigators to share and create cartographic information based on their own spatial information. Archive data from meteorological stations in Central Asia as well as remote sensing data were analysed using the PC-installed ArcGIS system. Observation sites were set up for monitoring the quantitative and qualitative characteristics of dust deposit along the north-south and west-east gradients. A dust sampler was used to analyse collected dust samples both and climatic parameters were collected at locations with dust traps. Spatial and temporal distribution charts were drawn up based on averages of three specific periods in time, starting from 1936 until 2003, to study the frequency, distribution and seasonality of Central Asia’s salty, dust and sand storms. Data analysis indicated a clear downward trend of dust storm frequency across the region, which can be explained by the recovery of desert ecosystems as a result of fewer anthropogenic activities there after the 1980s. However, such decreasing trends have also been noted worldwide, implying that the human factor may not be the overriding one. Other project work included the daily monitoring of dust storms by remote sensing imagery and maps of landscape dynamics were built for monitoring land cover changes on the dried bottom of the Aral Sea. The latter sets the basis for monitoring future changes. Model and real wind data were used to study potential sand drift in the region as well as its spatial variability. Use of the physical-statistic model for sand storms will allow detailed assessment of the intensity of deflation and transport of dust aerosol beyond the Aral Sea’s dried bottom. Recommendations were elaborated for phyto-ameliorative measures in active dust-salt emission sites as a means of reducing the volume of blown sand and salts-dust. Lastly, partners set up experimental plots for testing salt and drought-tolerant plants in a specific river area. The five model ecological profiles were monitored on a yearly basis for the duration of the project and of soil and surface water samples were collected and analysed. The information generated will help advance measures that can be taken to alleviate the effects of sand and dust storms in Central Asia, as well as be used as a basis for future monitoring and assessments.
