CORDIS - Forschungsergebnisse der EU


Final Report Summary - CALTER (Long term ecological research program for monitoring aeolian soil erosion in Central Asia)

CALTER is a multinational research project where the participant investigators with various types of spatial information need to share and create cartographic information in a secure way. The goal was to understand the impact of aeolian dust on ecosystems, to establish a long-term monitoring system on current emission sites, to study the frequency of dust storms, the qualitative and quantitative properties of dust / salt deposits and to create effective tools that reclaim man-induced environmental damage. The nature of this phenomenon, the dispersion and different technical backgrounds of user that need to access information about dust-storms creates the need for the development of a unified Geographic information system (GIS) spatial database assessable from the internet (Webgis) system for data storage and analysis.

The CALTER project was structured into six Work packages (WPs), as follows:

WP 1: Coordination and general tasks
The coordination activities carried out by Ben-Gurion University (BGU) included:
- permanent contact with all participants in order to coordinate the activities during the project;
- providing money flow from European Commission to NIS participants via BGU;
- synchronising the 2010 monitoring season in Uzbekistan, Kazakhstan and Turkmenistan;
- organising the spring field work in the testing sites in Karakalpakstan;
- organising the transportation of collected samples from central Asian countries to Germany and Israel;
- preparation of the scientific and financial reports for the fifth year of the project.

WP 2: GIS spatial database setup. Incorporation of the project findings into GIS
A Webgis was created. It was installed into a Linux-Apache-PHP-Mapserver in Israel (Department of Geography and Environmental Development, BGU of the Negev). The solution adopted by the CALTER project was to use the Mapserver system as the Webgis platform, this software is based on the open-source software license therefore it can be used and modified without the need for licensing fees, this solution has a lower Total cost of operation (TCO) compared with Arcims, the TCO can decrease even more when using the Mapserver system in a Linux Operating system (OS) with PostGIS as spatial database. The use of Webgis as tool of research is of fundamental importance when working with disperse users and there is the need of aggregating several types and forms of data so that they can be easily accessed to anyone. The use of Webgis permits the integration, organisation and retrieval of data from any internet access point. The Webgis based on Mapserver-Linux-Apache-PHP-Postgis connection can be flexible enough to store all the data necessary for analysis of the sand-storm phenomena, also the use of this technology is money-saving since all the tools are based on the open-source licensing.

The research on the format of files that could be exchanged in the Webgis and on the security enhancement of our Webgis application has been carried out. From the security tests is can be concluded that the developed defense system of the CALTER Webgis can withstand all common internet attacks.

WP 3: Study frequency, distribution and seasonality of dust / salt storms
The main goal of this work package was to study the frequency, distribution and seasonality of the salty, dust and sand storms based on analysis of the meteorological historical data and data from ground observations.

Analysis of the spatial distribution of dust storms suggested four main source areas of dust storm occurrences, which during the time suffered changes such as shifting and shrinking their spots. The main spatial changes were obvious in the Northern Caspian deserts, where DS occurrence areas shrunk significantly, and also suffered a few hundred kilometres shift to the east. The Karakum and Kyzylkum deserts, as well the south Balkhash Lake area, suffered important surface reduction of the major source areas of DS activities. As the all hotspots of highest DS activities showed decreasing trend of dust emissions, the new Aralkum Desert became very active in the last two decades of the 20th century. Because there are not any ground observations of the new Aralkum, the analysis of the high temporal resolution imagery is required.

The significant decreasing trend of dust storm frequency could be easily explained by the recovery of deserts ecosystems due to reduced anthropogenic activities in the region after 1980s. But as it was mentioned by a large number of researchers, the decreasing trends of DS frequencies were registered worldwide; so the human impact on Aeolian activities in Central Asia may be not a single and / or major factor

WP 4: Characterisation dust emission sites. Land cover / land use change detection using high-resolution imagery.

The research was conducted in the three Central Asian countries: Turkmenistan, Uzbekistan and southern Kazakhstan. The desert areas of Central Asia include territories from the shores of the Caspian Sea in the west, up to the foothills of Alatau, Tian Shan, and Pamir-Alay, to the east and south-east. The dry lands of Central Asia cover a total area of 1890 million square kilometers with a human population of almost 40 million.

The NOAA-AVHRR satellite database had been updated in 2010. Nineteen dust storm events had been registered in January - November 2010. 143 dust storm events were registered in the Aral region during 2000 - 2010; the highest number of dust storms was registered in 2002, 2003 and 2010 - 22, 19 and 19, respectively. Satellite dust storms database was supplemented by Landsat (1972 - 2010) archive.

One of the earliest satellite images with dust storm was found (7 October 1972), which shows the dust emission from the degraded plots around watering points. The dust emission area in the Aral region is permanently expanding as a result of continuous drying of the sea. It is significant to note that the areas of the dried bottom exposed in the previous years stay active during all the period of exposure. Vozrozhdenie Island, which is connected now to the mainland, is new active source of dust aerosols.

The dynamics of changes in the area of the Aral Sea had been studied by NOAA-AVHRR imagery (2000 - 2010). It was revealed that area of water in 2009 decreased by 60 % regarding to that in 2000, mainly on expense of the Eastern Aral Sea - the shallowest part of the Sea. In 2010, there was slight increase in the Aral Sea area due to the water inflow from the Uzbekistan (south-eastern) part via one of the channels of Amudarya River.

Just after visual comparison with the reference land cover map, both classification approaches (Image algebra and supervised classification) are highly reliable: the trend of the topsoil transformation is similar in both cases.

WP 5: Study the potential sand drift using model and real wind data, model dust / salt transportation
Since little research has been conducted regarding the aeolian geomorphic processes of sand seas in Central Asia and the cause for stabilisation of these fields, this research is aiming to map the sand seas, identify the major dune types and large morphologies using remote sensing imagery. The chronology of the effect of climatic changes on mobility and stability of the central Asian sand seas is done by luminescence dating.

Study area: The sand seas of Central Asia are located in the Turan Lowland in the countries of Turkmenistan, Uzbekistan and Kazakhstan, and are known as the Kara Kum and Kyzyl Kum. The sand dunes overlie Quaternary and Neocene alluvial deposits.

From the primary results of this research several conclusions can be drawn:
The ergs in the study area are mostly stabilised, and the estimated sand covered area for the Kara-Kum desert is approximately 260 000 square kilometers and approximately 195 500 square kilometers for the Kyzyl-Kum desert. Although the climate of the ergs is defined as arid, precipitation is above the minimal threshold for vegetation under the current low wind power (DP). Central Asian Ergs are currently stabilised because of a climatic change that occurred during Mid-Holocene. Further classifications of imagery suits from different years and change detection procedures will enable monitoring of sand patches and alternations along the years. In order to further support our analysis, additional samples were gathered during the second expedition in 2009 for further OSL analysis and stabilisation determination of the Central Asian sand seas.

WP 6: Elaboration recommendations for phyto-ameliorative measures in the active and potential dust / salt emission sites
The specific objective for the last period of the report was to analyse the climate changes and their effect on vegetation recovery in the Pre-Aral region. It included several tasks: 1) comprehensive analysis of climate changes as based upon processing of statistical data obtained in meteorological stations; 2) study of microclimatic conditions by original devices to record temperature and moisture in plantations on solonchaks; 3) study the dynamics of soil salinisation in solonchaks developed on the dried sea bottom and the river floodplain; 4) study the dynamics of the vegetation cover as related to soil salinisation.

In the long-term dynamics of air temperature, there is a tendency towards increasing the mean (by 0.4-3.6 degrees Celsius), absolute minimum (by 1.2-7.5 degrees Celsius) and absolute maximum (by 1.2-4.1 degrees Celsius) temperatures for a year, half a year and a season. The mean temperature reveals the highest changes within the above periods.

Only reliable positive trends have been established in the long-term dynamics of the precipitation and air temperature in all the meteorological stations of the Pre-Aral region. The tendencies towards the changes in the distribution of precipitation and air temperature identified in the Southern Pre-Aral region and adjacent territories of Middle Asia seemed very similar, being characterised by increasing the heat in the summer, lengthening the warm period of time as well as by the rise in temperature within the annual cycle and summary values of atmospheric moisture especially in the cold six months and the winter-autumn seasons of a year.

A combined analysis of D.A. Pedya's aridity indices (I Pedya1 and I Pedya2) showed that the only increasing tendency identified in the Southern Pre-Aral region and adjacent territories of Middle Asia is the increase in the aridity accompanied by a higher deficit of moisture in the warm period of time at the expense of the autumn, spring and summer seasons of a year.

For purposes of phytomelioration, the rise in winter temperature equaled to increasing the precipitation in the winter may be considered as a positive factor in the Southern Pre-Aral region, whereas the significant fall in spring temperature and the increase in the precipitation in the spring and rainfalls in the summer make difficulties for the planting works.

Taking into account the changeable weather in the Pre-Aral region in view of climate changing and increasing the aridity and continentality of microclimatic conditions in field as compared to the data of meteorological stations, the phytomelioration of solonchaks should be implemented only in periods of forecasting the favourable weather conditions.

The vegetation shaded the bare solonchaks in the southern part of the Pre-Aral region favourably affects on the microclimatic conditions of biotopes both in their terrestrial and subsoil parts: the air and soil temperature becomes lower to the depth of 100-150 cm during the vegetation period.

Without artificial (constant) moistening in the upper soil horizons the phytomelioration of automorphic solonchaks is impossible under the recent climate conditions (trends to increasing the hot and decreasing the precipitation in the summer-autumn period).

Based upon a comprehensive analysis of changes in soil salinity taken place for a year and for several years in Southern Pre-Aral region, it seems reasonable to conclude that automorphic solonchaks of marine and alluvial origin reveal intensive natural dissolution in periods of higher precipitation due to climate changes.

The salinity in different horizons of solonchaks is quickly and highly changed (by 1.5 to 3 times) under natural conditions both from year to a year and from season to a season, what is manifested to a considerable extent through changes in several-years periods of maximum and minimum atmospheric moistening. The greatest changes (by 6-8 times) are observed as affected by artificial flooding