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Stathakis D.,University of Thessaly | Perakis K.,University of Thessaly | Savin I.,Vv Dokuchaev Soil Science Institute
International Journal of Remote Sensing | Year: 2012

Urban populations are expanding rapidly and so are cities. Remote sensing offers a convenient means of monitoring this expansion as it covers a period of 40 years in the case of the LANDSAT satellite. In some parts of the globe, this is probably the only viable means of monitoring due to the lack of other types of data. In order to monitor expansion, first, urban land has to be separated from other land-cover types. Although this can be done by standard classification processes, it is much more efficient to establish an urban index (UI) analogous to the widely used normalized difference vegetation index (NDVI) for vegetation. Existing efforts to establish such a UI are reviewed and compared in a common context. Following this, a novel, more efficient UI is introduced. The calculation of the new index is straightforward, based on combining the NDVI with the normalized difference built-up index. The results are promising as the index can efficiently segment urban areas, even in the presence of excessive bare land. The proposed method is evaluated on two test sites selected in different LANDSAT scenes. The new index is valid only for sensors with the same bands as those of LANDSAT. © 2012 Copyright Taylor and Francis Group, LLC. Source

Korobova E.M.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry | Linnik V.G.,RAS Vernadsky Institute of Geochemistry and Analytical Chemistry | Chizhikova N.P.,Vv Dokuchaev Soil Science Institute | Alekseeva T.N.,RAS Shirshov Institute of Oceanology | And 3 more authors.
Journal of Geochemical Exploration | Year: 2014

A detailed study of soil fractions of different sizes and their mineralogy was performed to explain the distributions of 137Cs discharged by the Krasnoyarsk MCC in alluvial soils of the near and remote impact zones. Radionuclides were shown to concentrate in fine fractions enriched in hydromica and smectite. However, in natural conditions the dominant size fractions responsible for 137Cs accumulation appeared to belong to sizes from silt (0.010mm) to clay (0.001mm). Ultrasonic treatment helped to reveal that this occurs due to natural water-resistant aggregation of smaller particles. Aggregation of fine particles and a considerable contribution of coarse fractions to the total sample mass lead to a smoothing effect in the distribution of 137Cs inventory in different fraction masses constituting the soil layer. However, clay fractions <0.001mm, and aggregates sized 0.05(0.63)-0.010mm and 0.25-0.125mm appear to dominate in radiocesium storage in the studied layers supporting the contention that these fractions play a major role in the distribution and accumulation of technogenic contamination in the floodplain soils of the region.Mineralogical analysis of the samples proved that floodplain sediments are able to fixate cesium due to the presence of smectites, illite, feldspars and micas in fines and coarser fractions. Abundant feldspar transformed to sericite can also contribute to cesium sedimentation. The particle interval from <. 0.001 to 0.010. mm would appear to be crucial for contamination levels of river sediments and floodplain soils as they are comparatively resistant in aqueous solution and prone to easy transport by the river. Therefore the alluvial soil fractions of these sizes are of prime importance in the studies of technogenic contamination of river systems. © 2014 Elsevier B.V. Source

Rembold F.,European Commission - Joint Research Center Ispra | Atzberger C.,University of Natural Resources and Life Sciences, Vienna | Savin I.,Vv Dokuchaev Soil Science Institute | Rojas O.,Food and Agriculture Organization of the United Nations FAO
Remote Sensing | Year: 2013

Low resolution satellite imagery has been extensively used for crop monitoring and yield forecasting for over 30 years and plays an important role in a growing number of operational systems. The combination of their high temporal frequency with their extended geographical coverage generally associated with low costs per area unit makes these images a convenient choice at both national and regional scales. Several qualitative and quantitative approaches can be clearly distinguished, going from the use of low resolution satellite imagery as the main predictor of final crop yield to complex crop growth models where remote sensing-derived indicators play different roles, depending on the nature of the model and on the availability of data measured on the ground. Vegetation performance anomaly detection with low resolution images continues to be a fundamental component of early warning and drought monitoring systems at the regional scale. For applications at more detailed scales, the limitations created by the mixed nature of low resolution pixels are being progressively reduced by the higher resolution offered by new sensors, while the continuity of existing systems remains crucial for ensuring the availability of long time series as needed by the majority of the yield prediction methods used today. © 2013 by the authors; licensee MDPI, Basel, Switzerland. Source

Breulmann M.,Helmholtz Center for Environmental Research | Masyutenko N.P.,All Russia Research Institute of Arable Farming and Soil Erosion Control | Kogut B.M.,Vv Dokuchaev Soil Science Institute | Schroll R.,Helmholtz Center Munich | And 4 more authors.
Science of the Total Environment | Year: 2014

The quality, stability and availability of organic carbon (OC) in soil organic matter (SOM) can vary widely between differently managed ecosystems. Several approaches have been developed for isolating SOM fractions to examine their ecological roles, but links between the bioavailability of the OC of size-density fractions and soil microbial communities have not been previously explored. Thus, in the presented laboratory study we investigated the potential bioavailability of OC and the structure of associated microbial communities in different particle-size and density fractions of SOM. For this we used samples from four grassland ecosystems with contrasting management intensity regimes and two soil types: a Haplic Cambisol and a typical Chernozem. A combined size-density fractionation protocol was applied to separate clay-associated SOM fractions (CF1, <1μm; CF2, 1-2μm) from light SOM fractions (LF1, <1.8gcm-3; LF2, 1.8-2.0gcm-3). These fractions were used as carbon sources in a respiration experiment to determine their potential bioavailability. Measured CO2-release was used as an index of substrate accessibility and linked to the soil microbial community structure, as determined by phospholipid fatty acids (PLFA) analysis.Several key factors controlling decomposition processes, and thus the potential bioavailability of OC, were identified: management intensity and the plant community composition of the grasslands (both of which affect the chemical composition and turnover of OC) and specific properties of individual SOM fractions. The PLFA patterns highlighted differences in the composition of microbial communities associated with the examined grasslands, and SOM fractions, providing the first broad insights into their active microbial communities. From observed interactions between abiotic and biotic factors affecting the decomposition of SOM fractions we demonstrate that increasing management intensity could enhance the potential bioavailability of OC, not only in the active and intermediate SOM pools, but also in the passive pool. © 2014 Elsevier B.V. Source

Savin I.,Vv Dokuchaev Soil Science Institute | Stolbovoy V.,Vv Dokuchaev Soil Science Institute
GlobalSoilMap: Basis of the Global Spatial Soil Information System - Proceedings of the 1st GlobalSoilMap Conference | Year: 2014

Newly established Unified National Register of the Soil Resources of Russia (UNRSR) contains four parts: Soils, Soil resources, Soil-ecological regionalization and Soil data. Soil part originates from digitized version of 1:2 500 000 soil map of Russia. It contains 206 soil typological units, 70 soil complex's, a variety of textural classes which all together describes nearly 26 000 soil mapping unites. Soil resources describe soils of the administrative regions or Subjects of Russian Federation. Further data collection will be intensified in the Subjects of RF. The introduction of the UNRSR into the GlobalSoilMap project will be done by means of soil correlation. Due to limited application of the WRB globally, we propose to apply the US Soil Taxonomy. Heterogeneity of soil sampling is another issue which we have to be discussed. © 2014 Taylor & Francis Group, London, UK. Source

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