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Described case study is a part of research project focused on investigation of the capabilities and techniques of microrelief mapping based on different data sources. The case study was conducted to estimate the effectiveness and accuracy of microrelief mapping using the multitemporal very high resolution satellite images. Used test area is located at North-Western Russia (Leningrad region, Tosna river basin). GigitalGlobe's WorldView-1 and 2 satellite images were used. The DSM modelling, DSM accuracy estimation and microrelief structures interpretation were conducted.

The paper describes case study, which we conducted using test area located in Central European Russia (Orel region, Suhaya Orlitsa river basin). The archived topographic (cartographic) data, data of topographic survey and satellite imagery were used as study materials. We have estimated the accuracies and limits of microrelief interpretation basing on the cartographic and survey materials. Derivative geomorphometric maps were used as enabling tool for interpretation of the microrelief strictures. Very high resolution space satellite imagery were used as reference data.

Estimation of P2O5 (mobile phosphorus) distribution in the arable soil layer is significant when planning effective application of phosphorous fertilizers. Additionally, it is necessary to understand soil erosion impact onto the P2O5 variability in soil material. We conduct our study in the experimental area located in the basin of Sukhaya Orlitsa River (European part of Russia, Orel region, Orel district). The territory belongs to the periglacial zone of the Russian plain, where the paleocryogenic landforms are presented (block elevations, inter-block depressions of watershed surfaces, ravine complexes on the slopes). The paleocryogenic microrelief is clearly visible on very high resolution satellite imagery. Chernobyl origin caesium-137 acts as a marker of washed gray forest soils, and makes it possible to estimate a soil washout degree. The study is aimed onto design of GIS-based methodology for estimation of washout and redistribution of the soil material and its components. The use of 0.5-1 m/pix satellite imagery, GIS-based representation and analysis (GIS is a Geographic Information System), gamma-spectrometric and agrochemical analyses allowed us to draw the following conclusions. In poorly washed soils in block elevations and watersheds of micro-ravines a caesium-137 reserve in under-plowing soil layer (layer under 24-25 cm) does not exceed 4-10%. Mobile phosphorus content in the arable soil layer in these areas is low (less than 8 mg/100g). It can be explained by the repeated plowing and moving of soil on the blocks and watersheds of micro-ravines, reduced soil moisture, and low content of organic material in the soil (humus content is less than 4%). Additionally, we made a number of experiments confirmed that the content of mobile phosphorus in the arable soil layer of micro-ravine thalwegs is higher than in watersheds (for washed and washed/washed-in soils). Our hypothesis assumes that in wet plowing furrows and micro-ravines the remains of agricultural plants are buried and decomposed (humus content here is more than 4%). Consequently, the phosphoric acid compounds are accumulated in the arable horizon of thalwegs, and P2O5 content here reaches 15-21 mg/100 g.