Characterization of peat deposit using ground penetrating radar: Survey experiments and data interpretation

The paper deals with the possibilities of different wave frequency antennae applications for estimation of the depth of peat deposits and detection of peat layers with different physical characteristics. We employed a GPR system “OKO-2” (“Logical systems”, Russia) with 250 MHz, 700 MHz, and 1700 MHz shielded antennae. The surveys were conducted in 2017–2019 within the pristine and drained raised bogs and swamp forest in the south taiga subzone of Western Siberia to assess the spatial differentiation of the peat deposit and the modern peat accumulation rate within drained bogs. The peculiarities of field surveying, GPR data processing and interpretation are shown. Based on GPR data analysis the influence zone of Bakchar bog and modern peat accumulation within drained bogs were assessed. We noted that the Bakchar bog has a vast zone of influence reaching 700 m from the bog border where peat accumulation is observed. The modern peat accumulation is observed within Bakchar the bog. Drained sites of Ust-Bakchar bog are characterised by the absent peat accumulation or degradation of the peat deposits.

Diurnal and seasonal dynamics of the electrical conductivity of water of the northeastern part of the Great Vasyugan Mire (Western Siberia)

In this study, we determined the diurnal and seasonal dynamics of the electrical conductivity of waters of the northeastern part of the Great Vasyugan Mire in Western Siberia. Our studies showed that the electrical conductivity of the waters for the period of April to September 2016 was characterised by a value of 35 μS/cm, and the seasonal amplitude was 25 μS/cm. In seasonal dynamics, there are three maximums of electrical conductivity in waters. The first maximum was formed in April (48 μS/cm) and is associated with snowmelt water supply. The second one was observed in May after the complete thawing of the peat deposit (39 μS/cm), and the third was observed at the end of July as a result of biochemical processes in the peat deposit (43 μS/cm). Our studies have shown the electrical conductivity hysteresis during time intervals from 3–5 to 6–10 days electrical conductivity remains constant despite the change in hydrometeorological conditions (water table level, temperature).

METHOD FOR PRESENTING THE RESULTS OF OEDOMETER TESTS UNDER A SURVEY OF A PEAT DEPOSIT

The use of the average values of physical and deformation characteristics for the entire extremely heterogeneous peat layer leads to mistakes in estimation a settlement of the embankments set up over it. The results of numerous oedometer tests of peat and empirical equations for calculating the void ratio of peat as a function of its initial value and the load are presented. A new approach to carrying out the geotechnical surveys in a wetland is proposed.

Improving the Reliability of the Scraper-Bunker Peat Harvester

Cases of failures of peat scraper-bunker harvesting machines are analyzed. It has been proven, that the main cause of failures is the stumpiness of the peat deposit. When interacting with the stump, there is a sharp increase in the load on all elements of the transmission of the machine, which leads to their temporary exit from the working state. The first element, that the stump encounters is the machine's elevator bucket. As a result of interaction, the bucket gets damaged in the form of ruptures, incipient and developed cracks. Proposals are formulated to increase the reliability of the scraperbunker peat harvester by installing a simple tracking device at work of the bucket elevator and improving the design of the elevator bucket itself. It is noted, that due to the initiation and development of cracks in the zone of welded seams, buckets must be subjected to flaw detection at least once a year, during pre-season maintenance.

Modernization of Mining Scheme in Developing Peat Deposit

The article presents the results of the study of a peat deposit development scheme with improved spread parameters. The parameters are improved by forming the spread as moulded particles of a certain shape and size determined by the size of moulding machine grooves and the degree of peat relaxation. To obtain such particles a milling cutter is proposed to be replaced by a moulding mill at the stage of peat deposit milling. When excavated, the peat mass is loosened and fed into a roller moulding machine where the rollers, rotating in opposite directions, capture it and the peat is compressed. The loose structure changes into dense particle-particle packing. The circumferential speeds of roller rotations are equal. A trapezoidal groove profile is chosen for the moulded particles to leave it. The groove depth is 10 mm. The uniformity of the moulded enlarged particle distribution over a drying field is characterized by a spread variation coefficient, which allows the spread quality to be evaluated. The enlarged particle spread is normalized by some cumulative actions characterizing the spread by parameters (the thickness, the average particle size, the size uniformity, the number of layers). Therefore, the drying of enlarged particles is intensified and peat yield per unit area is increased.

Investigating peat deposits with ground-penetrating radar – a case study of drained bogs in Western Siberia, Russia

This paper deals with the assessment of the peat deposit transformation of two drained raised bogs (the Bakchar bog drained for forestry and the Ust-Bakchar bog drained for peat extraction) within the Western Siberian taiga zone. Specifically, the objectives of this study were to: 1) characterise the peat deposits of key sites with the use of ground-penetrating radar (GPR) and manual data; 2) estimate the spatial differentiation of modern peat accumulation rates at the microhabitat level. We used the GPR system “OKO-2” with 250, 700, and 1700 MHz shielded antennas and a displacement sensor. We concluded that the use of this GPR complex allowed the assessment of the total depth of the peat deposit, the depth of the fibric peat layer, and the thickness of the layer formed after drainage. We paid attention to defining the patterns of layers formed at depth after drainage within hummocks or hollow microhabitats. The peat accumulation after drainage was not continual throughout all mire surface, which was most typical for plots of the Ust-Bakchar bog. The modern peat accumulation increased 1.3–2.2 times from hollows to hummocks and it was 2–4 times higher within the Bakchar bog than in the Ust-Bakchar bog.

Comparison of bog phytocenosis ecotopes parameters and peat deposit depths of the Beloe bog (Perm region, Russia)

It is known that phytoindication of the nature and depth of peat deposits is possible only when, among other factors, the geographical and geomorphological position of the bog systems is taken into account. The aim of this study is to determine whether or not there is a relationship between peat deposit thickness, phytocenosis composition and ecological parameters of plant habitats, using the example of the Beloe Bog located in the Sylvensko-Irenskaya lowland in the south-east of Perm Krai. Measure ments of the depth of the peat deposit were carried out using a peat probe, followed by the determination of the volumes of the peat bog in the GIS (ArcGIS (ESRI)). The diversity of peatland plant com-munities is described, their ecological-cenotic analysis and phytoindication analysis of ecotopes is carried out using Ellenberg and Landolt ecological scales using EcoScaleWin software. The results allow to update the stock data of geological exploration 1969. Ecological-cenotic and phytoindication analyzes revealed differences between pine-dwarf shrub-sphagnum and birch-menyanthes-sphagnum communities. A Spearman correlation coefficient demonstrated a relationship between peat deposit depths and the proportion of Water-Swamp ecological-cenotic group species in the communities, as well as with a number of ecological parameters of the ecotopes. The use of two different ecological scales revealed inconsistency between them. The article substantiates the chosen spatial tactics for measuring the peatland depth of a small irregularly shaped bog and also calculates the time required to measure the thickness of a conven-tional peat deposit of 1000 hectares. The relationship of this work to ongoing palaeoecological research in Perm Krai is highlighted. A comparison is made between the available data on the Beloe Bog and the results of phytoindication studies of the peatland thickness of Western Siberia known to the authors. The limitations and prospects of a series of similar studies in Perm Krai, which will reveal regional and zonal patterns in the spatial structure of bog communities and their relation to the thickness of peat deposits, are considered.

METHOD OF FORECAST ASSESSMENT OF SAPROPEL AVAILABILITY AT PEAT DEPOSITS OF BELARUS

The paper presents the results of a study of the patterns of distribution of sapropel under a peat deposit. To predict the origin of a peat deposit either on the site of an ancient lake, or formed by waterlogging by statistical methods according to the available set of informative features contained in survey materials, cartographic and geological sources, features are identified by which the initial phase of each object is determined, rules are developed, procedure algorithms are calculated her recognition. The effectiveness of forecasting the origin of the peat deposits.