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Deformation analysis in central west Bulgaria using triangulation and GPS data

Abstract

The article discusses a method applied for combining the results of Global Navigation Satellite Systems (GNSS) and 75-year old triangulation measurements to estimate the crustal movements in central western Bulgaria region. It was examined for joint analysis based on the results of GNSS with angular measurements of the first order triangulation network in Bulgaria during the period 1923–1930 year. As a result of the processing of GNSS and angular measurements, horizontal velocities of 15 points, strain rates, and rotation rates have been obtained. The results show dominating N–S extension at a rate of 1–2 mm/y and the deformation is not uniformly distributed over the studied area. The obtained results indicate the possibility of using old angular measurement of first-order triangulation points, together with GNSS data, to obtain estimates of the horizontal crustal movements.

Open access
Exploring the social interest in agritourism among the urban population of Kazakhstan

Abstract

The article examines the issues surrounding tourist activity and social interest in agritourism among residents of the main cities in Kazakhstan. Based on the survey results among a group of n = 577 respondents, the article inspected the extent of their participation in rural tourism, including agritourism, as well as their preferences and expectations regarding the type and extent of services offered on tourist farms. Research results show that the interest of city residents in using agritourism farm services is limited despite of a generally positive attitude towards rural tourism. Potential tourists’ expectations of agritourism farm services focus primarily on the quality of accommodations and the sanitary conditions present in the facilities providing them. Domestic tourists especially expect to be able to take advantage of natural products with medicinal and cosmetic properties. They view active forms of leisure as a mere supplement. The respondents’ opinions and assessments can determine the ways agritourism farms adapt to this clientele as well as impact organisational decisions and strategic planning of rural tourism in the country.

Open access
Retrospective mapping of the XVI century Samtskhe-Javakheti viticulture and fruit farming

Abstract

The presented work deals with the spread of viticulture and fruit farming in the Middle Ages in the Samtskhe-Javakheti region in Georgia. The current state of the farming sectors mentioned and those pivotal moments in Georgian history that had an influence on agriculture are also considered in the article. The changes that determined the viticulture geography from the second part of the 16th century up to the present day are also discussed. The study is mainly based on the census document created in 1574. The article represents the geographic distribution patterns of vineyards and orchards, as well as wine production capacity and the fruit harvest. Retrospective mapping made it possible to restore the distribution of farms and gardens of the mentioned period and to analyse the importance of viticulture and fruit farming in the 16th century. The maps represented show spatial patterns of vineyards, gardens, and main terroirs.

Open access
Influence of Humidity on the Energy of Specific Strain in the Process of Loading Sedimentary Rocks

Abstract

This article presents the results of tests on the energy properties of sedimentary rocks in the Upper Silesian Coal Basin. The rocks were tested both in an air-dry state and in a water saturation state. Samples of sedimentary rocks were collected from boreholes drilled in the underground workings of coal mines located within the area of the city of Jastrzębie, in the areas of the Chwałowice Trough and Rybnik Trough (south-western part of the Upper Silesian Coal Basin) and in the Main Trough. Influence of saturation condition on the values of the tested energy parameters was observed. The values of elastic energy and dissipated energy obtained for the samples tested in water saturation were lower compared to the values obtained for samples tested in air-dry state. As observed, an increase in the values of the given types of specific energy corresponds to an increase in the uniaxial compression strength in air-dry state and in water saturation state. Results of the tests are original and they can be applied while analysing the possibility of the occurrence of some dynamic phenomena and hazards in mine workings in Carboniferous rock mass in the Upper Silesian Coal Basin, caused by mining operations.

Open access
Setup of axial bearing capacity of open ended tubular steel piles driven in sand

Abstract

This paper focuses on the setup of axial bearing capacity of open ended tubular steel piles that are used for offshore foundation systems such as those of wind turbines. A comparative evaluation of the most commonly used models for setup prediction shows an upper estimate bound and a lower estimate bound, which correspond approximately to a setup rate of 60% increase per log cycle of time and 20% increase per log cycle of time, respectively. This finding is validated with the results of case histories reported in literature, which show that the setup values of most case histories considered lie in the best estimate zone between the upper estimate zone and the lower estimate zone. The analysis results show a minimum setup factor of approximately 1.5 for 100 days following end of driving of open-ended tubular steel pile driven in sand.

Highlights

  1. Detailed presentation of setup phenomenon in granular sand and contributing mechanisms
  2. Detailed presentation of setup prediction models in granular sand
  3. Demonstration of lower bound, best estimate bound and upper bound for setup prediction
  4. Compilation of case histories of setup for driven open ended pile in granular soil and validation of lower estimate, best estimate and upper estimate zone

Open access
Application of artificial neural networks in predicting voter turnout based on the analysis of demographic data

Abstract

The author presents the results of research on the use of artificial neural networks in predicting voter turnout. He describes the principles of operation of artificial neural networks, as well as detailed results of two machine learning methods used to predict voter turnout. The research resulted in creation of a functional model that allows for prediction of voter turnout results with a considerable degree of accuracy. The entire research process was carried out using the cartographic research method.

Open access
Spatio-temporal dynamics of vegetation cover in North-West Algeria using remote sensing data

Abstract

Land cover change is the result of complex interactions between social and environmental systems which change over time. While climatic and biophysics phenomena were for a long time the principal factor of land transformations, human activities are today the origin of the major part of land transformation which affects natural ecosystems.

Quantification of natural and anthropogenic impacts on vegetation cover is often hampered by logistical issues, including (1) the difficulty of systematically monitoring the effects over large areas and (2) the lack of comparison sites needed to evaluate the effect of the factors.

The effective procedure for measuring the degree of environmental change due to natural factors and human activities is the multitemporal study of vegetation cover. For this purpose, the aim of this work is the analysis of the evolution of land cover using remote sensing techniques, in order to better understand the respective role of natural and anthropogenic factors controlling this evolution.

A spatio-temporal land cover dynamics study on a regional scale in Oranie, using Landsat data for two periods (1984–2000) and (2000–2011) was conducted. The images of the vegetation index were classified into three classes based on Normalized Difference Vegetation Index (NDVI) values and analysed using image difference approach.

The result shows that the vegetation cover was changed. An intensive regression of the woody vegetation and forest land resulted in -22.5% of the area being lost between 1984 and 2000, 1,271 km2 was converted into scrub formations and 306 km2 into bare soil. On the other hand, this class increased by around 45% between 2000 and 2011, these evolutions resulting from the development of scrub groups with an area of 1,875.7 km2.

Open access
Use of Spectral Indices to Identify the Changes in the Vegetation Community Over Time After Restoring a Palustrine Wetland: a Case Study of Spencer Island Regional Park, Everett, WA

Abstract

Wetland restoration can be measured over time using community vegetation as an effectiveness indicator of restoration actions. Spencer Island Regional Park is part of the tidal freshwater wetlands along the Snohomish river basin. Those wetlands are part of a complex ecosystems, in which they are included as a salmon corridor. This research analyzes the vegetation community changes over time after restored in 1996 on Spencer Island Regional Park, Everett, Washington State, U.S. I analyzed three spectral indices using segmentation and supervised classification of land cover from 1997 to 2018. I found that in the last 21 years, the areas with emergent palustrine vegetation and forests increased, in contrast to diminishing areas of upland and scrub-shrub classes. Those finds can be interpreted that the community vegetation advanced to higher wetland successional stages as upland areas have been colonized by emergent wetland plant communities. A linear regression model predicted that by 2025, the difference between emergent and upland classes should increase. Empirical evidence is presented that support the integration of spectral indices to identify changes in community vegetation. However, it is recommended for future studies to include spectral indices and spatial information for soil and hydrology to deepen these results.

Open access
Hydraulic Characterization of a Self-Weight Compacted Coal

Abstract

Water infiltration through coal stocks exposed to weather elements represents a key issue for many old mining sites and coal-fired power plants from the environmental point of view, considering the negative impact on human health of the deriving groundwater, soil and air pollution. Within this context, the paper investigates the hydraulic behaviour of a self-weight compacted unsaturated coal mass and its impact on the numerical prediction of infiltration induced by rainfall events. In particular, the work focuses on the experimental investigation carried out at different representative scales, from the grain scale to physical modelling. The material, when starting from uncompacted conditions, seems to be characterized by metastable structure, which tends to collapse under imbibition. In addition, direct numerical predictions of the seepage regime through a partially saturated coal mass have been performed. As the compaction of the coal stock induced by dozers has not been taken into account, the numerical simulations represent a conservative approach for the assessment of chemical pollution hazard associated to water infiltration into a real stockpile under operational conditions.

Open access
Topographic surface modelling using raster grid datasets by GMT: example of the Kuril–Kamchatka Trench, Pacific Ocean

Abstract

The study area is focused on the Kuril–Kamchatka Trench, North Pacific Ocean. This region is geologically complex, notable for the lithosphere activity, tectonic plates subduction and active volcanism. The submarine geomorphology is complicated through terraces, slopes, seamounts and erosional processes. Understanding geomorphic features of such a region requires precise modelling and effective visualization of the high-resolution data sets. Therefore, current research presents a Generic Mapping Tools (GMT) based algorithm proposing a solution for effective data processing and precise mapping: iterative module-based scripting for the automated digitizing and modelling. Methodology consists of the following steps: topographic mapping of the raster grids, marine gravity and geoid; semi-automatic digitizing of the orthogonal cross-section profiles; modelling geomorphic trends of the gradient slopes; computing raster surfaces from the xyz data sets by modules nearneighbor and XYZ2grd. Several types of the cartographic projections were used: oblique Mercator, Mercator cylindrical, conic equal-area Albers, conic equidistant. The cross-section geomorphic profiles in a perpendicular direction across the two selected segments of the trench were automatically digitized. Developed algorithm of the semi-automated digitizing of the profiles enabled to visualize gradients of the slope steepness of the trench. The data were then modelled to show gradient variations in its two segments. The results of the comparative geomorphic analysis of northern and southern transects revealed variations in different parts of the trench. Presented research provided more quantitative insights into the structure and settings of the submarine landforms of the hadal trench that still remains a question for the marine geology. The research demonstrated the effectiveness of the GMT: a variety of modules, approaches and tools that can be used to produce high-quality mapping and graphics. The GMT listings are provided for repeatability.

Open access