Searcharxiv⌕ Search

arXiv subjects

Polina Lemenkova

Publications and source records attributed to Polina Lemenkova.

6 recordsLinked to original sources

Mapping topographic, geophysical and gravimetry data of Pakistan -- a contribution to geological understanding of Sulaiman Fold Belt and Muslim Bagh Ophiolite Complex

Along with the development of the scripting technology in cartography, such as the GMT and libraries of R programming language, geologic and geophysical mapping is being vigorously promoted, where the integration of the thematic data, such as GEBCO, EGM-2008 and geological raster and vector layers is one of the primary datasets that provides the high-resolution raw sources for cartographic visualization in the geologically complex regions like Pakistan. This study aims to integrate scripting methods of automated cartography, methods of applied geoinformatics for geomorphometric analysis and technical data processing (formatting, projecting, plotting), to provide a synthesis of the geological, geophysical and geomorphological maps of Pakistan they as new information supporting analysis of the geospatial variations of geology, geomorphology, tectonics and gravity fields with a special focus on the geologically remarkable region of Pakistan: Sulaiman Fold Belt and Muslim Bagh ophiolite complex. This study presents new 12 thematic maps, which are technically made using scripting approaches and open tools. All maps cover the region of Pakistan and they are made using open source tools: GMT, R and QGIS. A GMT and R based scripting mapping is applied for mapping Pakistan, and its algorithm steps are presented stepwise as code snippets. A system complex approach of the data integration and formats reshaping, data conversion and reformatting for a single project of the geology of Pakistan is designed and developed based on the combination of the programming and scripting techniques and with additional mapping, which integrates the geospatial datasets. Correlation between spatial phenomena of Earth's gravity, geologic evolution and tectonic movements were commented.

physics.geo-ph↗

Data Sharing, Distribution and Updating Using Social Coding Community Github and LaTaX Packages in Graduate Research

Current paper reports the advantages of the application of GitHub and LaTeX for the MSc thesis writing. The existing code-based program implemented in GitHub portal provides a great tool for scientists and students for data sharing and notification of the co-workers, tutors and supervisors involved in research about actual updates. It enables to connect collaborators to share around current results, release datasets and updates and more. Using standard command-line interface GitHub allows registered users to push repositories on the website. The availability of both public and private repositories enables to share current data updates with target audience: e.g. unpublished research work only for co-authors or supervisors, or vice versa. Therefore, there is a need in academic centres and universities to strongly popularize and increase the use of GitHub for student works. The case study is given on the graduate study: an MSc work written and maintained using open source GitHub service at the University of Twente, Faculty of Geo-Information Science and Earth Observation (Netherlands). It reports my successful experience of writing MSc thesis based on the effective combination of LaTeX and GitHub.

cs.CY↗

Urban-Rural Environmental Gradient in a Developing City: Testing ENVI GIS Functionality

The research performs urban ecosystem analysis supported by ENVI GIS by integrated studies on land cover types and geospatial modeling of Taipei city. The paper deals with the role of anthropogenic pressure on the structure of the landscape and change of land cover types. Methods included assessment of the impact from anthropogenic activities on the natural ecosystems, evaluation of the rate and scale of landscape dynamics using remote sensing data and GIS. The research aims to assist environmentalists and city planners to evaluate strategies for specific objectives of urban development in Taiwan, China.

cs.CY↗

Topology, homogeneity and scale factors for object detection: application of eCognition software for urban mapping using multispectral satellite image

The research scope of this paper is to apply spatial object based image analysis (OBIA) method for processing panchromatic multispectral image covering study area of Brussels for urban mapping. The aim is to map different land cover types and more specifically, built-up areas from the very high resolution (VHR) satellite image using OBIA approach. A case study covers urban landscapes in the eastern areas of the city of Brussels, Belgium. Technically, this research was performed in eCognition raster processing software demonstrating excellent results of image segmentation and classification. The tools embedded in eCognition enabled to perform image segmentation and objects classification processes in a semi-automated regime, which is useful for the city planning, spatial analysis and urban growth analysis. The combination of the OBIA method together with technical tools of the eCognition demonstrated applicability of this method for urban mapping in densely populated areas, e.g. in megapolis and capital cities. The methodology included multiresolution segmentation and classification of the created objects.

eess.IV↗

Factor Analysis by R Programming to Assess Variability Among Environmental Determinants of the Mariana Trench

The aim of this work is to identify main impact factors affecting variations in the geomorphology of the Mariana Trench which is the deepest place of the Earth, located in the west Pacific Ocean: steepness angle and structure of the sediment compression. The Mariana Trench presents a complex ecosystem with highly interconnected factors: geology (sediment thickness and tectonics including four plates that Mariana trench crosses: Philippine, Pacific, Mariana, Caroline), bathymetry (coordinates, slope angle, depth values in the observation points). To study such a complex system, an objective method combining various approaches (statistics, R, GIS, descriptive analysis and graphical plotting) was performed. Methodology of the research includes following clusters: R programming language for writing codes, statistical analysis, mathematical algorithms for data processing, analysis and visualizing diagrams, GIS for digitizing bathymetric profiles and spatial analysis. The statistical analysis of the data taken from the bathymetric profiles was applied to environmental factors, i.e. coordinates, depths, geological properties sediment thickness, slope angles, etc. Finally, factor analysis was performed by R libraries to analyze impact factors of the Mariana Trench ecosystem. Euler-Venn logical diagrams highlighted similarities between four tectonic plates and environmental factors. The results revealed distinct correlations between the environmental factors (sediment thickness, slope steepness, depth values by observation points, geographic location of the profiles) affecting Mariana Trench morphology. The research demonstrated that coding on R language provides a powerful and highly effective statistical tools, mathematical algorithms of factor analysis to study ocean trench formation.

physics.geo-ph↗

R scripting libraries for comparative analysis of the correlation methods to identify factors affecting Mariana Trench formation

Mariana trench is the deepest place on the Earth. It crosses four tectonic plates of the Pacific Ocean: Mariana, Caroline, Pacific and Philippine. The formation of the trench is caused by the complex interconnection of various environmental factors. The aim of this study was to describe and characterize various impact factors affecting formation of the Mariana trench geomorphology and continental margin environments using R programming language and mathematical algorithms of correlation methods written on R code. To record the system of geological, tectonic, geographic, oceanological and bathymetric features affecting Mariana trench , a combination of statistical methods, GIS and R programming codes were applied. The questions answered are as follows: which factors are the most influencing for the Mariana trench morphology, and to what extend do they affect its development? Is sedimental thickness of the ocean trench basement more important factors for the trench formation comparing to the steepness slope angle and aspect degree? Three methods of computing were tested: Pearson correlation, Spearman correlation, Kendall correlation, numerical correlogram, correlation matrix and cross-correlatios to analyze environmental impact factors. The correlogram matrices are computed and visualized by R scripting libraries. Complex usage of programming tools, mathematical statistics and geospatial analysis enabled to get a differentiated understandings of the hadal environments of the Mariana trench. The results revealed following three types of factors having the highest score: geometric (tg° slope angle), geologic (sedimental thickness) and tectonic structure. The results furthermore indicated that tectonic plates, sedimental thickness of the trench basement and igneous volcanic areas causing earthquakes play the most essential role in the geomorphology of the trench.

physics.geo-ph↗