For the last 20 years researchers have tried to create new approaches of managing urban ecosystem by using remote sensing methods. The authors estimated the normalized vegetation index (NDVI) and moisture index (NDMI) indices of Kyiv and propose an approach which can be used for estimation vegetation of other cities. The aim of the study was to assess the indicators of NDVI and NDMI in Kyiv for the last 5 years. The authors consider the NDVI index as an important ecostabilizing component of the urban ecosystem, as well as an indicator of the well-being citizens in a modern city. The study used space images of the Sentinel-2 satellite system with resolution of 10×10 m and 10×20 m. The images were decrypted using the Sentinel Hub platform which updates the data-base daily. The paper presents the results of correlation analysis using Statistica-6.0 software and demonstrate the close relationship (r = 0.73, r2 = 0.55) between NDVI and NDMI. Thus, the statistical results of the study confirm a strong correlation between photosynthetic activity of plants and indicators of their water content by satellite imagery which allows using modern satellite technologies to assess the functional state of the urban vegetation. The changes in the length of active vegetative growth period were identified by NDVI and NDMI. The results of the research expand the directions of the methods of monitoring the condition of the urban vegetation cover in the aspect of applied landscape research.
The object of the study is the processing of space images on the territory of the Carpathian territory in the Lviv region, obtained from the Landsat-8 satellite. The work aims to determine the area of deforestation in the Carpathian territory of the Lviv region from different time-space images obtained from the Landsat-8 satellite. Methods of cartography, photogrammetry, aerospace remote sensing of the Earth and GIS technology were used in the experimental research. The work was performed in Erdas Imagine software using the unsupervised image classification module and the DeltaCue difference detection module. The results of the work are classified as three images of Landsat-8 on the territory of the Carpathian territory in the Lviv region. The areas of forest cover for each of them for the period of 2016-2018 have been determined. During the three years, the area of forests has decreased by 14 hectares. Our proposed workflow includes six stages: analysis of input data, band composition of space images on the research territory, implementation of unsupervised classification in Erdas Imagine software and selection of forest class and determination of implementing this workflow, the vector layers of the forest cover of the Carpathians in the Lviv region for 2016, 2017, 2018 were obtained, and on their basis, the corresponding areas were calculated and compared.
The paper discusses the problem of using QuickBird space images to provide land cadastral surveys and regulations regarding the protection and rational use of land under specific conditions: hard-to-rich areas, limited funds, time and staff for the inspection and monitoring of large territories. Legal, technical and technological questions concerning the use of QuickBird images and geoinformation technologies for the specified purposes are analysed in the work.
The paper analyses the causes of riverbeds shifts and meandering of Dniester. Among such reasons are mostly climatic, geographical and anthropogenic factors, such as frequent floods semi-stable rocks and soils, deforestation and removal of gravel and sand material from the river bed. The research is carried out on the lowland of the Dniester along the 100 km section over the 100 years period. Topographic maps (1910, 1923, 1976 years), and satellite images from Landsat 5 (1986) Landsat 7 (2000) Sentinel (2017) and special soil maps was taken as initial information. The Dniester meandering research shows significant correlation in horizontal riverbed movements for the periods from 1910 till 1986 and from 1984 till 2017. Correlation rate variate within the limits 0.97 – 0.99 respectively that corresponds to the almost full dependence in the riverbed displacement configuration. Beside that the maximum horizontal deviations can reached up to 800 meters. In addition, it was revealed that sediment processes caused significant increase in the area of the river islands from 1910 to 1976 by 2.4 times, and from 1976 to 2017 the island areas somewhat reduced. Nearly the largest island River channel is divided into two branches. Sinuosity coefficient is 2.3 over the test site. The analysis of soil maps shows prevailing bleached soils and loamy on alluvial deposits soils in areas with highest sinuosity coefficient.
PL
Za główne przyczyny przemieszczenia się i meandrowania koryta rzek uznaje się zjawiska klimatyczne, a także czynniki geograficzne i antropogeniczne. Częste powodzie, określone rodzaje skał i gruntów, wylesienia i wymywanie żwiru i piasku z łożyska powodują przemieszczenie rzeki. Prezentowane badania przemieszczeń dotyczą równinnej części rzeki Dniestr. Analiza została przeprowadzona na odcinku rzeki długości około 100 km i dotyczy okresu minionych 100 lat. Do badań wykorzystano mapy topograficzne z lat 1910, 1923, 1976 i zdjęcia satelitarne z satelity Landsat 5 (1986), Landsat 7 (2000) i Sentinel (2017), a także mapy gruntów. Z badań meandrowania rzeki Dniestr w okresach 1910-1986 i 1984-2017 określono związki korelacyjne między przemieszczeniami sytuacyjnymi, które wyrażone w formie współczynnika korelacji wynoszą odpowiednio 0.99 i 0.97, co świadczy o prawie całkowitym związku kształtów łożysk. Jednocześnie wyjaśniono że maksymalne przemieszczenia łożyska rzeki na odcinkach 1 i 2 wynoszą blisko 800 m, a na odcinku 5 do 100 m. Wyjaśniono, że zwiększenie niesionych osadów spowodowało w latach od 1910 do 1976 znaczny wzrost powierzchni wysp (około 2,4 razy), a w latach od 1976 do 2017 powierzchnia wysp zmniejszyła się, jednak w miejscu największej wyspy koryto podzieliło się na dwa rękawy. Ogółem krętość koryta na badanym fragmencie wynosi 2.3, co świadczy o tym że koryto jest meandrujące. Analiza mapy gruntów w miejscach maksymalnego meandrowania wskazuje, że głównymi typami gruntów są gleby łąkowe bielicowe i oglejone na złożach naniesionych.
The paper presents a hybrid classification method based on the determination of the optimal number of classes according to uncontrolled classification followed by image processing techniques of controlled classification. A criterion for determining the optimal number of classes is proposed based on the definition of averaged values differences of average spectral brightness among the classes. Space images from satellites Ikonos (2002, 2007) and QuickBird (2010) were used to study different time cuttings in the forests of the Carpathian region. A significant amount of ground observation was held for getting test information. A Hybrid Classification Method is used for different time cuttings by QuickBird satellite images and implemented in a software environment of ERDAS Imagine. In order to obtain acreage of cuttings made for the period of 2002-2007 and 2007-2010, a comparative analysis of cuttings is introduced in these time intervals and their area is determined on the basis of the digital images of polygons in the ArcGIS software environment.
Space information, or information obtained by means of space remote sensing, is widely and effectively used by many countries to solve a lot of scientific, technical and applied problems. Most manufacturers of space remote sensing systems declared the high resolution values of their systems. However, these values are computed theoretically, without considering the various factors affected them. To determine the real resolution of the system, we have considered mathematical modeling which describes the influence of different factors on the satellite images resolution. Some of these factors are: atmosphere turbulence, image shift, residual defocusing, and diffraction. One of the most important characteristic of the images resolution is the modulation transfer function (MTF) which allows the estimation of different factors affected on the image resolution. The modulation transfer function (MTF) is a fundamental tool for assessing the performance of imaging systems. Various authors [Zhang et al. 2012, Hwang et al. 2008, Ryan et al. 2003] investigate diferent MTF assessment methods of high resolution satellite images: a slant-edge method, a knife-edge method, a sine wave method and a grill pattern. We propose a generalized approach for MTF assessment based on theoretical assumptions which allows to determine the inluence of diferent factors. A comparative analysis of the modulation transfer function(s) for different space imaging systems shows that the image resolution depends mainly on the atmosphere turbulence and size of a sensor element. Additionally, we established that atmospheric turbulence significantly reduces the transmitting possibility of images. The parameters which describe the influence of turbu¬lence required additional studies. The main goal of our researches is to show that real spatial image(s) resolution is much "inferior" than the value provided by the manufacturers of space remote sensing systems.
Two methods of determining changes of objects (structures) using remote sensing data obtained in different times are considered in this article. The comparison of the percentage of destroyed buildings as a consequence of the earthquake in L'Aquila city (Italy) was implemented. For comparison two ways of data collection were used: obtaining data by the digitalization of objects before and after the disaster (using MapInfo software) and by automatic image classification using a special module Delta Cue (Erdas software).
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