Vrtače so najbolj tipična površinska oblika krasa zmernih geografskih širin. Na podlagi obdelave digitalnega modela višin z orodji GIS smo proučili gostoto vrtač in njihove morfometrične lastnosti ...glede na naklon pobočij. Proučena so bila tri območja s primerljivimi reliefnimi, geološkimi, podnebnimi in hidrološkimi značilnostmi na Hrušici, Snežniku ter Slavniškem pogorju. Ugotovili smo, da se gostota in večina izbranih morfometričnih lastnosti spreminjajo sorazmerno z naklonom površja.
Hitra urbanizacija ima številne negativne vplive na okolje in zdravje ljudi ter pomembno prispeva h globalnemu segrevanju. Eden izmed teh vplivov so tudi mestni toplotni otoki, ki jih povzroca ...clovekova dejavnost in so opredeljeni kot temperaturne razlike med mestnimi in okoliškimi obmocji. Zaradi hitre urbanizacije v zadnjih desetletjih se Skopje spoprijema z izjemno mocnimi ucinki mestnih toplotnih otokov. Za proucevanje vloge pozidanih in zelenih površin pri nastanku površinskega mestnega toplotnega otoka je avtorica uporabila satelitske podatke Landsat ETM+, na podlagi katerih je analizirala temperaturo tal, in posnetke satelita Planet Scope DOVE visoke locljivosti, na podlagi katerih je analizirala pozidane in zelene površine. Za geostatisticne analize je uporabila 17 nakljucno izbranih podobmocij v Skopju. Izsledki raziskave kažejo pomembno povezavo med mestnim toplotnim otokom in pozidanimi površinami ter mocno povezavo med zelenimi površinami in obmocji, na katerih ni mestnega toplotnega otoka, kar kaže, da se lahko ucinek mestnih toplotnih otokov pomembno zmanjša z dodatnimi zelenimi površinami. Eden izmed pomembnih izsledkov raziskave je, da idealno razmerje med deležem pozidanih in zelenih površin, pri katerem je ucinek mestnega toplotnega otoka šibek, v nekaterih primerih pa ga celo ni, znaša 40 : 60. Nadaljnje raziskave bi se morale osredotocati še na druge dejavnike, ki lahko vplivajo na nastanek mestnega toplotnega otoka.
This guide provides an insight into a range of visualization techniques for high-resolution digital elevation models (DEMs). It is provided in the context of investigation and interpretation of ...various types of historical and modern, cultural and natural small-scale relief features and landscape structures. It also provides concise guidance for selecting the best techniques when looking at a specific type of landscape and/or looking for particular kinds of forms.The three main sections – descriptions of visualization techniques, guidance for selection of the techniques, and visualization tools – accompany examples of visualizations, exemplar archaeological and geomorphological case studies, a glossary of terms, and a list of references and recommendations for further reading. The structure facilitates people of different academic background and level of expertise to understand different visualizations, how to read them, how to manipulate the settings in a calculation, and choose the best suited for the purpose of the intended investigation.A smaller amount of books is also available in hardcover (ISBN 978-961-05-0011-7, 24 EUR).
V članku analiziramo metodo izgradnje digitalnega modela reliefa iz podatkov lidar na testnih primerih z območja Slovenije. Ker obe metodi temeljita na konceptih matematične morfologije, podrobneje ...predstavimo eno, medtem ko uvodoma podamo splošen pregled del na obravnavanem območju. Rezultati pokažejo, da se z obema metodama pravilno določi teren v več kot 90 odstotkih, in sta zato obe primerni za uporabo tudi na geografsko tako razgibanem območju, kot je Slovenija. Čeprav je na ravninskih območjih njuna natančnost primerljiva, opisana metoda omogoča natančnejšo izgradnjo digitalnega modela reliefa predvsem na zahtevnejših, goratih območjih z relativno strmimi in spremenljivimi nakloni ter na območjih s terasami. Tudi v teh primerih povprečna absolutna višinska napaka ni večja od 15 centimetrov ; This paper reviews two methods for digital terrain model generation from LiDAR data in test cases in Slovenia; both methods are based on concepts of mathematical morphology. A general overview of methods is given in the introduction, one of which is presented in more detail. The results show that both methods are able to correctly extract terrain points in more than 90% of the cases and are, therefore, suitable for usage even for such geographically diverse regions as Slovenia. Although the accuracy of both methods is comparable in cases of flat areas, the described method performs significantly better in problematic cases, such as hilly areas with relatively steep variable slopes, and terrains containing terraces. Even in these cases, the average absolute height error is not higher than 15 cm.
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Remote sensing has developed various methods and technologies for contactless and cost-effective mapping of large area land cover/land use maps and other thematic maps. The key factor for the ...availability and reliability of these maps for use in Earth sciences is the development of effective procedures for satellite data analysis and classification. The most appropriate approach for classifying low and medium resolution satellite images (pixel size is coarser than, or at best similar to, the size of geographical objects) is pixel-based classification in which an individual pixel is classified into the closest class based on its spectral similarity. With increasing spatial resolution, pixel-based classification methods became less effective, since the relationship between the pixel size and the dimension of the observed objects on the Earth's surface has changed significantly. Therefore object-oriented classification has become increasingly popular over the past decade. This combines segmentation (which is a fundamental phase of the approach) and contextual classification. Segmentation divides the image into homogeneous pixel groups (segments), which are -during the semantic classification process - arranged into classes based on their spectral, geometric, textural and other features during. The intent of this paper is to present the theoretical argumentation and methodology of object-based image analysis of remote sensing data, provide an overview of the field and point out certain restrictions as regards the current operational solutions.
This article presents a review and comparison of the detection capability of water facilities or water surfaces with different systems of remote sensing: optical and radar satellite sensors, as well ...as optical sensors on aircraft. The capabilities of water detection are estimatedfrom several aspects: differences in the spatial and spectral resolution of imagery, the complexity of imagery pre-processing requirements, and the method of analysis and interpretation feasibilities for the type and purpose of mapping. Particular attention is paid to evaluating the applicability of remote sensing data in light of the detection efficiency of water areas in heterogeneously structured environments.
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Remote sensing has developed various methods and technologies for contactless and cost-effective mapping of large area land cover/land use maps and other thematic maps. The key factor for the ...availability and reliability of these maps for use in Earth sciences is the development of effective procedures for satellite data analysis and classification. The most appropriate approach for classifying low and medium resolution satellite images (pixel size is coarser than, or at best similar to, the size of geographical objects) is pixel-based classification in which an individual pixel is classified into the closest class based on its spectral similarity. With increasing spatial resolution, pixel-based classification methods became less effective, since the relationship between the pixel size and the dimension of the observed objects on the Earth's surface has changed significantly. Therefore object-oriented classification has become increasingly popular over the past decade. This combines segmentation (which is a fundamental phase of the approach) and contextual classification. Segmentation divides the image into homogeneous pixel groups (segments), which are - during the semantic classification process - arranged into classes based on their spectral, geometric, textural and other features during. The intent of this paper is to present the theoretical argumentation and methodology of object-based image analysis of remote sensing data, provide an overview of the field and point out certain restrictions as regards the current operational solutions.
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Daljinsko zaznavanje v termičnem infrardečem spektru je sodobno orodje, ki nam omogoča opazovanje aktivnih ognjenikov. Z njim lahko zaznamo manjše toplotne anomalije, kot so vroči izviri ali ...fumarole,pa tudi večja telesa, kot so tokovi ali jezera lave. Vse anomalije imajo ne glede na temperaturo običajno manjšo površino od prostorske ločljivosti senzorjev (od 30 do 4000 m), ki so primerni za njihovo opazovanje. Da bi lahko anomalijo kljub temu zaznali in določilinjene fizikalne parametre, moramo uporabiti podatke iz več kanalov v ustreznem spektru. Toplotno anomalijo najbolj robustno opišemo s toplotnim tokom. Za razumevanje aktivnosti ognjenika moramo spremljatirazvoj časovne vrste toplotnega toka. Ker so satelitski podatki podvrženi vplivom atmosfere, reliefa, itd., je v časovni vrsti vedno prisoten šum. Kot primer smo prikazali zmanjšanje šuma s kalmanovim filtrom, s katerim smo obdelali izbruh Etne jeseni 2002. : Thermal remote sensing is a valuable tool for monitoring active volcanoes. One can use it to detect smaller thermal anomalies, such as hot springs or fumaroles. It is successful also by detecting largeranomalies, such as lava flows or lava lakes. All these anomalies usually cover only a small area comparing to the ground sample distance of the sensors that are appropriate for their monitoring. This makes detecting and characterizing the thermal anomaly a difficult task that is solved by using more data from severalbands covering the appropriate spectra. The most robust parameter to characterize a thermal anomaly is radiative heat flux. We need to analyse its time series in order to understand the volcano activity. Satellite data are influenced by the atmosphere, terrain, etc.Therefore, the time series always contains some noise. For a case study we applied Kalman filter to minimise the noise in the case study of Etna eruption in autumn 2002.
This article aims to present the change detection methodology as experienced in the use of optical remote sensing imagery (Landsat) and its pitfalls when multitemporal analyses are performed with ...pixel-based (raster algebra) techniques. The existing methodologyrecommends fundamental data preparation (geometric, radiometric, topographic corrections) and offers numerous change detection techniques. Regardless of the carefully performed preparationscertain noise remains, which can drastically weight the imagery comparisons. This noise behaves as a detected change and could have such a false effect on the identified change pattern (i.e. false, non-intrinsic changes) that the quantitative evaluation might fail.Since this noise originates from the pre-processing algorithms as well as the natural and technological conditions during data acquisition it can not be completely removed by data corrections. A multiresolution change detection approach is therefore proposed. Taking into account the neighbourhood and change information from joining different spatial scales, the multi-resolution approach effectively reduces the amount of false changes. In the discussion the remote sensing imagery for surface change detection is evaluated.
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