National Repository of Grey Literature 19 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Evaluation of forest vegetation based on time series of remote sensing data
Laštovička, Josef ; Štych, Přemysl (advisor) ; Brom, Jakub (referee) ; Bucha, Tomáš (referee)
Příloha k disertační práci: Abstrakt v AJ (Mgr. Josef Laštovička) Abstract This dissertation thesis deals with the study of forest ecosystems in the central Europe with the time series of multispectral optical satellite data. These forest ecosystems have been influenced by biotic and abiotic disturbances for the last decade. The time series of the satellite data with high spatial resolution allow the detection and analysis of forest disturbances. This thesis is mainly focused primally on free available Landsat and Sentinel-2 data, these two data types were compared. From methods, the difference time series analyses / algorithms were used. The whole thesis can be divided into two main parts. The first one analyses usability of classifiers for detection of forest ecosystems with per-pixel and sub-pixel methods. Specifically, the Neural Network, the Support Vector Machine and the Maximum Likelihood per-pixel classifiers were used and compared for different types of data (for data with high spatial resolution - Landsat or Sentinel-2; very high spatial resolution - WorldView-2) and for classification of protected forest areas. The Support Vector Machine were selected as the most suitable method for forest classifications (with most accurate outputs) from the list of selected per-pixel classifiers. Also, Spectral...
Effects of urbanization on the landscape of a Modern City in Ghana: A case study of sunyani
Boateng, K. A. ; Mensah, Caleb ; Agyei, Thomas ; Švik, Marian
Changes in land use through urbanization and agriculture are the key anthropogenic effects of climate change. Thus, the preservation of natural environment of urban areas is essential for conserving water and soil, while still adjusting the microclimatic variables (temperature, precipitation, relative humidity, etc.) and stabilizing the natural ecological system from destruction. It has been observed that most parts of city's green vegetation have been lost due to housing developments and commercial activities. This study was carried out to assess the effect of the change in land use on a modern city like Sunyani, by observing the significant changes in vegetation cover from LANDSAT TM imagery over a 31-year period (1986 – 2017). From the study, there was significant decline of vegetation cover from 1986 to 1999, and no significant change from 1999 to 2017. There were also significant changes in the built-up areas from 1986 to 1999 and no significant change from 1999 to 2017. Adoption of sustainable and environmentally friendly technologies that maintain open green vegetation is recommended for future city planning.
Using satellite data of the Landsat program for environmental research with a case study focused on assessment of vegetation indexes in the area of Sokolovsko
Mosoriaková, Gabriela ; Matějíček, Luboš (advisor) ; Rojík, Petr (referee)
This thesis focuses on the use of remote sensing imagery and satellite image Landsat in the research of land during the revitalization, re-cultivation, and re-naturalization process. The area of the case study is the Sokolov dump. The dump is a typical long-term surface mining area and is a perfect model for the revitalization process. The thesis compares satellite imagery from the LandSat company during a period of time. The pictures are selected so that the land is not obscured by weather patterns and cloud cover. These pictures allow the evaluation of the Vegetation Index (NDVI, EVI, SAVI and MSAVI). Two areas are compared with different types of revitalization. The first is the natural process and the second is a controlled environment. The expected results should show that that the terrain data from the remote sensing images correspond to the actual land survey. The images are processed using ArcGIS and then evaluated in MatLab.
Effects of urbanization on the landscape of a Modern City in Ghana: A case study of sunyani
Boateng, K. A. ; Mensah, Caleb ; Agyei, Thomas ; Švik, Marian
According to the fifth assessment report of the Intergovernmental Panel on Climate Change, changes in land use through urbanization and agriculture are the key anthropogenic effects of climate change. Thus, the preservation of natural environment of urban areas is essential for conserving water and soil, while still adjusting the microclimatic variables (temperature, precipitation, relative humidity, etc.) and stabilizing the natural ecological system from destruction. It has been observed that most parts of city's green vegetation have been lost due to housing developments and commercial activities. This study was carried out to assess the effect of the change in land use on a modern city like Sunyani, by observing the significant changes in vegetation cover from LANDSAT TM imagery over a 31-year period (1986-2017). From the study, there was significant decline of vegetation cover from 1986 to 1999, and no significant change from 1999 to 2017. There were also significant changes in the built-up areas from 1986 to 1999 and no significant change from 1999 to 2017. Adoption of sustainable and environmentally friendly technologies that maintain open green vegetation is recommended for future city planning.
Urban vegetation - temporal analysis of urban vegetation impact on local climate using remote sensing
PAVLÍČKOVÁ, Lenka
The urban heat island (UHI) is a phenomenon of noticeably higher temperatures in the cities as compared to their respective surrounding areas. This thesis aims at characterizing the influence of city expansion to the urban heat island phenomenon. The study is carried out in a city of Caceres in the Spanish province of the same name. A model input data is obtained with Landsat multispectral images. The analysis of satellite images shows that functional vegetation cover and water surfaces help in mitigating urban heat island effect. However, the Caceres city expansion does not influence the urban heat island intensity. A possible explanation for it is as the city expanded the ratio of vegetation to dry land remains constant in time.
Impact of different types of land cover on physical parameters of landscape surface
KUNTZMAN, Jan
The aim of the thesis was understanding the energy fluxes in different types of land cover. The area of interest is located in Novohradské hory in the basins of Váčkový and Pasecký potok. On a relatively small area there are five different types of land cover to be found (field, forest, permanent grassland, wetland and built-up area). For each of the types of land cover three properties of the surface were calculated: amount of vegetation on the surface, wetness of the surface and surface temperature. Moreover, soil heat flux, latent heat flux and sensible heat flux were established therefore surface thermal balance was evaluated. Results were statistically processed with boxplot diagrams as an outcome. The results support the hypothesis of vegetation having a positive effect on microclimate conditions. Especially the permanent cultures (wetlands, permanent grassland, forest) demonstrated much larger microclimatic stability and balance as well as capability of keeping moist. Thanks to insufficient intensity of vaporization (due to lack of water), built-up areas showed higher surface temperatures and sensible heat flux at most of the cases. Vegetation is capable of holding water and redistributing it in an environment via evapotranspiration. Thus, solar energy is stored inside of the water vapour which condensates on cool objects releasing the energy spent during the vaporization process. Water moves in the landscape through the local-scale water cycle stabilizing the microclimate.
Statistical analyses of Land Surface Temperature in Local Climate Zones: Case study of Brno and Prague (Czech Republic)
Geletič, Jan ; Dobrovolný, Petr ; Lehnert, M.
The classification of "local climate zones" (LCZs) emerged in urban climatology to standardize description of urban climate research sites. One of the goals of classification was to get beyond urban-rural dichotomy which enabled to study urban air temperature field in more detail. Based on empirical and modelling work LCZ have proven effective in examining intra-urban air temperature differences, however a robust examination of intra-urban land surface temperatures using the LCZ framework remains elusive. In this study a GIS-based method is used for LCZ delimitation in Prague and Brno (Czech Republic), while land surface temperatures (LSTs) derived from LANDSAT and ASTER satellite data are employed for exploring the extent to which LCZ classes discriminate with respect to LSTs. Results indicate that LCZs demonstrate the features typical of LST variability, and thus typical surface temperatures differ significantly among most LCZs. ANOVA and subsequent multiple comparison tests demonstrated that significant temperature differences between the various LCZs prevail in both cities (89.3% and 91.6% significant LST differences for Brno and Prague respectively). In general, LCZ 8 (large low-rise buildings), LCZ 10 (heavy industry) and LCZ D (low plants) are well-distinguishable, while LCZ 2 (compact midrise), LCZ 4 (open high-rise), and LCZ 9 (sparsely built-up) are less distinguishable in terms of their LST. In most of the scenes LCZ 10 (heavy industry), LCZ 2 (mid-rise buildings) and LCZ 3 (low-rise building) are the warmest and LCZ G (water bodies) and LCZ A (dense forest) are the coolest zones in term of their LST. Further studies are needed to account for observational errors (such as seasons differences or thermal anisotropy) on LCZ LST patterns.
Changes of land cover above the tree line in Krkonoše National Park based on Landsat data
Vyvialová, Linda ; Červená, Lucie (advisor) ; Suchá, Renáta (referee)
CHANGES OF LAND COVER ABOVE THE TREE LINE IN KRKONOŠE NATIONAL PARK BASED ON LANDSAT DATA Abstract This study evaluates land cover changes in the area above the tree line in Krkonoše Mts. National Park. The stress is put on the changes of Pinus mugo shrub. Two methods of change detection based on Landsat data in four time horizons from the eighties up to now were tested (years 1984, 1992, 2002 and 2013). The first method was classification of scenes with the Maximum Likelihood Classifier individually and evaluation of changes based on their overlay. Overall accuracies from the oldest scene were 86,04 %, 88,44 %, 86,91 % and 86,43 %. The second method evaluates detection of change above one dataset that consists of scenes for all the time horizons. Overall accuracies were from the oldest 86.63 %, 88.64 % and 86.11 %. The second method was more appropriate for this study of land cover changes. On the map results there can be seen thinning of Pinus mugo scrub (between the years 2002 and 2013, 1984 and 1992) as well as its natural thickening and spreading. Key words KRNAP, tundra, land cover, change detection, Landsat
MONITORING OF DEFOLIATION USING REMOTE SENSING TECHNIQUES
Prokopec, Karel ; Kolář, Jan (advisor) ; Fabiánek, Petr (referee)
The aim of this diploma thesis is a proposal of a methodology used for an assessment of the measure of defoliation based on the multispectral satellite images from missions Landsat and Sentinel-2. The first part of the thesis is dedicated to the introduction of the problematics of remote sensing using multispectral sensors and the basics of research into forest vegetation. Following on this part, there is a chapter considering possibilities of monitoring defoliation using resources of remote sensing, and the closely connected problematics of the health condition of forest vegetation. After that comes a description of the used data (the satellite images and the data of ground investigation by VÚLHM) and logically compounded process of transformation of the data from satellite images on the levels of defoliation. Outcomes of the thesis include analysis of the ability of single spectral bands and vegetation indices to predict defoliation of Norway spurce (Picea abeis) and Scots pine (Pius sylvestris) vegetation. The assessment of the measure of defoliation is demonstrated on single band in near-infrared region with used of linear regression model.
Detection of Equilibrium Line Altitude (ELA) Changes from Remote Sensing Data; Case Study from the Cordillera Blanca, Peru
Paraj, Zsolt ; Potůčková, Markéta (advisor) ; Kropáček, Jan (referee)
The aim of this diploma thesis is to monitor glacier change in the Cordillera Blanca in the period from 1987 to 2014. This diploma thesis focuses on three mountains and eleven glaciers in the northern part of the Cordillera Blanca. The input data consist of 29 Landsat scenes (Landsat 4,5,7 and 8) and the ASTER global digital elevation model version 2. Semi-automatic classification algorithm is created based on threshold values detected by spectral analyses of selected land cover types in the Cordillera Blanca. Additionally, the mean snowline (equilibrium line) altitude change is computed for all of the three mountains and eleven glaciers. Besides, glacier change depending on slope and aspect is evaluated. The results of this diploma thesis are presented in maps, tables and charts. The results of the classification are compared with the GLIMS Glacier Database and the field measurements provided by Adam Emmer, MSc. Finally, the advantages and disadvantages of the new Landsat 8 satellite sensor are discussed. Key words: Remote sensing, Landsat, classification, ice and snow detection, ELA, Cordillera Blanca

National Repository of Grey Literature : 19 records found   1 - 10next  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.