Wyniki wyszukiwania - BazTech

1

The analysis of spatial and temporal changes of land cover and land use in the reclaimed areas with the application of airborne orthophotomaps and LANDSAT images

Szostak M., Wężyk P., Hawryło P., Pietrzykowski M.

Geodesy and Cartography

|

2015

|

Vol. 64, no. 1

75--86

EN

The aim of this study was to investigate the possible use of geoinformatics tools and generally available geodata for mapping land cover/use on the reclaimed areas. The choice of subject was dictated by the growing number of such areas and the related problem of their restoration. Modern technology, including GIS, photogrammetry and remote sensing are relevant in assessing the reclamation effects and monitoring of changes taking place on such sites. The LULC classes mapping, supported with thorough knowledge of the operator, is useful tool for the proper reclamation process evaluation. The study was performed for two post-mine sites: reclaimed external spoil heap of the sulfur mine Machów and areas after exploitation of sulfur mine Jeziórko, which are located in the Tarnobrzeski district. The research materials consisted of aerial orthophotos, which were the basis of on-screen vectorization; LANDSAT satellite images, which were used in the pixel and object based classification; and the CORINE Land Cover database as a general reference to the global maps of land cover and land use.

2

Mapy podstawowych form pokrycia i użytkowania terenu zlewni Raby powyżej Zbiornika Dobczyckiego - porównanie dokładności klasyfikacji pikselowej i obiektowej obrazów LANDSAT TM

Badurska M., Drzewiecki W., Tokarczyk P.

Teledetekcja Środowiska

|

2009

|

T. 42

15--21

EN

The research presented in the paper has been aimed at mapping the basic types of land-use in the upper Raba watershed (south Poland). The maps have been prepared for a study of the influence of land-use changes within the watershed on the sediment yields introduced into the reservoir. Because the erosion models used for sediment yields prediction need only to identify the main land-use / land cover classes (arable land, meadows and pastures, forests, waters, developed areas), the maps have been based on classification of middle-resolution satellite images (Landsat TM). In the research the results of traditional pixel-based classification were compared to the ones obtained in the object based approach. Six different Landsat TM images were classified. The methodology of both classification approaches have been described in the paper. The accuracy assessment of the classification results was based on their comparison with the land use types defined by the photo interpretation of colour composite images. The assessment was done by two operators. Each of them used different set of two hundred and fifty randomly generated sample points. In most cases the pixel-based approach resulted in higher overall accuracy. However, if overall accuracy confidence intervals are taken into consideration, none of the methods can be definitely recognised as a better one.

3

Porównanie klasyfikacji obiektowej z tradycyjną klasyfikacją pikselową z punktu widzenia automatyzacji procesu tworzenia bazy danych o pokryciu i użytkowaniu terenu

Lewiński S.

Roczniki Geomatyki

|

2007

|

T. 5, z. 1

63-70

EN

The capabilities of land cover and land use classes identification using object-oriented classification and traditional, so-called pixel-based classification are compared in the paper. The comparison is based on the Landsat satellite image showing a study area of over 423 km2, located within the borders of the Commune of Legionowo (near Warsaw). The results of both classifications were generalised, using a working unit of 1 ha for built-up areas and water and 4 ha for the remaining classes. Object-oriented classification was performed within eCognition software environment. The applied tools of object-oriented classification enabled identification of 18 classes. Subsequent generalisation caused changes only to the area constituting 1.1% of the entire study area. Classification accuracy assessment using the method of visual interpretation and creation of the final land cover and land use database was the final stage of works. The accuracy for the entire study area reached over 94%. Traditional pixel-based classification was performed using so-called hybrid classification, which involves performing supervised classification and then unsupervised classification for unclassified pixels. The pixel-based approach enabled identification of only 8 classes. In the process of generalisation, based on the same principles as in the case of object-oriented classification, 26% of the area of the analysed image was changed. The accuracy of pixel-based classification, assessed by comparing the post-generalisation image to the database obtained after the visual verification of object-oriented classification, reached 72% and 61%, according to the comparison method applied. The results of comparing these two methods of classification prove a significant advantage of objectoriented classification over traditional pixel-based classification. The tools of object-oriented classification enabled identification of twice as many number of classes and a high level of accuracy of the classification process. Moreover, object-oriented classification enables proper generalisation, necessary for creating a land use and land cover database with a defined level of spatial resolution of class recognition.