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  • Author: Katarzyna Osińska-Skotak x
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Marzena Wicht and Katarzyna Osińska-Skotak

Abstract

This paper presents the results of the urban indicators analysis conducted within Warsaw’s ventilation corridors from 1992 to 2011. The literature review shows that the Floor Area Ratio (FAR) index is one of the best indicators to detect urban development; therefore, this was the core of the analysis. Three periods were analysed (1992 – 2002 – 2011), as such a long time-span allows the assumption that change will be visible. The ventilation corridors were divided into 500 m and 100 m grids and the FAR index was calculated for each cell. The results highlight alarming changes within some of the corridors, indicating areas that are crucial to sufficient air flow in Warsaw.

Open access

Beata Weintrit, Katarzyna Osińska-Skotak and Magdalena Pilarska

Abstract

This article presents an extensive feasibility study of the use of optical satellite data for flood risk monitoring. The article presents a review of existing and archival satellite systems. The capabilities and restrictions of using earth observation data are presented, in relation to the identified threat and taking into account the size, genesis and cause. The initial results of the studies demonstrate the potential of very high and highresolution satellite imagery for the operational detection of damage and risk areas. In the presented approach, two analyses were conducted: bare soil detection and water range detection, based on different radiometric indices. As a result of the conducted research, the best results in bare soil detection were obtained using the MSAVI and NDVI indices. The most effective at delimiting water was the NDVI index. The automatization of satellite data processing from different satellite systems gives opportunities for hydrological services and crisis management professionals to access accurate and up-to-date information about the condition of levees for the early detection of flood risk.

Open access

Janina Zaczek-Peplinska and Katarzyna Osińska-Skotak

Abstract

Dynamically developing terrestrial laser scanning technology (TLS)provides modern surveying tools, that is, scanning total stations and laser scanners. Owing to these instruments, periodic control surveys of concrete dams were performed as a part of geodetic monitoring yield point models characterised by quasicontinuity. Using the results of such measurements as a base, one can carry out a number of geometric analyses as well as acquire information for detailed analytical and calculative considerations.

The scanner, similar to total station, by determining distances and angles, identifies spatial coordinates (X, Y, Z) of the surveyed points. Registration of the reflected laser beam’s intensity value (Intensity) emitted by the scanner provides additional information on the surveyed object. Owing to high working speed and the large amount of the collected data, the scanners became an indispensable tool for geodesists.

The article assesses the possibility of application of terrestrial laser scanning in surveying changes in the surface of a concrete dam based on the experimental measurements. The condition of the dam’s downstream concrete wall was evaluated. The evaluation included changes in the surface’s roughness, cracks, seepage points, erosion caused by plant overgrowth and the degressive durability parameter of the used material (concrete).

The article presents an example of the application of the results of a laser scan in the assessment of the condition of a water dam’s external concrete surfaces. The results of experimental measurements were analysed – the results of a scan of the downstream concrete wall of a dam in Ecker (Germany) using two laser scanners characterised by different technical parameters, that is, laser wavelength (laser’s colour), range, definable point density, method of distance measurement – Leica C10, Z+F Imager 5006h. The measurement was carried out in the same weather conditions from the same sites of the test base.

The results of the measurements were analysed using, inter alia, statistical methods by defining template fields and supervised and unsupervised classification methods in reference to the selected fragments of the surface characterised by known concrete surface properties. Various classification algorithms were used. The obtained results make it possible to assess the suitability of the proposed methodology of evaluating the concrete surface’s condition and establish tool selection principles to match the practical application requirements.