Wyniki wyszukiwania - Biblioteka Nauki

1

Wpływ jakości danych na modelowanie stref zagrożenia powodziowego

100%

Hejmanowska B.

|

2006

|

tom T. 4, z. 1

145-150

EN

The aim of INSPIRE programme is to assure an easy access to reliable spatial information. Spatial data should thus be reliable and the degree of its reliability should be known and information about it should be contained in the database. Reliability of data is proved by its quality, which should be taken into account when GIS systems are used to support decisions, for instance, in modeling of flood risk areas. Coordination-Information Centers (OKI) of flood protection in Regional Water Management Boards set up within the framework of a Word Bank project .Removal of flood effects. deal, among others with mapping of flood risks [http://oki.krakow.rzgw.gov.pl]. Areas of flood risks, also called flooding areas, and their reach, are outlined based on historical or hypothetical data (assuming determined probability of a given water level, e.g. for water 1%, or water level probable to appear once in 100 years). Two types of flood risks areas distinguished: direct risk areas and potential risk areas. Direct flood risk areas are adjacent to water flow and cover terrain flooded when the river overflows floodbanks. Potential flood risk areas are the areas in danger of floods when there is a damage of floodbanks. Spatial reach of the area is outlined as a result of GIS analysis of intersection of the surface of water table with Digital Terrain Model (DTM). The accuracy of DTM is varies from +/-0.2m for floodbanks to +/-2.5m in the area with diversified lie of the land (gradient higher than 6 degrees). The risk of flood is usually associated with probability of a certain water level. However, there is other kind of risk, connected with analytical side of outlining flood areas, including first of all the quality of source data. When data is complete and up to date, the main parameter featuring the quality of data is their accuracy. In this case accuracy of source data may be understood as the accuracy of DTM and the accuracy of outlining the level of water table (e.g. based on hydrological modeling). The risk connected with not taking into account the quality of source data in modeling flood areas may be calculated on the basis of a formula [Kapłan S., Garrick B.J, 1981 . .On the quantitative definition of risk., Risk Analysis 1981]: R = S ź P ź C where: S . scenario, P . probability of scenario S taking place, C . measure of effects of the scenario S. The key issue is the probability (P) of scenario (S) taking place. Let us assume, for instance, scenario S (e.g.. water 1%). On the basis of spatial distribution: inaccuracy of DTM and water table may generate a map of probability distribution for a given terrain to be flooded, instead of a flood line traditionally outlined. When analyzing objects at potential risk we may assign to them .measure of effects. caused by flood, e.g. financial measure. Then, in the result of spatial analysis a map of risk distribution may be generated, based on the above formula, connected with outlining a given flood area based on source data with accuracy determined in the beginning. The paper presents an example of modeling a flood area taking into account and neglecting inaccuracy of source data. On this basis, the risk connected with not taking into account the quality of source data in modeling of flood risk area may be analyzed.

2

Modelling of Flood Hazard Zone for the Łęg River

84%

Głowienka-Mikrut E. , Michałowska K. , Mikrut S. , Nałęcz T. , Mroczka T.

|

2013

|

tom Vol. 7, no. 4

31--41

EN

This article presents an update of flood hazard map for the 4 km strip of land along the Łęg River below the water reservoir dam in the village of Wilcza Wola, in the district of Kolbuszowa (the Podkarpackie Province), Poland. To produce the map, the hydrological model for a hypothetical flood caused by construction disaster of the water reservoir dam in Wilcza Wola was used. Based on the DTM and cross-sections of known flood wave profiles, flood zone for the examined river section was outlined. Also, the impact of the possible flood on inhabitants of the area concerned, and on selected land surface objects, was examined.

PL

W artykule przedstawiono aktualizację mapy zagrożenia powodziowego na 4-kilometrowym pasie terenu wzdłuż rzeki Łęg, znajdującym się poniżej zapory zbiornika wodnego w miejscowości Wilcza Wola, w powiecie kolbuszowskim (województwo podkarpackie). Do sporządzenia mapy strefy zalewowej wykorzystano model hydrologiczny hipotetycznej powodzi powstałej w wyniku katastrofy budowlanej zapory zbiornika w Wilczej Woli. Na podstawie NMT oraz przekrojów o znanych rzędnych wysokości fali powodziowej przy wykorzystaniu modelu hydrologicznego wyznaczono strefę zalewową na badanym odcinku rzeki. Zbadano także wpływ ewentualnej powodzi na mieszkańców badanego obszaru oraz na wybrane obiekty pokrycia terenu. W tym celu wykonano analizy warstw Bazy Danych Topograficznych.

3

ArcGIS Desktop jako narzędzie wspomagające proces modelowania wezbrań powodziowych

84%

Czajkowska A. , Osowska J.

|

tom z. 5 (17)

74--85

PL

Minimalizacja strat powodziowych jest uzależniona od właściwego wyznaczenia zasięgu stref zalewowych, co wymaga opracowania modelu hydraulicznego w programie MIKE FLOOD. Przygotowanie danych wejściowych do modelu przeprowadza się w programach GIS. Jednym z powszechnie wykorzystywanych programów jest ArcGIS Desktop firmy ESRI. W artykule omówiono wybrane funkcje i narzędzia programu ArcGIS Desktop niezbędne do budowy modelu hydraulicznego na przykładzie zlewni rzeki Kłodnicy oraz wizualizacji otrzymanych wyników w postaci map zagrożenia powodziowego.

EN

Flood losses minimization is dependent on proper determining the extent of flood hazard zones what requires the development of a hydraulic model by means of MIKE FLOOD application. Preparation of the input data for the model is carried out using GIS software. One of the programmes commonly used is ArcGIS Desktop by ESRI. In the article selected functions and tools of the ArcGIS Desktop programme were presented - the functions and tools which are necessary to prepare the hydraulic model and to visualize the obtained results as flood hazard zones.

4

Development of areas by the Vistula river in Warsaw in the context of flood issues as an example of adaptation to climate change

67%

Maciejewska E.

|

nr 4