Wyniki wyszukiwania - BazTech

1

Flood Vulnerability Mapping and Risk Assessment Using Hydraulic Modeling and GIS in Tamanrasset Valley Watershed, Algeria

Madi Housseyn, Bedjaoui Ali, Elhoussaoui Abdelghani, Elbakai Lala Oulad, Bounaama Aya

Journal of Ecological Engineering

|

2023

|

Vol. 24, nr 7

35--48

EN

The paper is focused on the integration of the US Army Corps of Engineers Hydrologic Engineering Center (HEC) models, particularly the HEC-RAS (River Analysis System) 1D hydraulic model, into a decision support system for predicting the effects of floods. The study was conducted in the Tamanrasset Valley watershed in Algeria, where the HEC-RAS model was used to calculate water flow profiles for various flood events that occurred downstream. The objective of the study was to generate flood maps for extreme river flood events in the area, which could help assessing the risk of flood vulnerability in the area study. The process involved using the HEC-RAS 1D model to simulate the water flow in the river, taking into account the various flow and boundary conditions. The results of the simulation were then exported and analyzed in GIS-based software, HEC-GeoRAS, to prepare the flood inundation maps. The flood maps were based on the water level at each cross-section, which was calculated using the water surface profiles generated by HEC-RAS. The study aimed to identify flood zones using a combination of HEC-GeoRAS and GIS. The HEC-GeoRAS extension was utilized in a GIS environment to determine flood zones associated with 10-year, 20-year, 50-year, and 100-year return periods. The results of the study confirmed the effectiveness of the integration of GIS and HEC-RAS and demonstrated the performance of the model. Based on these findings, the study recommends the application of this model in planning and management programs for both residential and agricultural areas, to ensure appropriate measures are taken for future flood defense.

2

ArcGIS Desktop jako narzędzie wspomagające proces modelowania wezbrań powodziowych

Czajkowska A., Osowska J.

Systemy Wspomagania w Inżynierii Produkcji

|

2016

|

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.

3

Digital Terrain Model as a basis for determining the floodland of the Prądnik river

Litwin U., Piech I., Rakowski D.

Geomatics, Landmanagement and Landscape

|

2015

|

no. 2

55--61

EN

The modern technology gives us the possibility to make a Digital Terrain Model, which is more and more frequently used in various scientific fields. Localizing the floodland on the basis of Digital Terrain Model provides an insight into the reality and is relatively quick. On the basis of the materials from photogrammetric flight the Digital Terrain Model was prepared, which was measured at the digital station “Delta”. The model has been supplemented by elements of land cover, that is meadows and pastures, built-up areas, roads, escarpments, forests and waters. By using the software Surfer a spatial (3-D) model of a studied area has been created. The floodland of the Prądnik river, when the water level is higher by 2 and 5 meters, have also been visualised.

PL

Nowoczesna technologia umożliwia utworzenie Numerycznego Modelu Terenu, który coraz częściej jest wykorzystywany w różnych dziedzinach nauki. Określanie terenów zalewowych na podstawie Numerycznego Modelu Terenu daje wgląd w rzeczywistość, a przy tym jest stosunkowo szybki w realizacji. W oparciu o materiały z nalotu fotogrametrycznego, opracowano Numeryczny Model Terenu, który pomierzono na stacji cyfrowej „Delta”. Model ten uzupełniono o elementy pokrycia terenu tj. łąki i pastwiska, tereny zabudowane, drogi, skarpy, lasy oraz wody. Wykorzystując oprogramowanie Surfer stworzono przestrzenny model opracowywanego terenu. Dokonano również wizualizacji stref zalewowych rzeki Prądnik, gdy poziom lustra wody jest wyższy o 2 i 5 m.

4

Modelling of Flood Hazard Zone for the Łęg River

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

Geomatics and Environmental Engineering

|

2013

|

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.

5

Wpływ jakości danych na modelowanie stref zagrożenia powodziowego

Hejmanowska B.

Roczniki Geomatyki

|

2006

|

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.