High-accuracy mapping of inundations induced by ice jams: a case study from Iceland

2012 ◽  
Vol 43 (4) ◽  
pp. 412-421 ◽  
Author(s):  
Emmanuel Pagneux ◽  
Árni Snorrason
Keyword(s):  
Flood Hazard ◽  
Numerical Models ◽  
Open Water ◽  
Flood Hazards ◽  
Hydraulic Modelling ◽  
Photo Interpretation ◽  
Ice Jams ◽  
Ice Jam ◽  
Digital Elevation ◽  
Elevation Model

Hydraulic modelling is widely used for deriving flood hazard maps featuring depth of flooding and flow velocity from discharge scenarios. Due to uncertainties about flow conditions or inaccurate terrain models, flood hazards maps obtained from hydraulic modelling may be of limited relevance and accuracy. Hydraulic modelling is particularly challenging in Arctic regions, where ice jams lead to flooding in areas that would not be subjected to inundation under open-water conditions. As numerical models of ice jam processes require information that may be difficult and expensive to collect, an alternative approach based on the photo interpretation of documented historical events is presented here. Orthophotographs and a digital elevation model at high resolution are used to support the photo interpretation process. Tested in an Icelandic watershed prone to ice jam floods, reconstructions provide locally unprecedented and robust information on the extent and depth of flooding of inundations induced by ice jams.

scholarly journals Ice jam flood risks on the rivers of the Baikal Basin

2020 ◽  
Vol 163 ◽  
pp. 02001
Author(s):  
Tatyana Borisova
Keyword(s):  
Negative Impact ◽  
Flood Hazard ◽  
Hazard Analysis ◽  
Lake Basin ◽  
Baikal Lake ◽  
Ice Jams ◽  
Damage Area ◽  
Selenga River ◽  
Ice Jam ◽  
Rational Development

The article presents the results of analysis and assessment of risks related to ice jams on the rivers of the Baikal Lake Basin. It also proposes the recommendations for mitigation and rational development of coastal areas. Data on catastrophic ice jam floods for more than 100 years is presented, the factors of their formation and mechanism of their movement are considered. On the basis of official statistics from expedition surveys, potentially dangerous jamming areas have been identified, and the repeatability and extent of floods have been calculated. With the help of ArcGIS package the scale of possible flooding was determined, which allowed to reveal the list of economic objects within the damage area. Specific indicators have been used to calculate the expected damage to territories, facilities and population from the flood hazard. Analysis and assessment of economic risk from the floods on the Selenga River are given. Measures to minimize risks of negative impact of floods are proposed.

scholarly journals One-Dimensional (1D) River Analysis of a River Basin in Southern Luzon Island in the Philippines Using Lidar Digital Elevation Model

2018 ◽  
Vol 7 (3.7) ◽  
pp. 29
Author(s):  
Fibor J. Tan ◽  
Edgardo Jade R. Rarugal ◽  
Francis Aldrine A. Uy
Keyword(s):  
Digital Elevation Model ◽  
Flood Hazard ◽  
Monsoon Season ◽  
Extreme Rainfall ◽  
The Philippines ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
One Dimensional ◽  
Digital Elevation ◽  
Elevation Model

Flooding is a perennial problem in the Philippines during the monsoon season intensified by the effects of typhoon. On average, there are 20 typhoons that enter the Philippine Area of Responsibility (PAR), and many of these make landfall causing catastrophic aftermath. Extreme rainfall events could lead to flooding in the downstream floodplain and landslide in mountainous terrains. In this study, which is for the case of Calumpang River that drains to the populated and developing region of Batangas City, the focus is on flooding in the floodplain areas. The river was modelled using LiDAR digital elevation model (DEM) that has an accuracy of 20cm in the vertical and 50cm in the horizontal. The result of this is river hydraulic model that can be used to accurately generate flood inundation simulations and flood hazard maps.  

Magma system pressurisation and long-term surface deformation at Soufrière Hills Volcano, Montserrat

2021 ◽  
Author(s):  
James Hickey ◽  
Karen Pascal ◽  
Matthew Head ◽  
Jo Gottsmann ◽  
Nico Fournier ◽  
...  
Keyword(s):  
Surface Deformation ◽  
Numerical Models ◽  
Three Dimensional ◽  
Magmatic System ◽  
System Pressure ◽  
Digital Elevation ◽  
Elevation Model ◽  
Magma System ◽  
Continuous Gps

<p>Soufrière Hills Volcano (SHV) is an andesitic dome-building volcano on the island of Montserrat (British West Indies). SHV began its current, and anomalously long, eruption in 1995, but eruptive activity has been intermittent with phases of lava extrusion separated by periods of relative quiescence. The current pause in eruption started in February 2010 and is the longest yet recorded, 10 years and 11 months at the time of writing (January 2021). Continuous GPS measurements show island-wide inflation from 2010 onwards, with the rate of inflation slowly decreasing with time. However, the length of the eruptive pause raises questions as to whether there have been significant changes to the magmatic system and/or the eruption at SHV might have ended. To assess the behaviour and evolution of the SHV magmatic system since 2010 and the relation to ongoing hazard assessment, we analyse the continuous GPS temporal deformation trends using a suite of geodetic numerical models. Our models incorporate a temperature-dependent viscoelastic rheology, topography derived from a Digital Elevation Model and three-dimensional variations in mechanical properties derived from seismic tomography. The models are driven using one of four possible time-dependent source functions, to simulate differences in the temporal evolution of the magmatic system. The results show that the observed deformation data requires a temporal source function whereby the magmatic system pressure is increasing with time. A viscoelastic crustal response cannot explain the long-term deformation trends alone. The nature of the source pressurisation is unclear, and could be due, for example, to one or a combination of, magma supply, degassing/volatile influx, or overturning within a transcrustal magmatic system. Continued pressurisation within the magmatic system highlights the need for sustained vigilance in the monitoring and management of the volcano and its surroundings.</p>

scholarly journals Are Feature Agreement Statistics Alone Sufficient to Validate Modelled Flood Extent Quality? A Study on Three Swedish Rivers Using Different Digital Elevation Model Resolutions

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Nancy Joy Lim ◽  
Sven Anders Brandt
Keyword(s):  
High Resolution ◽  
Performance Measures ◽  
Roughness Parameter ◽  
Flood Insurance ◽  
Full Potential ◽  
Hydraulic Modelling ◽  
Digital Elevation ◽  
The World ◽  
Elevation Model ◽  
Global Agreement

Hydraulic modelling is now, at increasing rates, used all over the world to provide flood risk maps for spatial planning, flood insurance, etc. This puts heavy pressure on the modellers and analysts to not only produce the maps but also information on the accuracy and uncertainty of these maps. A common means to deliver this is through performance measures or feature statistics. These look at the global agreement between the modelled flood area and the reference flood that is used. Previous studies have shown that the feature agreement statistics do not differ much between models that have been based on digital elevation models (DEMs) of different resolutions, which is somewhat surprising since most researchers agree that high-resolution DEMs are to be preferred over poor resolution DEMs. Hence, the aim of this study was to look into how and under which conditions the different feature agreement statistics differ, in order to see when the full potential of high-resolution DEMs can be utilised. The results show that although poor resolution DEMs might produce high feature agreement scores (around F > 0.80), they may fail to provide good flood extent estimations locally, particularly when the terrain is flat. Therefore, when high-resolution DEMs (1 to 5 m) are used, it is important to carefully calibrate the models by the use of the roughness parameter. Furthermore, to get better estimates on the accuracy of the models, other performance measures such as distance disparities should be considered.

Ice jam release surges, ice runs, and breaking fronts: field measurements, physical descriptions, and research needs

2003 ◽  
Vol 30 (1) ◽  
pp. 113-127 ◽  
Author(s):  
Martin Jasek
Keyword(s):  
Unsteady Flow ◽  
Field Measurements ◽  
Open Water ◽  
Two Phase ◽  
Ice Jams ◽  
Water Ice ◽  
Flow Models ◽  
Ice Jam ◽  
Recent Developments ◽  
Break Up

Surges or flood waves made up of ice and water resulting from the release of ice jams can be destructive to life and property and are also one of the more complicated problems in river ice engineering. The interaction between the ice mechanics and unsteady flow leads to results that are often unpredictable with open water unsteady flow models. There are considerable differences of opinion on the degree of significance of this water–ice interaction. There have also been recent developments in two-phase unsteady flow modelling which are capable of handling these complicated situations. It is the aim of this paper to present both quantitative data and qualitative observations on ice runs and breaking fronts to provide insight to the physical processes involved as and possible sources of model calibration data.Key words: ice jam, surge, unsteady flow, ice run, ice jam release, breaking front, break-up, breakup, break-up front.

scholarly journals Spatial Modeling of Flood Sea Tides (Case Study: East Coast Semarang)

2004 ◽  
Vol 18 (1) ◽  
Author(s):  
Muhammad Aris Marfai
Keyword(s):  
Open Space ◽  
Flood Hazard ◽  
Hazard Analysis ◽  
Spatial Modelling ◽  
Flood Level ◽  
Digital Elevation ◽  
Elevation Model ◽  
Gis Software ◽  
The Impact

The aims of this research are 1) to construct a spatial model of tidal flood hazard, 2) to do hazard analysis of tidal flood. Spatial modelling has been generated using Geographic Information System (GIS) software and ILWIS software was seleccted to do the model operation. Neighborhood function and digital elevation model (DEM) have been applied on the modelling calculation process. DEM data was correted and menipulated using map calculation on the digital form. Tidal flood hazard analysis has been done by means of map calulation on the tidal flood hazard map and detail landuse map. Histogram and tabulation from the result of the map calculation have been analyzed to identify the impact of the tidal flood hazard on the landuse. The highest impact of the tidal flood hazard occurs on the 1 meter of tidal flood level, where in the inundation occurs mainly on the fishpond and yard/ open space area.

scholarly journals INFLUENCE OF DEM IN WATERSHED MANAGEMENT AS FLOOD ZONATION MAPPING

2016 ◽  
Vol XLI-B8 ◽  
pp. 3-10
Author(s):  
Muhamad Alrajhi ◽  
Mudasir Khan ◽  
Mohammad Afroz Khan ◽  
Abdalla Alobeid
Keyword(s):  
Flood Hazard ◽  
Geographical Information ◽  
Hydrological Models ◽  
Flood Hazards ◽  
Remotely Sensed Data ◽  
Coverage Area ◽  
Drainage Patterns ◽  
Research Organizations ◽  
Digital Elevation ◽  
Working Groups

Despite of valuable efforts from working groups and research organizations towards flood hazard reduction through its program, still minimal diminution from these hazards has been realized. This is mainly due to the fact that with rapid increase in population and urbanization coupled with climate change, flood hazards are becoming increasingly catastrophic. Therefore there is a need to understand and access flood hazards and develop means to deal with it through proper preparations, and preventive measures. To achieve this aim, Geographical Information System (GIS), geospatial and hydrological models were used as tools to tackle with influence of flash floods in the Kingdom of Saudi Arabia due to existence of large valleys (Wadis) which is a matter of great concern. In this research paper, Digital Elevation Models (DEMs) of different resolution (30m, 20m,10m and 5m) have been used, which have proven to be valuable tool for the topographic parameterization of hydrological models which are the basis for any flood modelling process. The DEM was used as input for performing spatial analysis and obtaining derivative products and delineate watershed characteristics of the study area using ArcGIS desktop and its Arc Hydro extension tools to check comparability of different elevation models for flood Zonation mapping. The derived drainage patterns have been overlaid over aerial imagery of study area, to check influence of greater amount of precipitation which can turn into massive destructions. The flow accumulation maps derived provide zones of highest accumulation and possible flow directions. This approach provide simplified means of predicting extent of inundation during flood events for emergency action especially for large areas because of large coverage area of the remotely sensed data.

Floodplain Delineation Based on Analysis of Digital Elevation Model, Soil Maps and Occurrence of Quaternary Formations

2019 ◽  
Vol 31 (1) ◽  
pp. 29-47
Author(s):  
Aleksandra Kozłowska
Keyword(s):  
Digital Elevation Model ◽  
Flood Hazard ◽  
Hazard Maps ◽  
National Research Institute ◽  
Model Soil ◽  
Main River ◽  
Digital Elevation ◽  
Elevation Model ◽  
Floodplain Delineation ◽  
Mountainous River

Abstract This paper presents a GIS based method of indicating flood extent in a mountainous river basin. Only main river with the valley is object of this analysis. The approach used in this work combines analysis of digital elevation model (DEM) obtained from LIDAR data with presence of alluvial soils and quaternary formations. In addition, in this article an attempt of calculating flood wave height for delineated floodplain is presented. The results are compared with floodplains derived from one of the products of country-scale project „IT system for protection against extraordinary hazards” (ISOK) which are flood hazard maps and with the extent of The Great Flood of 1997. Indication of the area flooded during Poland’s Great Flood in July 1997 is based on the hydrological data from Institute of Meteorology and Water Management – National Research Institute (IMGW – PIB).

Analysis of breakup and ice jams on the Athabasca River at Fort McMurray, Alberta

1984 ◽  
Vol 11 (3) ◽  
pp. 444-458 ◽  
Author(s):  
D. D. Andres ◽  
P. F. Doyle
Keyword(s):  
Internal Friction ◽  
Open Water ◽  
Water Levels ◽  
Roughness Coefficient ◽  
Produce Water ◽  
Ice Jams ◽  
Athabasca River ◽  
Fort Mcmurray ◽  
Ice Jam ◽  
Clearwater River

During breakup, severe ice jams form at Fort McMurray, Alberta because of the dramatic change in the character of the Athabasca River at that location. Such jams, which produce water levels in the order of 10 m above the normal open water stage, were documented in 1977, 1978, and 1979. Additional channel surveys and improved estimates of discharge made since the initial analysis have redefined the ice jam characteristics. The Manning roughness coefficient of the underside of the ice jams was found to be 0.072. The new discharge estimates, which were up to twice those previously reported, result in a calculated coefficient of internal friction of 0.8–2.7. This is 30–100% greater than previous estimates, but still similar to values determined for ice jams at other locations.Even with the variation in the coefficient of internal friction, the river stage due to an ice jam at Fort McMurray could be computed with reasonable accuracy for a range of given discharges. If jams form downstream of the mouth of the Clearwater River at discharges greater than 800 m3/s (considerably less than the 1-in-2-year open water flood), flooding will occur within lower Fort McMurray. Unfortunately, the frequency of such an event is unknown because the probabilities of both the discharge being exceeded and the jam occurrence cannot be defined. Key words: ice, breakup, ice jam, ice roughness, flooding, hydraulics.

scholarly journals Flood Hazard Mapping by Using Geographic Information System and Hydraulic Model: Mert River, Samsun, Turkey

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Vahdettin Demir ◽  
Ozgur Kisi
Keyword(s):  
River Basin ◽  
Flood Risk ◽  
Flood Hazard ◽  
Human Life ◽  
Hydraulic Model ◽  
Hazard Mapping ◽  
Digital Elevation ◽  
Risk Maps ◽  
Analysis System ◽  
Elevation Model

In this study, flood hazard maps were prepared for the Mert River Basin, Samsun, Turkey, by using GIS and Hydrologic Engineering Centers River Analysis System (HEC-RAS). In this river basin, human life losses and a significant amount of property damages were experienced in 2012 flood. The preparation of flood risk maps employed in the study includes the following steps: (1) digitization of topographical data and preparation of digital elevation model using ArcGIS, (2) simulation of flood lows of different return periods using a hydraulic model (HEC-RAS), and (3) preparation of flood risk maps by integrating the results of (1) and (2).

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