Questions tagged [flood]
A flood is an overflow of water that submerges land which is usually dry. Within GIS we often want to model a flood with terrain models.
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How to add hypothetical values to a raster?
I have to create Non-Regulatory Products for a few FEMA regions. Right now I am working on the 'Increased Flooding Scenarios' where you add a hypothetical value to the existing Base Flood (1', 2', and ...
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1answer
3k views
Calculating Flooded area / Inundation in ArcGIS for Desktop?
I was tasked to create a layer with the flooded areas if the sea / river level was to go up by X feet. There is no requirement to take Flow and Pour Points into account, just a simple raise in water ...
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1answer
381 views
Extracting features from raster data using ArcGIS Desktop?
I want to extract flood related pixels from my imagery.
I calculated mLSWI(Modified Land Surface Water Index).
According to the literatures, mLSWI >= 0.5 is flood pixels.
How do I identify the ...
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0answers
733 views
Flood mapping in QGIS 2.4
I am trying to delineate flood-prone areas using QGIS.
I have a vector layer of the river and a DEM of the same area.
I have used the GRASS Module to get watershed by using r.watershed and I have ...
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1answer
122 views
Advice on Flood mapping of village area [closed]
This is my first attempt to do a study on this topic.
I would like to get some advice on what data are required for doing flood mapping.
The area I have selected for this is a village which faces ...
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1answer
1k views
How to extend a (river water level) raster, transfering its values to the added area?
Exploring the raster tools in QGIS and related software, I found raster buffer functions to surround existing rasters. The values of the raster buffer are restricted to be distances from the interior ...
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1answer
383 views
Getting flood depth grid values for road segments?
I have a 2 features, the first contains values for flood depth (Raster, GRID). the other is a road network (vector, polyline) that has been clipped to the boundary of the depth grid. I am racking my ...
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0answers
56 views
Where can I obtain data on flood sites, land sewage systems, and property value?
I am a college student trying to obtain this data for a class project. If anyone can help that would be great. Basically, my hypothesis for this project is that land sewage systems that have not been ...
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0answers
1k views
How to make an inundation map?
My task is to calculate the area available for specific plant species in a natural reserve that has been reconnected to the tidal influence.
First step is to create an inundation map for a natural ...
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0answers
98 views
What is the background processing of rainfall thresholding?
I want to create a flood map using Quantum GIS. First of all I create catchment area (flow accumulation). Then, I delineate a Channel Network by applying a threshold to flow accumulation. So I want to ...
2
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1answer
932 views
map flood inundation risk QGIS
I am using RADAR data to create a map of biomass estimates.
I want to mask out all land susceptible to flooding because water-logged soils affect the backscatter ...and will have an impact on ...
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0answers
528 views
Simulating flood without flooding whole area and covering surface structures (with DEM)? [closed]
I have a high resolution DEM and want to do a flood simulation starting at a river. My hope is that the water runs into historical (now dry) river channels (in which I'm interested in) at first and ...
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1answer
237 views
What is the process for identifying a 20 year flood zone?
I am currently working on an assignment where I need to model flood risk areas. Firstly I was asked to identify potential flood risk zones based on the following criteria:
identify areas that I would ...
0
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1answer
204 views
Urban Hydrology Using With GIS
I'm researching how can I create a model urban floodplain depending on rainfall. And Which programme should I use? I want to show floodplain depending on temporal and spatial distribution on study ...
2
votes
1answer
836 views
Flood Elevation Setback
I have a floodplain layer with elevations assigned to it. Per scope of the project, I need to create a safety setback. The flood elevation is raised by 2 ft. and when the raised point extended ...
2
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1answer
95 views
Obtaining free satellite imagery for Australian floods?
How can I obtain free satellite imagery for Australia? I want to find the extend of flood in specific time. I have already tried land-sat.But unfortunately there is no data available for that specific ...
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0answers
91 views
flood mitigation
I would like to carry out flood mitigation using non-structural measures like wetland restoration, detention ponds and infiltration ditches or ponds. How can GIS help me in siting and visualizing the ...
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1answer
1k views
Digital Elevation Model resolution [closed]
When I create flood areas using DEM in ArcGIS, which parameters do I consider to determine DEM's pixel size and resolution?
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0answers
373 views
Multicriteria Analysis for flood risk analysis
I have used a multi-criteria analysis which uses factor weighting for flood risk identification in a river basin using ArcGIS 10.1. My factors are rainfall, drainage, density, slope, and land use.
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2answers
2k views
Simplified flood “model” / estimation from elevation data
The goal is to present an estimation of potential flooded area. But still keeping it simple.
I know this will not be accurate. The question is:
will it be good enough for at gestimate / rough ...
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vote
1answer
3k views
Creating weight raster for flow accumulation in ArcGIS for Desktop?
I am studying flood flow using ArcGIS for Desktop.
When creating flow accumulation in hydrology, there is a weight raster.
However, İf you do not have it, the programme sets its value to 1 which is ...
2
votes
1answer
755 views
Obtaining average value around polygon in raster for different cross sections?
I have elevation data in a raster, river (blue line) and the flooded area (black polygon) as shown in the image below:
I want to find the water depth in the flooded area (inside the black polygon). ...
2
votes
2answers
768 views
Storm Water flooding [closed]
Is there a method in Arc Gis for mapping storm water runoff in an urban environment assuming that the sewers are at full capacity. I just want to map roughly where the water will flow over the land ...
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1answer
551 views
Flood records/database in Europe
Anyone knows where I can find a complete* database with the historic flood occurrence in Europe, at least since the 70's ?
I am looking for some information on the date, number of floods*, amount ...
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1answer
652 views
How to map flood areas from a set of points containing surface and height of water?
I am working on the damages made by the typhoon Haiyan. I use QGIS 2.0 with extensions and toolbox, and MapInfo. I have vectors, rasters of the place.
I want to map the flood area along the ...
2
votes
1answer
1k views
Is there flood map prediction tutorial available to use with ArcGIS for Desktop? [closed]
I just want to ask if anyone knows a direct tutorial for flood mapping prediction.
The scenario that my supervisor asked me is this:
If we pour water on a specific location, where will it flow and how ...
8
votes
1answer
4k views
Calculating flood volume using LiDAR DEM and HEC-RAS floodplain polygon?
I’ve got a vexing GIS analysis problem which is
conceptually fairly straightforward, but in reality more challenging to figure out….
Basically, I need to calculate the VOLUME of floodwater within a
...
9
votes
2answers
6k views
Is it possible to conduct a flood model analysis with QGIS using a DEM?
Is it possible to conduct a flood model analysis with QGIS using a DEM? Need to simulate rising water levels on a 250k map.
6
votes
1answer
813 views
Floor height creation from Aerial Lidar/Imagery only
I was wondering if it is possible to generate the floor heights of buildings from aerial lidar? We don't have terrestrial lidar or stereo imagery. I don't need the ground DEM level or the roof (DSM) ...
9
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2answers
4k views
Generating floodplain generation given river section polylines, flood level elevation points and DEM of land surface? [closed]
I am looking to generate flood plain polygons to represent 20 and 100 year flood zones, in the most accurate and efficient way possible, given the following datasets:
River cross section polylines
...
0
votes
2answers
509 views
Belgium Flood And Precipitation Mapping
Similar to Free sources of mapping data for France, does any one know a source for free downloadable flood and precipitation maps for Belgium?
