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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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.
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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
...
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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
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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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How to visualize inundation using Sentinel 1 SAR Data?
I am trying to visualize flooding after hurricane Harvey that made landfall on August 25-26 2017.
Based on this video, I've been able to obtain the basics of Sentinel-1 SAR imagery. Sentinel 1 comes ...
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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) ...
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Showing overland flow route on DEM in QGIS?
I've been asked to produce a risk map at work which will show the possible flood route from sewers that surcharge (flood) during heavy rainfall. This is basically where I know the x-y coordinate (OS ...
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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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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 ...
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Increasing Flood Plain
I am doing a project where we are attempting to determine how many more buildings would flood if the FEMA flood plain increased by 1',2' and 5'. I have the elev of the flood plain rasters from lidar ...
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Creating contours based on polyline using ArcMap?
I would like to create a simple floodplain map. I have LiDAR data with 1 meter accuracy. I have clipped it to a small area of interest that my computer can handle processing the LiDAR. I want to ...
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Calculating area in QGIS, defined as zone with relative elevation compared to a river
I’m trying to do the following in QGIS. When creating a 3D map, I want to follow a line or area of interest, such as a river, and create an area which is measured perpendicular to the line of interest,...
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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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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 ...
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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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How to find out which areas are affected by flooding due to heavy rain?
I'm working on a little project to visualize affected streets of flooding due to heavy rain. I already got a DEM for my study area and filled the depressions with r.fill.dir.
Since I never worked on ...
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Creating flood area based on connected pixels of DEM in ArcGIS Desktop?
I am trying to show the area of flooding that occurs when bodies of water increase by different increments, like 0.5, 1, 1.5 meters, etc.. for all of Tanzania. I have a DEM with all of the bodies of ...
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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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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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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). ...
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Correspondence of 0m elevation height of a digital elevation model (Copernicus DEM) to mean sea level
I want to model future coastal flooding caused by sea-level rise under the latest IPCC scenarios at global scale. To this end, I use the Copernicus Digital Elevation Model (Copernicus DEM: https://...
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Converting polyline to polygon in ArcGIS Desktop for floodplain map?
I'm using ArcGIS Desktop 10.5 and working with a flood map from FEMA, which uses polylines with distinct attributes for each hazard zone (1%, 0.2%, floodway, etc). I'm trying to convert these ...
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Locating flooded area by creating buffer with elevation around points using ArcGIS Desktop?
I have a shapefile with points, that each have an elevation in their attribute tabel, based on how high the water level is, at a given return period. I need to create a buffer around these points at ...
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Substracting rasters using ArcGIS Raster Calculator?
I need to adjust a DEM (raster) and I was wondering if the Raster Calculator is the right tool to use, and how?
I’m modelling floods in Xochimilco (Mexico) and via OpenStreetMap I have acquired the ...
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What Algorithms to use for Levee breach Analysis?
I have a (relatively) High resolution DSM of the Country side, and want to figure out the extent of area that will be flooded if the Embankment/levee fails at a a given point.
Something like this: ...
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Creating cumulative friction map
I am looking at bottom friction (Manning's n) values in relation to storm surge as large volumes of water flow over a surface.
In order to calculate total head loss occurring as water passes from the ...
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ArcGIS Calculate flooding area based on input amount of water
I have created a DEM based on historical maps from 1816. I'm supposed to calculate the flooded area for certain amounts of water (in m³/s).
I intended to do it with ArcHydro - however, as far as I ...
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How to approximate the elevation of a shapefile in any pixel of a grid using a digital terrain model?
Introduction
I am working on some flood maps of a given region. As the data is confidential, I will try to stay as general as possible without any loss of relevant information. The truth is, my ...
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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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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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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 ...
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Offset raster boundary by elevation
I've been given a raster with flood elevation limits along a river, it's not a constant flood level so elevations range by ~35m. I need to do an analysis of the impacts if these elevations were 2m ...
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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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How to design a flood with water elevation on a specific point?
Actually I have to know the flooding area caused by a rise of the water level due to the implementation of a dam.
So I would like to know if there is an extension or any tool in QGIS or GRASS which ...
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Issue with FEMA OGC Web Feature Service returning HTTP 400 error when attempting to download GML file
I'm trying to use an OGC web feature service in some software I am involved in developing. The service is described at the bottom of this page: https://hazards.fema.gov/femaportal/wps/portal/NFHLWMS
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HEC-RAS limitation on cross sections?
For every cross-section profile, Manning's value is assigned.
There are numerous values in a single cross-section profile but HEC-RAS allows only 20 values per cross-section.
How can I deal with ...
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Detect sharp changes in elevation
I've been scouring the forums to see if there is a way to detect sharp, unnatural elevation changes greater than a certain amount in ArcGIS Pro. I've run across an issue in some DEMs where there are ...
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Displaying water movement paths over grid in QGIS
I have an external .csv file with "From" cell, "To" cell, X, Y coordinates for the "From" cell, X Y coordinates for "To" cell and flow rate for water going from ...
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Layer error: Image.rename: The number of names (1) must match the number of bands (10)
I am using Landsat 7 data (ee.ImageCollection("LANDSAT/LE07/C01/T1_TOA")) for flood mapping. I am trying to write the code but I'm stuck at a line where it says "Layer error: Image....
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Converting a point file, into a smoother set?
I am currently attempting to show how a coastal area was flooded from the 2010 Mentawai Ocean tsunami on the Pagai Islands. I currently have a DEM and a DEM which I have sourced from a point data set, ...
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Explanation of HAND (height above nearest drainage) model procedure
i tried to follow this procedure Spatial Analysis - Calculate a cells elevation (height) above the nearest stream cell but i have some problem to understand everything. I mean the 2th answer in the ...
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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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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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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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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 ...
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Urban watershed delineation for flash flood events
I am currently trying to create urban watersheds using the ending points of flash flood events (in the NOAA Storm Events Database) as outlet points for a city. While doing so, the watershed that is ...
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Issues implementing data fusion in EO Browser
I am trying to implement this custom script for flood mapping in EO Browser. I have added the datasets using the additional datasets button, and specified the required timelines, but I keep getting ...
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QGIS - How to split and display Population Data according to District/Province?
I'm a complete beginner in QGIS, currently self-teaching myself through Youtube.
Current Problem: To split and display population data according to district/province
Project Background: To measure ...
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Generate topographical index from a digital surface model (DSM) to generate a flood susceptibility map [closed]
I'm performing a random forest model to generate a flood susceptibility map, I have LiDAR data from the study area where I generated Digital Surface Model (DSM) and Digital Terrain Model (DTM) raster ...
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How do I calculate high water extents?
Could someone suggest the right path to follow if I were looking to calculate the high water extents or potential flooding that could occur on a tidal river. I am working in ArcGIS Pro and have ...
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