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 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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Finding Vector data that is in the area of a specific value of Raster data
I am doing a flooding analysis and would like to know how many roads would be flooded at certain elevations. The roads are in vector data format, while the elevation information is in raster. What ...
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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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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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Using Python to extract flood hazard info from National Flood Hazard Layer (NFHL) using any given lat/long point? [closed]
Can Python be used to extract flood hazard classifications from National Flood Hazard Layer (NFHL) site using any given lat/long point?
Specifically the following seven classifications:
1% Annual ...
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Generate flood map using qgis [closed]
How can I generate a flood inundation map and flood depth using QGIS within 3 hours?
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Flood Plain Mapping using HEC-GeoRAS and ArcMap?
How can I get complete bounding polygon of XS CutLines for flood plain mapping (Flood Inundation Mapping) using HEC-GeoRAS and ArcMap 10.3?
When I tried to perform this task, the bounding polygon ...
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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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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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Flood Inundation Mapping In HEC-RAS?
I'm getting this output as a result of discharge values while doing flood inundation mapping.
In some areas there are breaks as indicated by red arrows.
If this result is correct what would be the ...
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Exporting complete river profile from hec-ras into ArcMap?
Whenever i import the data from hec-ras the result is the same, what mistake am i making here?
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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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Solving computing time problem when grid size element increases in flood model?
I want to create high resolution and high accuracy "area of inundation" map using FLO-2D Model. I have high resolution Digital Elevation Model (DEM) and I must show small topographic details on my ...
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DEM showing areas in the ocean to be greater than 0m (my MSL in my project)
I am a new GIS student currently working on a coastal flood model in arc map, where I intend to create flood polygons at various heights above 0m contour (MSL)to represent the extent of area flooded ...
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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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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 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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Estimating population in flood zones?
I have a census tract shapefile with the population of a minority group and total population.
I am trying to analyze this group by high and low risk flood zones.
The problem is that not all of 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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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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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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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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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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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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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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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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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 ...
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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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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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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 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 ...
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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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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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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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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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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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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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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 ...
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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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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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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 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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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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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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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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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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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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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?
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