A watershed is the area of land where all of the water that is under it or drains off of it goes into the same place.

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ArcPy script stops running randomly with no error returned

I am doing a batch watershed and analysis process on 135 points. This script worked great the first time I ran it. Ever since the first time, however, I have had the script stop at random moments. ...
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40 views

River channel is cut after rendering flow accumulation in hec-hms

I'm trying to generate flow accumulation using hec-geohms and I have already done some terrain processing using the DEM. I was really confused what happened, why has the river channel been cut? ...
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44 views

How to determine irrigable acres from a single source/point?

I am trying to graphically depict the exact amount of irrigable acres from a single point, in this case a headgate from a drainage ditch. Basically, I have the original water right decrees (i.e. ...
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38 views

What are definitions of watershed segmentation, local maxima, variable window search, etc (about Lidar for vegetation)?

I am not familiar about Lidar. I want to measure trees height and number of trees. I guess, watershed = to locate the trees, local maxima = to measure trees height. I used these methods in SAGA GIS. ...
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128 views

Watershed delineation?

I'd like to delineate the catchments upstream of the sampling points. In order to do that, I have done the following: Burn the rivers into the DEM using ArcHydro>DEM Manipulation>DEM ...
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213 views

Watershed Segmentation SAGA-GIS

I'm trying to segment a topographic map to vectorize it. I'm using the watershed algorithm of SAGA-GIS. It's working fine with polygons, but with roads or contour lines is not working properly. Here ...
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262 views

Stream Order: Strahler vs Shreve

I am writing a research paper on watershed delineation and I am looking for experiences/opinions/authoritative answers on: What guides a hydrologist when it comes to choosing between Strahler's ...
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70 views

How to join two fields after calculating?

I have been working with two layers and I am trying to join them and turn them into a raster data. The first layer is a watershed layer which I have assigned each shed a location from the center point ...
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469 views

GRASS GIS - r.water.outlet - What is my mistake?

I'm new to GIS - more so in GRASS GIS. I installed GRASS GIS 6.4.3svn in my Windows 7 machine. No problem in installation. Downloaded SRTM-Geotiff file Location, Mapset all o.k Used r.in.gdal to ...
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156 views

Using SWAT model with QGIS

I am trying to use SWAT (Soil and Water Assessment Tool) for watershed management activities. It is a set of commandline tools and needs a complex set of input data some of which can be generated from ...
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260 views

Watershed delineation; how to program

I've been trying to roll my own watershed delineation program, taking a flow direction grid and pour points as input. I coded up a quick search algorithm in Python which inspects the flow direction ...
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138 views

What is most suitable DEM to delineate watershed (from spot height, ASTER and SRTM)?

I have three DEMs of our country which are spot height DEM, SRTM DEM and ASTER DEM. SRTM has 90m resolution and ASTER has 30m resolution. My supervisor told me to delineate watershed using these ...
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236 views

Extraction of stream gradient for branched river networks

At the moment I am working on the extraction of stream gradients for a large basin, as a consequence, rivers are strongly branched.So far, I read through the relevant posts on this site, but so far I ...
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GRASS GIS 6.5SVN : r.watershed failed to display basin and accumulation maps

I am passing DEM and threshold values as inputs.I want to get basin and accumulation as outputs.I tried it in Grass,process was completed.while dispalying result it is showing white screen (both ...
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58 views

ArcGIS ModelBuilder Clip Raster by Polygon Error

My task is to derive the hypsometric integral and hypsometric curve for a lot of drainage basins. Since it is very time consuming to do this manually, i have created a model (with help from this ...
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30 views

QGIS DEM Output cell size does not match DEM input cell size

As my first post I offer a humble apology if this is such a basic question as to make any of you cringe. I feel like I have exhausted my search skills and read through the QGIS documentation ...
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37 views

Delineating sub-basin

Could you please help with delineation of sub-basin from SRTM DEM? From this DEM I've already delineated basin using hydrology tools in ArcGIS 10.0. Now as my study area is a sub basin within this ...
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25 views

What information, Open Attribute table of stream segment shows?

I have delineated the watershed from DEM data. I have converted the stream segment(raster) to vector lines. In the attribute table of this vector lines, there are 3 columns, CAT, VALUE, LABEL, what ...
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132 views

Problems using GRASS GUI (d.rast and r.watershed)

Update#2: I tried the command in the function list above instead in command console, and I got this in command output: and it displayed nothing, showing the same error message in the command ...
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41 views

Can you create a layer containing years of daily data, then extracting a specific area and time frame

So I have a tone of .nc files containing gridded rainfall and precipitation data in daily time steps. The data spans from 1980 to 2005 for all of Ireland. Now what I am hoping to be able to do is to ...