Questions tagged [watershed]

Use this tag when asking a question about a watershed related to GIS environment.

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how can interior basins be modified in the r.watershed GRASS function?

This is a follow up question to How does "Minimum Size of Exterior Watershed Basin" work in r.watershed command in qgis 2.18.12? I understood that the threshold parameter is used to ...
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223 views

Creating catchments/basins around stream feature class using ArcGIS Desktop?

I have a reasonably accurate steam network for a watershed. This network includes the main channel, major forks, and tributaries. Each channel, fork, and tributary are individual records with single ...
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410 views

Understanding Drainage Density?

I have calculated drainage density for two watershed and need to make sense of the numbers. One watershed has a drainage density of 1.08 km/km2 (area=32 sq. km and total stream length=34.436 km). The ...
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342 views

Making rivers with higher Strahler/stream order wider in QGIS?

I have a river network and the Strahler order of all rivers in it. Now I would like to create a map similar to this one http://www.hydrosheds.org/, i.e. with rivers of a higher Strahler order being ...
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746 views

From DWG to Shapefile: How to extract the channels length of water courses?

I have a DWG file with the drainage system of a small town. I need to open it on ArcGIS and get the total length of the channels that are part of one of the watersheds in the city. When I convert the ...
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121 views

Combining small watershed in a better way

I used grassgis delineated watersheds in a large area. After vectorizing the watershed raster, I ended up with a lot of tiny watersheds. "Dissolve" did help a bit, but there are about 1200 ...
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406 views

Automatically calculate average slope of a street segment

I'd like to be able to automatically calculate the average slope of a street segment in ArcMap (start elev - end elev / length). My map looks something like this, with street centerlines in black and ...
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1k views

Arcgis 10.1 Archydro tools, converting RasterToPolygon How can I solve: ERROR 000732: Input Table:

I´m using arcgis 10.1 and Archydro tools. During the Catchment Polygon Processing, one of the steps used to define the watershed limits, I get the folowing error: Executing: CatchmentPolyProcessing ...
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128 views

Discrete waterpoints with GRASS [closed]

I've been working with GRASS GIS for about two months. I have to develop a method for the identification of target regions of small hydropower plants. Boundary conditions are a predetermined minimum ...
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56 views

Water Quality Data Acquisition Sources

I was wondering what sources are available, or if anyone has water quality data for the Great Lakes and specifically Lake Ontario? We are interested in mapping Phosphorus, Organic Matter, Nitrogen ...
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1answer
155 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? what ...
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86 views

Add a field to output feature of a geoprocessing tool?

I am running the Watershed tool and RasterToPolygon tool in a loop for a number of points: flowdir = "flow.tif" flowacc = "flowacc.tif" pnts = [arcpy.PointGeometry(arcpy.Point(x=0.0, y=0.0, ID = 12))...
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199 views

Generate subcatchment starting from a DTM [duplicate]

I would like to know if there is a plug-in in Quantum GIS, which can help me to generate subcatchments starting from a DTM.
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18 views

basin layer from r.water.outlet Tool has values but is not rendering anything

I'm trying to deliniate a watershed with QGIS and used this tutorial to do so https://geogeek.xyz/catchment-delineation-with-qgis.html 1) r.fill.dir to create depressionless DGM 2) use r.watershed ...
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Modeled quickflow data per pixel

community! I'm running a hydrological model called Seasonal Water Yield from InVEST, based on monthly precipitation rasters, monthly ET rasters, a land use raster and watershed shapefile. One of the ...
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47 views

Watershed delineation by using QGIS with ifsar dtm 5m resolution of grid

I had some problems during running the channel and drainage basin with an IFSAR DTM, 5m resolution. I followed these steps, according to the guidance from website of QGIS: I reprojected the DTM to ...
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1answer
33 views

Using GageWatershed Function in TauDEM?

I have a D8 flow direction raster made from with TauDEM's D8FlowDir method and a point vector with an attribute 'id' for each. For some reason when I use these two as input in the GageWatershed ...
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26 views

Getting gridded population to resolution of land cover?

I have a population data at census tracts level and an impervious land cover. Impervious land cover is of 30 m resolution and census tracts data stored as a vector. Is there any way that I can ...
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53 views

Using tool “minus” in height model?

I'm doing a lab and I'm trying to understand exactly why I'm using the tool "minus". I have a raster which I'm calling "heights". I also have two rasters with water surfaces and watercourse. I have ...
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62 views

Getting higher stream number for lower order stream in ArcGIS Desktop?

The fourth order stream is showing greater stream number then third order stream?
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1answer
509 views

How to create “AGREE Stream” for DEM Reconditioning in Arc Hydro tool?

I want to deliniate streams and watershed using SRTM DEM. for this I am using Arc Hydro tool. While performing DEM Reconditioning for DEM manipulation it asks AGREE Stream as a input. How to create ...
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27 views

Why a range in area for catchments even if stream definition is set at a single size?

Using ArcHydro, I set stream definition at 5000, 20x20 cells (approx. 50 acres). I placed points at origins of each subsequent stream with batch point generation tool. Then used batch watershed ...
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319 views

Cumulative delay function for rainfall-runoff modeling using TOPMODEL [closed]

I am trying to model rainfall-runoff using TOPMODEL in R. The TOPMODEL needs an input called "cumulative delay function". The R documentation says "Flow is routed through a delay function which ...
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473 views

Expression into the raster calculator to invert DEM

I've made a DEM from first pass LiDAR data which I want to invert and run watershed segmentation and basin delineation over in order to hopefully extract tree canopy outlines and heights - I'm newish ...