Questions tagged [watershed]

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

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Watershed delineation taking into account lake/reservoir

My watershed has several big lakes. When I delineated my watershed, I had some unwanted subwatersheds and river segments inside the lakes (see fig. below). I want to tell ArcGIS/ArcHydro to delineate ...
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1answer
38 views

GRASS GIS change raster output size?

I have a large inut raster geotiff map of size 12000x9000. I am running r.watershed to output a stream raster map. However it is much lower resolution, only about 960x711. How do I make GRASS GIS / r....
0
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2answers
43 views

Why no need for “fill-sinks” when using r.watershed in GRASS QGIS?

I've seen a few places that when using the r.watershed function in GRASS QGIS, you do not need to use the "fill-sinks" procedure on the DEM before running the function. According to the ...
2
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1answer
1k views

Is there a SWAT model integration for 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 ...
0
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1answer
706 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 ...
0
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1answer
19 views

How can I export a Seed Points layer as a image?

I have the Seed Points layer produced by Watershed Segmentation. I want to export is as a image (with background). How can I do this? I understand that I can do Project->Export->Export Map to Image. ...
1
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1answer
1k views

DEM reconditioning?

I'm using ArcGIS Desktop 10.5 Arc Hydro Toolbox & encountered a problem while trying to delineate watersheds respectively drainage lines. The red lines indicate my obtained drainage lines, which ...
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2answers
181 views

Why does running the SAGA Upslope Area tool in QGIS result in a 0 (zero) to 0 (zero) histogram and an all black layer?

I am using QGIS in order to delineate a watershed, and am using 1/3 arcsecond DEMs. I have created a Filled DEM using the SAGA Fill Sinks xxl (Wang & Liu) tool. Next I ran the SAGA Channels and ...
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0answers
22 views

Delineate watershed area for detention ponds

My study area has a series of small detention 'ponds' in the corner of fields. These are designed to capture runoff from the upslope contributing area (not from a discrete channel) during rainfall ...
0
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1answer
31 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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0answers
29 views

TauDEM: Missing cell area contribution

I have a terrain, that looks like the below: The geotiff file can be found here I run the geotiff file with the taudem, with the threshold value =10 1. PitRemove.exe Site6.tif 2. D8FlowDir.exe -p ...
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1answer
35 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 ...
1
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0answers
32 views

How to train or calibrate stream flow accumulation using observation data?

I need to calculate flowrate at designated coordinates (Point of interest - POI) in a watershed. I have real-world data from stream gauge stations along this watershed for each 50-150 km2 rainfall ...
2
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1answer
546 views

Watershed Delineation Loop - r.water.outlet resulting in NAN area while snapped

I am attempting to create multiple watershed delineations for stations within a CSV file. I have files for flow direction (raster with a cell size of 30m), flow accumulation(raster with a cell size of ...
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0answers
105 views

Watershed delineation using hydrological Python library

We would like to delineate watershed polygon for a given pour point using hydrological Python library. Until now, we have tried these libraries: pyshed Grass (r.watershed) Whitetoolbox We have ...
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0answers
10 views

How to improve “reach” in Watershed Segmentation?

How to improve "reach" in Watershed Segmentation? That is, I have a CHM (canopy height model) or similar image with objects that I want to cluster. Depending on contrast (?), the watershed ...
0
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0answers
8 views

How can I improve (Marker-Based) Water Segmentation results?

How can I improve (Marker-Based) Water Segmentation results? I've tried the ordinary Watershed first, then Marker-Based in ImageJ. While the Marker-Based seems like it could perform better, the ...
1
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1answer
41 views

Is it possible to create specific-sized watershed in a GIS environment? [closed]

I used the GRASS gis module to design catchment area with a minimum size of 2 kmsq. However, I would like to know if, in addition to the minimum size, I can limit a maximum size of 5 kmsq for them. In ...
3
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1answer
1k views

Interpolate raster data using computer vision (OpenCV)

Background A raster file collected via LiDAR records the topography of a watershed. To properly model the watershed, the river must appear continuous without any breaks or interruptions. The roads in ...
2
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1answer
152 views

Improve Catchment polygon processing result accuracy?

I use the ArcHydro Toolbox and ArcGIS 10.4 I ran through the regular steps of Filling Sinks of a DEM, Flow Direction, Flow Accumulation, Stream Definition, Stream segmentation, catchment grid ...
1
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1answer
34 views

Seeking quarternary watershed map of Eastern Ontario?

I am looking for a quarternary watershed map of Eastern Ontario. Where is the best place to look for this? I am currently using the ArcGIS Online basemap software to create my maps. I have a CSV ...
0
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0answers
13 views

Stream Segmentation resulting in a grid of squares

I have been trying to run the Arc Hydro Stream Segmentation tool for the purposes of delineating catchment areas and watersheds for a wetland analysis in ArcMap 10.7. I have thoroughly read the Arc ...
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0answers
37 views

Watershed Delineation for Specified Streams

I have a set of streams (currently a shapefile (line)) which I need to delineate the watersheds for. I have attempted to use various QGIS tools, however, each tool I have tried is for delineation of ...
5
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1answer
1k views

Get drainage basin of a polygon (with QGIS, GRASS or other FOSS)

Using a polygon shapefile and a raster DEM, I'd like to find a way to get the drainage basin of a polygon area — that is, the area of all cells which drain into or through the cells contained in the ...
2
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1answer
194 views

Individual tree segmentation using R-package lidR [closed]

I have some questions about individual tree segmentation in lidR. I'm looking at using the function lastrees with algorithm watershed. My first question is how to apply it for large areas. How big ...
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0answers
18 views

Scale national economic data down to a watershed

Economic Input Output databases such as e.g. the World Input-Output Database by the European Commission contain economic (and often environmental) statistics. The spatial resolution of data provided ...
7
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0answers
253 views

Accessing watershed boundary for lakes in R

I have had success accessing unique database IDs and polygons for various lakes in the US. I'm now looking to get polygons for the watersheds associated with these lakes, but have stumbled a bit. ...
1
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2answers
368 views

How to calculate area of the output of r.water.outlet?

I wrote the following code to use r.water.outlet module in GRASS GIS: import os import sys #set up GRASS environment variables sys.path.append(os.path.join(os.environ['GISBASE'], 'etc', 'python')) ...
3
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0answers
54 views

What is the complexity (big / little o) of the ArcGIS watershed delineation algorithm? [closed]

I'm curious about the complexity, in terms of Big or little O notation, of watershed delineation algorithms that are implemented in ArcGIS. I imagine that these will be dependent on either the size ...
2
votes
0answers
625 views

Delineating watershed using ArcGIS Spatial Analyst [closed]

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 reconditioning; ...
1
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1answer
57 views

Delineating small scale / subwatersheds using ArcGIS Desktop

I have a number of data points showing the placement of stream gauges. What I'd like to do is to delineate the subwatershed for each point, so that when rainfall events occur, I can see the drainage ...
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0answers
96 views

Fixing Discontinuous Stream Networks using ArcMap

I am currently working on a project in ArcMap 10.6.1 involving urban sewershed delineation, however, I am stuck with a discontinuous stream network. I took a LiDAR DEM from NOAA and subjected it to ...
2
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0answers
17 views

Variations in the number of Sub-Watersheds delineated by various tools [closed]

I have demarcated sub-watersheds using different tools like ArcHydro, ArcSWAT, and Hydrology tool (ArcGIS). The same input data have been used in all tools. There are 35 watersheds derived using ...
2
votes
0answers
883 views

Watershed Segmentation in SAGA-GIS [closed]

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 ...
2
votes
1answer
457 views

Calculating 3D surface area base on slope in ArcGIS Desktop? [duplicate]

How can I calculate 3D surface area base on slope in GIS for each morphological units in watershed?
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0answers
477 views

Why do I get an error running Catchment Polygon Processing?

I am trying to run catchment polygon processing in ArcGIS 10.3, and this is what i get "error hresult e_fail has been returned from a call to a com component" Can you help me to debug this error?
7
votes
1answer
257 views

Rockfall analysis (Nearest neighbor downhill) in QGIS

I am working on a rockfall guide for QGIS and I'm currently stuck on one of the stages. I currently at a point in the guide where I have two point layers one "rockfall release point"-layer and "...
1
vote
1answer
177 views

Managing large number of catchments/watersheds?

Does anyone know of an easy way to manage a large number (10,000's) of catchments/watersheds? I have defined a stream network and for each segment, I have a corresponding catchment (in a unique ...
2
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0answers
900 views

Watersheds and Catchment delineation in Earth Engine only with included datasets

Is there a possibility to derive Watershed boundaries or catchment areas by using one or more of the integrated data sets in google earth engine? The available data sets are: WWF HydroSHEDS ...
1
vote
1answer
920 views

Google Earth Engine, how to distinguish between rivers/streams and ponds/lakes in a water mask

I am trying to pull out every lake and pond in a region of SW Alaska. I have successfully identified all water features using the following code: // study area var rect = ee.Geometry.Rectangle([-168, ...
1
vote
1answer
248 views

Large Scale Watershed Delineation

Using QGIS,I attempted Africa's watershed delineation taking the following steps: Downloaded DEM from earthexplorer USGS (GTOPO30) Created a mosaic of the downloaded DEM Reprojected the mosaic ...
0
votes
1answer
139 views

Calculating distance between points following flow direction on ArcMap?

I delineated flow directions in a watershed on ArcMap (10m DEM). Then I want to calculate distance between two points 'following' the flow direction in each raster cell, not a straight line distance. ...
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0answers
65 views
1
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0answers
34 views

What does the values of Watershed Accumulation, Basin, In QGIS indicates?

While performing watershed module in QGIS each output gives some value range while changing color palette. what does it actually means in accumulation , basin, stream flow. What does the value ...
0
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0answers
53 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 ...
1
vote
1answer
60 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 ...
2
votes
0answers
573 views

Getting huge range of values when using Flow Accumulation tool in ArcGIS Desktop?

I'm trying to use ArcGIS Desktop to delineate watersheds for a series of sampling sites. I've been following the protocol laid out by WhiteboxDev in General steps to create watershed boundary in ...
3
votes
1answer
92 views

Watershed a catalog RasterStack in place of RasterLayer in lidR?

I want to use watershed with lidR package on a catalog. I paste this command: rep <- "/home/lasfiles" new_ctg <- catalog(rep) lidR:::catalog_laxindex(new_ctg) opt_output_files(new_ctg) <- ...
2
votes
0answers
72 views

Why difference in delineation of watershed by two online watershed modeling tools?

I am using two online watershed delineation tools- eRAMs and Model My Watershed (MMW)- to auto delineate watersheds using water quality monitoring sondes as my outlet points. I have three pieces of ...
3
votes
1answer
204 views

Tolerance setting in watershed segmentation(EBimage/lidR) in R

Can anyone here explain to me what the "tol" parameter in the watershed algorithm implemented in the BioConductor package EBImage (and lidR) does? I find the explanation in the EBImage help difficult ...