Questions tagged [watershed]
Use this tag when asking a question about a watershed related to GIS environment.
193
questions
-1
votes
0answers
18 views
How to export selected pour points from a watershed raster into a point vector file in ArcGIS Desktop 10.1 [closed]
After having produced a watershed and executed a snap pour point on its output how can I export selected pour points values into a point vector file.
4
votes
0answers
72 views
Error while doing Watershed analysis using Python
I am trying to do watershed analysis using Python in jupyter notebook. Whenever I am passing commands regarding watershed delineation in Python I am getting output as raster matrix and when I am ...
0
votes
0answers
32 views
Finding a pour point in a polygon?
I have a polygon shapefile (created by someone else) that is a bunch of little watersheds. Unfortunately, it doesn't include any coordinates in the attribute table for the lat/long of the pour point ...
0
votes
0answers
45 views
Determining if species point data is upstream or downstream of artificial fish passes using ArcGIS Pro
I am working with ArcGIS Pro.
I am working on a project to determine how to prioritize restoration of artificial fish passes. I have been supplied with species point data, point data of the artificial ...
0
votes
0answers
13 views
Void fill is subsuming separate lakes into one
I would like to find the watersheds of several lakes that are very close.
When I use fill, a couple of the lakes fill into one.
Its important that these are separate watersheds. Many soil and snail ...
1
vote
1answer
46 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
votes
2answers
103 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 ...
0
votes
0answers
23 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 ...
1
vote
0answers
34 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 ...
1
vote
0answers
33 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 ...
0
votes
0answers
234 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 ...
0
votes
0answers
12 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
votes
0answers
9 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 ...
0
votes
1answer
23 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
vote
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 ...
1
vote
2answers
442 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 ...
0
votes
0answers
19 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 ...
1
vote
0answers
38 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 ...
2
votes
1answer
258 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 ...
0
votes
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 ...
8
votes
0answers
273 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
vote
1answer
66 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 ...
1
vote
0answers
101 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
votes
0answers
18 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 ...
-1
votes
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 ...
7
votes
1answer
274 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
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 ...
3
votes
0answers
55 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 ...
0
votes
1answer
180 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.
...
1
vote
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
votes
0answers
55 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
64 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
1k 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 ...
2
votes
0answers
78 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
99 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) <- ...
3
votes
1answer
240 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 ...
1
vote
0answers
45 views
Using minus in water drainage 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 ...
0
votes
0answers
81 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 ...
1
vote
1answer
755 views
DEM File “not found” Error when running r.watershed with Processing Toolbox in QGIS 3.4.2 with GRASS
I have downloaded a DEM from the NASA server with "SRTM Downloader".
I want to find the watershed area, so I run the "r.watershed" function form the Processing Toolbox.
However, I got a multi- "...
1
vote
0answers
44 views
Determining if Runoff Sinks drain to stream or drain to road?
I've tried using the linked method to determine area that drains to stream vs drains to road. For some reason when I run the watershed tool on the the raster representing stream and road features, I ...
0
votes
1answer
113 views
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 ...
0
votes
1answer
347 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 ...
0
votes
1answer
1k views
Watersheds in SAGA Fill Sinks Wang & Liu tool
I'm delineating some coastal subbasins using open source software. I have asked a similar question before (Delineating coastal subbasins using SAGA GIS or GRASS in QGIS?). I found that using SAGA Fill ...
1
vote
1answer
283 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 ...
2
votes
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 ...
1
vote
1answer
972 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, ...
0
votes
0answers
66 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?
0
votes
1answer
782 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 ...
1
vote
0answers
73 views
How to create an inlet drainage basin layer
Using a point layer of 8,375 inlets and a DEM, how do I create an inlet drainage basin layer with contiguous basins, each delineating water drainage for and into each inlet? I used an integer DEM, ...
2
votes
2answers
355 views
How to create “roof line” for a general polygon area?
I have a polygon with an arbitrary shape ( assume that it is well-formed with no self intersection, no duplicated points etc), and I need to subdivide the polygon into sub-polygons like how one would ...
