Questions tagged [watershed]

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

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53 views

Extracting the z-values of a stream in a watershed if I have the values of the contours

I have the z-values of the contours (physical contours) of a watershed in AutoCAD civil, but I may use them in ArcGIS 10.2 and I have already created a DEM. I need to extract the z-values for the ...
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1answer
584 views

Calculating average slope of a watershed upstream of many points in ArcGIS (upstream basin slope)

I am trying to replicate a procedure that the USGS Streamstats performs on points delineated along a stream network. They call it the "upstream basin slope" Basically, for a given point that I have ...
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1answer
418 views

Watershed analysis using GRASS GIS

I have Contour lines shapefile which I imported that into GRASS and converted to a DEM using the IDW interpolation technique (r.surf.idw with npoints 250). Now I want watershed analysis to be done ...
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2answers
233 views

Grass tools for watershed determination are not working well in QGIS

We have been using r.watershed QGIS-Grass tools for several months now without any problem, even with different QGIS versions. However, recently the tools are getting us results with a bigger pixel ...
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1answer
309 views

How to define pour points from a stream network at a barrier for watershed calculations?

I'm looking for a way to check if cells from one raster file have contact or get close to cells from a second raster file. For example the blue raster is a barrier and the coloured is the flow ...
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1answer
907 views

Watersheds tool does not create watersheds in ArcMap?

I`m trying to create watersheds and every time I run the Watershed tool, the result will be very interesting. I use snap raster and I set the extent of the output to the extent of the flow direction ...
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1answer
307 views

How to fix this “Sorry <1> is not a valid option” in GRASS-Ubuntu using r.water.outlet?

I am working with this .sh code (a while loop, extracted from: http://www.surfaces.co.il/) to create watersheds from drainage raster and outlet point of every watershed, but I obtain this error: "...
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1answer
602 views

Writing Variables Values into Feature Class Table in ArcGIS Modelbuilder

I am trying to use the ModelBuilder for my master thesis. What I want to do is: 1) Create two new fields in a watershed feature class (contains several watersheds) 2) Use the watershed feature to ...
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1answer
4k views

How to indicate flow of a watershed feature?

While tracing and digitizing rivers, streams, rivulets, etc., is it possible to indicate the direction/flow in the shapefile on QGIS? I'd like to avoid using map labels. Ideally, when done tracing, I ...
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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 ...
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1answer
440 views

Better ways to check if GRASS r.water.outlet works out fine output

I use my python script to call GRASS module r.water.outlet from outside, and here's my script(I perform this script in pyscripter): import os import sys #set up GRASS environment variables sys.path....
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1answer
475 views

What is the 'water retention capacity' tool and how is it used?

In the latest version of QGIS, I found a geoalgorithim in the processing toolbox that will generate 'water retention capacity.' I am familiar with DEM-based hydrologic modeling tools in QGIS, but I ...
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1answer
43 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
84 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 ...
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1answer
27 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 ...
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0answers
32 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 ...
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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 ...
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0answers
39 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 ...
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1answer
858 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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1answer
760 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, ...
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0answers
59 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, ...
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0answers
323 views

Creating sub-watershed within a basin

I am a beginner to QGIS. My problem is I tried to create sub-catchment within a basin by using provided point datasets (river gauge location). In total, I have 12 measuring points (i.e 12 pairs of x ...
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1answer
128 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 ...
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0answers
133 views

Sub-watershed boundary is partial overlap the admistrative boundary

I am using ArcMap 10.3 on a Windows x64 system. I would like to extract the sub-watershed for a particular area. The data I used was ASTER 30m DEM and a shapefile of my study site. The first step was ...
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0answers
68 views

Extracting watersheds at (arbitrary) pour points of waterways inconsistent with DEM

I am using ArcGIS 10.4.1. I am trying to extract watersheds for a number of random locations along a river network. These locations represent points where certain physio-chemical qualities of the ...
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0answers
103 views

Finding points of sudden large changes in stream gradient QGIS

In QGIS I am trying to divide a streams shapefile at points at where there are sudden large increases or decreases in gradient. For example at the red circle the gradient of the stream increases from ...
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0answers
63 views

Polygons merge/union using two colums values

I'm using HydroSHEDS watersheds shapefiles for a proyect. Watershed are delinated applying the rules of Pfafstetter codification. I need to merge/union the different polygons in a same shapefile. I ...
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0answers
120 views

What causes the striations in this slope map?

I have created this slope map using a 10m DEM from alabamaview.org and I just noticed it has small striations (zoom to see): What could cause this, and is it a big deal, or am I over-analyzing the ...
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0answers
228 views

Understanding Add Surface Info Tool (Average Slope) vs Slope Tool?

What is the difference between the values calculated using the slope tool vs the slope option in the add surface information tool? I am making a map that displays watershed slope (using the slope ...
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1answer
117 views

Using NLCD to quantify rate of urban sprawl in a watershed

I have downloaded five datasets and would like to quantify the rate of urban sprawl in a watershed from 2001 to 2011 using NLCD. Here is the data I have: (1) NLCD 2001 to 2011 Land Cover from to ...
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0answers
235 views

What channel initiation threshold value should I use when creating a stream network for drainage density calculation?

I need to calculate drainage density for two southern AL watersheds (D’Olive and Fly Creek). What channel initiation threshold value should I use when creating the stream network? I am following ...
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0answers
159 views

Error while using Watershed tool

I was trying to create watershed from a DEM that used polylines. So I converted that to raster and the raster to TIN. I delineated the TIN to fill the gaps and then returned it to raster. Then I got ...
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0answers
95 views

Adding curb/gutter and subsurface storm drain networks to watershed analysis in QGIS

I need to do a neighborhood scale drainage analysis. The analysis needs to accurately show the drainage area to each storm drain inlet. Using GRASS on QGIS 2.12.1 on OS X, I have been able to ...
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0answers
148 views

calculate flow accumulation in a river with two outlet points

I'm trying to calculate flow accumulation layer (with arcGIS) in a basin with 2 outlet points. I have used "dem reconditioning" tool to modify my dem according to a vector layer, which contains my ...
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0answers
70 views

Ideal minimal area for watershed automatic delineation using DEM SRTM

I need to do a bunch of analysis on a city using for that, watersheds . As smaller the watersheds are, better are quality of my work. Due to the vertical accuracy of SRTM DEM, I know there are some ...
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0answers
399 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?
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0answers
241 views

Riparian corridor delineation in QGIS

I am trying to delineate the riparian corridors using GRASS in R. But I am having some issues. So is there a plugin in QGIS using which I can extract riparian corridors using the already available ...
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0answers
49 views

grass r.watershed to larger rivers parallel lines to same stretch

I'm trying create stream channels with r.watershed grass64. However, it shows two or three parallel lines for the same stretch of river. The river is large in some parts, but is just one river. Does ...
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0answers
597 views

Combining Raster and Vector data

I've created a Watershed raster data set (using the Watershed Tool) for a certain area. Within that watershed raster, there are 8 basins that appear I'm trying add the total population to each of ...
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0answers
402 views

Simulate water runoff to get water height over each pixel of DEM

Here is my problem that I am trying to deal with. I have given a height map of around 512X512 resolution(It is Geo-referenced and I have the meta-data for this). And I have given that this area ...
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0answers
109 views

How to create a boundary vector of objects after using watershed_segmentation python

I used watershed segmentation in opencv-python to separate object. However, after segmentation I don't know how to create boundary polygons of objects (red rounded in the image attached).
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0answers
315 views

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

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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0answers
458 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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1answer
320 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- "...
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1answer
701 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 ...
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1answer
914 views

Efficient algorithms for recovering watershed boundaries?

This is somewhat related to a previous question I asked: What Algorithm is used by ArcGIS Watershed tool? I was wondering if there is a more efficient way to calculate catchment areas if you are ...
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2answers
651 views

Watershed layers with names for each one for Europe or Sweden?

I am working on freshwater species and I would like, make a list of each watersheds used for each species. So I am looking for a watershed maps which contain name of the watershed. I found some good ...
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1answer
143 views

How to calculate stream order in GRASS 7.0.2?

I would like to calculate Strahler's and other stream hierarchy from my input raster but I am not sure how. This manual suggests tat I should use r.stream.order command, however in version 7.0.2 "...
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1answer
1k views

Is there a method to create watershed on google earth?

I want to create a watershed boundary for a lake only using google earth without using other source of data like srtm etc. Since we get the height of the location can we use it somehow and create a ...
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1answer
569 views

import parameters for r.watershed - (watershed basin analysis program) tool from grass using Qgis 2.2

I want to run this tool from Qgis 2.2 but i don't know how to use the PARAMETERS to run this tool. The red frame are the PARAMETERS I don't know. Can someone to tell me what those PARAMETERS are and ...