Questions tagged [hydrology]
The study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability.
264
questions
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0answers
18 views
Calculating drainage density
How can I calculate drainage density in QGIS if I have length for stream and grid line 1 km2? I need to calculate density per km2.
2
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0answers
25 views
Create catchments/subbasins for specific nodes
I have an XPSWMM model of a neighborhood storm drainage system. Nearly all of the drainage is above ground through a network of ditches and culverts.
I still need to create catchments for the ...
2
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0answers
39 views
Vector map (rivers) to Raster. [ **ERROR 1: Wrong value for -outsize parameter.**]
I want to transform this vector map:
To something like this
I only tried to convert the vector map through Raster> Conversion> Rasterize
But I get this Error:
QGIS version: 3.6.3-Noosa
QGIS code ...
1
vote
1answer
34 views
Quicker function than dissolve and difference
I'm on QGIS (v. 3.6) trying to create a map of Florida's hydrography using the NHD "Water Areas" shapefile. Methodology is to fix any invalid geometries in the NHD data, dissolve the layer, and then ...
1
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0answers
35 views
Extract longest flow path in ArcGIS pro
I did calculate Hydrology with Spatial Analysis tools==> Hydrology and now, I have streams and Watershed. In each watershed, I need to extract the longest Flow as a polyline for calculate slope. What ...
1
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0answers
80 views
SAGA: could not initialize data objects (QGIS 3.6, Mac 10.14)
I was trying to generate a catchment area from a DEM and got the error message:
The following layers were not correctly generated.<ul><li>/var/folders/ft/rbsnpzy96r76t8rkj5fdtzc40000gn/T/...
0
votes
0answers
22 views
Flow Distance Not Calculating for Entire Raster
I am trying to calculate the height above the nearest stream for an area. The problem is, it only does so for a portion ( the colored area below) of my area of interest. In the pic below, the black ...
2
votes
1answer
36 views
Creating symbols between connecting lines to represent line boundaries
I am trying to figure out a way to create markers as seen from the attached image where an angled line (in dark red) is created between the lines to represent a connecting stream. With the data I am ...
1
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0answers
14 views
Calculating SCS curve numbers using DSM instead of DTM
Are the curve numbers (calculated by SCS Curve number method) through DSM (Digital Surface Model) valid? Most of the SCS curve number studies focus on calculating curve numbers through a DTM (Digital ...
0
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0answers
29 views
Measuring relative discharge in QGIS?
I have marked several points on a stream (distant 500m) and then calculated each point elevation using a DEM data. On a stream there are two gauge station to measure the flow rate (discharge value).
...
1
vote
1answer
97 views
Finding glider reachable area / catchment area with custom slope?
I'd like to produce maps for gliders in mountains.
I'm looking to display the reachable area by a glider taking off from a given point (obviously with the corresponding DEM).
For a first approach I'...
0
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0answers
23 views
Install SWAT hydrological model on Ubuntu [duplicate]
I am trying to go back using Ubuntu in my work as hydrologist.
Is there any way to install the SWAT model, and in particular QSWAT on Ubuntu?
0
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0answers
53 views
Howerive vector stream network from a DEM using D-Infinity Flow Direction algorithm?
I have been working with a 1m LiDAR derived DEM to create a vector stream network. Using the D8 flow direction, D8 flow accumulation, and a specified threshold, I was able to create a vector stream ...
0
votes
1answer
26 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
1answer
37 views
How can I find the elevation a set distance upstream and downstream from a layer of crossing locations
I have a channel network which I've intersected with a proposed road network to produce crossing locations. I need to find the channel slope averaged over a 20m stream length.
I also have a raster ...
0
votes
1answer
36 views
Watershed layers that drain to ocean?
I have been searching for a watershed layer for California or for the entire US that encompasses all upstream area from ocean outlets (e.g. the entire catchment draining into each ocean output). I ...
0
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0answers
30 views
Is there a way to produce a line on a raster, which direction is based on cell values?
I am looking at a raster layer where each cell has one of 8 values, indicating where flow from the cell is directed. Is there a way to select any given cell, and have a line drawn which will follow ...
0
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0answers
40 views
Whitebox GAT branch depression big raster
I'm trying to run the tool Brunch depression form Whitebox GAT but the process doesn't work probably because the DEM is oversize
For generate that raster i converted the single quadrant in the ...
2
votes
0answers
36 views
Channel network from high resolution DEM for flat areas
I'm working on channel network extraction from a LiDAR DEM (square grid max resolution 0,25 cm), and my area of study is vary flat with some part below the sea level.
I applied the classical valley ...
2
votes
2answers
238 views
Fill sinks until a known value
I have a DEM and I want to fill every sink with a Value of 2 meter. If a sink is less than 2 meter, it is filled full and if it is bigger, it is filled until it reach 2 meter.
The problem is that ...
0
votes
1answer
36 views
GRASS Error: WARNING: segment zero_fill(): Unable to write (No space left on device)
I was trying to define the drainage patterns and to delineate some catchments based on a 30m DEM using
r.watershed --overwrite elev=DEM accumulation=Accum drainage=Drainage -m
but grass would ...
0
votes
1answer
79 views
Shifting entire river channel in HEC-RAS?
This question is specific to the HEC-RAS software.
I'm trying to use the software to shift a river channel. I've used the Geometric Data Editor for the Cross Sections to edit the positions of the ...
-1
votes
1answer
46 views
How can I reduce the size of shapefile (.prj, .shx, .shp) up to 8 MB? [closed]
It is sub basin photo which I want to upload to CHRS so that I can to download satellite precipitation data (https://i.stack.imgur.com/EQt3v.jpg)
2
votes
1answer
250 views
Choosing parameters for SAGA Wetness Index?
I've been working with SAGA GIS to calculate the Topographic Wetness Index of an alpine catchment. I am using the tool Terrain analysis > Hydrology > SAGA Wetness Index because, compared to ...
1
vote
2answers
155 views
Define catchment boundaries with GIS using R
Using a DEM, I want to define catchment boundaries for a given location on a river. Basically, what area drains into this point. In ArcMap, I can do that with flowacc and other tools; but I'd like to ...
1
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0answers
30 views
Split single polyline network at a point feature to make unique fields with unique distances
I am working with a large river network polyline shapefile. I am trying to calculate a dendritic connectivity index using a point shapefile representing locations.
The river network shapefile has a ...
0
votes
1answer
50 views
arcpy fails to get spatial reference in hydro script
I have an ArcPy script that extracts a stream network from any chunk of terrain. It takes the terrain and if it's in a GCS, it projects it to the correct UTM zone prior to further processing. Though ...
4
votes
1answer
105 views
Selecting or highlighting upstream elements
I would like to use the information from the Swedish SMHI related with their hydrological model elements (catchment areas) that have a Containment hierarchy structure, each element has the information ...
0
votes
1answer
221 views
tauDEM flow accumulation (D8 or D-infinity) results is NA-values for some major rivers
I am having some trouble with tauDEM that I am hoping someone can give me some advice on. I'm running tauDEM via command line through R-studio. I am working with some 30m resolution SRTM DEM data in ...
0
votes
1answer
502 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 ...
0
votes
1answer
68 views
How to Create SCS (now NRCS) Curve Number Grid using GIS with European map (ESDAC dataset)?
After finishing the watershed delineation, and after creating the HMS schematic in Arcmap, i was trying to include the land use map and soil map in the process, by using the CNgrid preparation by ...
0
votes
1answer
32 views
Choose between two points with same name but different attributes in ArcGIS
I have a dataset of thousands of points, made by the intersection of flowlines with waterbody polygons. Each polygon has two (or sometimes more, if the waterbody has multiple tributaries) points made ...
0
votes
1answer
94 views
Find minimum downstream flow distance from each polygon to any polygon in other feature class
The Problem:
I have two polygons feature classes, let's call them "SourceAreas" and "DangerAreas". For each SourceArea, I need to know if water could flow to any DangerArea and if so, what is the ...
1
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0answers
502 views
Displaying flow direction using arrow in ArcGIS Desktop?
I created a flow direction raster out of a DEM using ArcGIS Spatial Analyst Tools/ Hydrology, so the directions are coded in raster values as displayed below.
[http://desktop.arcgis.com/de/arcmap/10....
1
vote
0answers
36 views
Automatically locating endpoints (river sources) in a stream network
I have a stream network in ArcGIS 10.2.2 and I would like to know if it is possible to automatically add endpoints based on the stream network.
The network is pretty big and doing this manually ...
2
votes
1answer
73 views
Assigning land cover type (in shapefile) to hydrologic soil shapefile in QGIS?
I have a land cover and a hydrologic soil group shapefiles which cover my watershed. They have different polygons. For example, a forest type land cover (one polygon in land cover shapefile) may ...
1
vote
1answer
72 views
TauDEM Model Availability
I'm trying to find the TauDEM Model Builder Models toolbox.
I'm teaching myself how to use TauDEM to delineate watersheds. After running through some examples I started putting the modules together ...
1
vote
1answer
188 views
Flow accumulation algorithm open source code in C++ on Windows
I'm looking for flow accumulation open source implementation ( C++ or C# would do, Python no), on Windows, preferably the source code comes with Visual Studio project files so that I can just build ...
1
vote
0answers
64 views
Seeking open source alternative to RivEX (add-in for ArcGIS designed to process vector river networks) [closed]
I wish to process a river network - for the assessment of hydrological potential. RivEX is one addin (not free) which could be used with ArcGIS.
Is there any alternative to this?
1
vote
2answers
53 views
Acquire direction between points along route
How can I generate a directionality attribute between two points along a route/line?
Currently I am using Network Analyst to determine closest facilities, but I need a direction (upstream/downstream) ...
2
votes
1answer
57 views
Cumulative distance along a raster stream network
I am looking to calculate the cells along a stream network from starting points to a maximum distance and stopping points. I need something like r.cost in GRASS (https://grass.osgeo.org/grass75/...
3
votes
2answers
137 views
How can the flow accumulation in a hydrological model/stream network be maintained across tiles of a large area of interest?
My study area is too large to be processed in its entireity by any hydrological modelling software I have found yet. I will have to break it up in to smaller areas, but there will be flow across these ...
2
votes
1answer
224 views
Calculating floodplain for river section using DEM only in ArcGIS Desktop?
I'm looking to create areas where water might go when a river floods its banks. I have a pretty good resolution DEM (5ft^2 for each "square"). I'm not looking for anything super accurate or precise ...
8
votes
3answers
464 views
Locate wet patches using DEM
I'm searching for a way to determine the location of wet patches, after rainfall, in a DEM. By this, I mean puddles.
We are investigating the best locations to locate paths for recreational use. ...
1
vote
0answers
631 views
Qswat in newer version of QGIS
How can I setup QSWAT in newer versions of QGIS ? The link here says QSWAT requires QGIS 2.6. I tried installing QSWAT in new versions and it couldnot be done.
Is there a way to install QSWAT in new ...
0
votes
0answers
35 views
SAGA Maximum Flow Length problems with the Coordinate systems
I'm new to SAGA.
I've got a srtm data set from europe and want to charge the maximum flow length especially from the river Elbe. The data is in WGS84
So first I ran the tool "Fill Sinks"(Wang & ...
1
vote
2answers
125 views
Interpreting GLDAS 2.1 precipitation data
I am trying to use the GLDAS 2.1 3-hourly precipitation datasets available at:
The dataset is documented here:
https://hydro1.gesdisc.eosdis.nasa.gov/data/GLDAS/README_GLDAS2.pdf
The data is ...
1
vote
0answers
330 views
SAGA functions not writing output raster using QGIS 3? [closed]
I'm using QGIS 3.0, using a SRTM 1 Arc Second to perform hydrological analysis using some of SAGA functions (such as Fill Sinks), if I choose temporary output, it works fine; if I choose to save to ...
5
votes
2answers
183 views
Performing Weighted Flow Accumulation in GRASS?
I would like to calculate a weighted flow accumulation raster with GRASS. I have a DEM and a rainfall raster. I am looking to calculate the rainfall accumulated downstream. Basically, it is similar in ...
4
votes
1answer
148 views
Calculate Polygon Centerline with a LeastCostPath approach
I'm working on deriving the centerline of a polygon, similar to this question or this one, using a different approach. I'm 90% done with the task, but cannot reach the final step. My approach is to ...
