Questions tagged [rivers]
A river is a flowing body of water
119
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How to extract contour lines from bathymetry profiles (mainly cross sections)
I need to extract contour lines from surveyed bathymetry profiles.
The profiles are .csv files with multiple points and X, Y and Z coordinates. There are cross sections and a single longitudinal ...
- 142
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1
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74
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Adjusting flow direction of river based on DEM in QGIS
I have a huge vector layer as a line, that represents the river. The problem is that the flow direction is sometimes wrong (goes uphill). But I can't correct that manually, cause the layer is too big.
...
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How to apply "where" condition for an image collection
I am trying to create annual wetted channel for multiple years which I have to do 3 noise removal steps after calculating MNDWI. But I realized that there is an error in the second step (minSize line ...
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Using GSI waterline data for mapping Japanese rivers
I am using the GSI waterlines layer as a basis for mapping rivers in Japan (from here: https://fgd.gsi.go.jp/download/, click box labeled basic items). Does anyone know how to delineate just the ...
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QGIS Tapered rivers for entire landmass
I have a huge river network on my hands (see screen capture below), and would like to style its vector lines to get tapered rivers.
Some tutorials out there explain how to taper rivers (see links ...
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Why are my channels generating straight lines?
I'm having a rather horrible issue where my rivers decide to be straight lines instead of following the DEM I am using. Can someone explain why this is happening, and what I can do to solve this ...
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2
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45
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Showing historic path of river using ArcMap [closed]
I am trying to create something similar to the image below for Molonglo River in the ACT using ArcMap with several TIF tiles I have mosaicked together but no luck thus far.
Does anyone have any ...
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84
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Determining maximum capacity of river using HEC-RAS
Is there a practical way to determine the maximum hydraulic capacity of a river in HEC-RAS?
I would like to know for each cross section of my 1D model what the maximum flow rate will be before ...
- 1,114
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Bringing river bed to the same height as surrounding ground in QGIS
I have a DEM containing the current flow networks in an area. I also have a shapefile showing the same flow network. I would like to derive a new river network to see how water would flow if the ...
- 21
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1
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131
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Split seamless polygon representing river banks into separate polygons using center lines
I have a polygon that represents river banks. This polygon is seamless for all rivers. And I also have lines of each river. Here is the example of one situation:
Is there a way to split the seamless ...
- 53
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51
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Ordering points along rivers in ArcGIS
I have data on the location of water treatment facilities in the EU (green in the map) and of stations that control for water quality in rivers (blue in the map). I'd like to get a list of treatment ...
- 143
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Changing placement of label to be underneath curved line ArcMap Maplex label manger?
I'm working on a labeling rivers in an ArcMap project. For rivers but one the standard river placement works but I need a way to place the label of one river below the river not above like the ...
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253
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Calculating area in QGIS, defined as zone with relative elevation compared to a river
I’m trying to do the following in QGIS. When creating a 3D map, I want to follow a line or area of interest, such as a river, and create an area which is measured perpendicular to the line of interest,...
- 33
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146
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Ordering points along river in QGIS
I found data on water treatment facilities in the EU (labelled in green on the map) and stations that control for water quality in rivers (labelled in black). I'd like to get a list of treatment ...
- 143
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Interpolated Line shows in EPSG:4326 but disappears in others
I'm trying to stylize rivers but it's impossible since Interpolated Line ("tapered line") shows only in EPSG:4326 but disappears in EPSG:3857 and EPSG:25835. I have no idea why is that.
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Does most topographic data come with Z Coordinates, and if so how do you put them in a QGIS map?
I am trying to create a map of the rivers in a large catchment. When I try to 'fill the sink', mine makes it as if the surface is flat. My rivers are just squiggly lines.
It doesn’t look like it has ...
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Adding multiple sources to geometric network using ArcMap
I am using ArcMap.
I would like to identify all points that are on a river within 10km downstream of a starting point. I have multiple starting points and would like to do this from each of them.
I ...
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ArcGIS Pro interpolation point data along a line (river depth)
I'm analyzing habitat suitability using river depth data. However, my data are pretty basic: point data of the water levels at measuring stations (so literally points, not cross sections).
First, I'm ...
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Working with the FlowDir in the national hydography dataset
In the National Hydrography Dataset there's a FlowDir field.
According to https://www.townofnewipswich.org/sites/g/files/vyhlif4766/f/uploads/dataset_dictionary.pdf the two possible values for FlowDir ...
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Calculating distance between points within river network using ArcGIS Pro
I have a shapefile of a river, and the coordinates of several points. I am interested in calculating the pairwise distance between each of those points along the river network.
Is there any way to do ...
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Error message while running Strahler order for river delineation
I wanted to make river network using Strahler order in SAGA with filled DEM as the input, but there is an error message keep appearing:
QGIS version: 3.14.0-Pi
QGIS code revision: 9f7028fd23
Qt ...
- 51
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1
answer
614
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Rendering raster with fine structure at low resolution in QGIS
I have a raster showing a map with a lot of fine-scale structure (water depths and rivers) in QGIS, and I'd like to make the structure visible when the plot is low resolution.
Up close, I have ...
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167
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An application for measuring river length?
I'm aware of the coastline paradox and its application to rivers in that the measured length of a river depends on the resolution of the measurement.
Is there an application that calculates the centre ...
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Detecting automatically where rivers flow, directly into the sea or into another river
I am using this dataset of rivers in France. I'd like to automatically distinguish between rivers flowing directly into the sea versus rivers that flow into another river and draw a map of only those ...
- 131
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109
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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 ...
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2
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193
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Buffering river but it came out as circle
I'm buffering a river using QGIS 3. I am using 30 meters for my buffer. My problem is the buffers came out as a circle, not following the lines.
This is what happens during my buffer
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399
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Finding rivers from GeoTIFF files with GDAL
I've grabbed a bunch of .tif-files (from http://dwtkns.com/srtm/) and I am trying to render it in 3D as terrain.
I've converted it to a 16-bit heightmap successfully but I am curious is there any way ...
- 175
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1
answer
767
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Converting River Channel Cross-Section Data to Bathymetry
I have multiple surveyed cross-sections of river channels and need to convert this data into 3D polylines (shapefile) for use in a hydraulic model. The cross-section data is typically supplied in &...
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37
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Looking for rivers data of South Italy
I am working on a twelfth-century description of South Italy (Calabria, Apulia and Campania) which describes rivers that are now dried up.
I am attempting to create maps which reflect the description ...
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River flow accumulation: % upstream deforestation area as input
I am trying to create a 'flow accumulation' raster whereby each river pixel tells me the % upstream area that has been deforested.
This screenshot shows the HydroSHEDS Flow Accumulation dataset. I ...
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Understanding DEM of difference results in ArcGIS Pro [closed]
I am looking at channel change in a river in the UK and am using three DTM rasters to observe change over time. One of the methods I am using is to simply minus one DTM from another.
I have got the ...
- 310
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140
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Counting upstream dams along river network in QGIS
I am working on QGIS. I have a river network where each segment is a line with ID from the upstream one (if any) and the downstream one (if any).
I also have information on:
location of dams
location ...
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122
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Help with Anita Graser's guide on making tapered rivers. River shapefile has "width" field but expression is not working
https://anitagraser.com/2017/04/17/better-river-styles-with-tapered-lines/
This is her expression
CASE
WHEN "GEW_GRKL" = '< 10 km2 Fluss' THEN 0.2
WHEN "GEW_GRKL" = '10 km2 Fluss' THEN 0.4
WHEN "...
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146
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Measure distance to coast along river
I have a dataset on rivers and a dataset on the location of dams. I want to calculate the distance from the dams to the river’s mouth at the coast along the river (not the shortest distance) for those ...
- 143
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Connecting river segments with R riverdist package
I have imported river courses from OpenStreetMap into QGIS in order to recreate the Rhine river system for analysis in R with the riverdist package.
In order to calculate distances between sampling ...
- 141
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ArcGIS Pro: Create polygons from outlines of unclosed lines
First a disclaimer: I have very little experience with ArcGIS, I usually use QGIS and only recently started using ArcGIS Pro.
I have a River dataset from the Natural Earth Site, then made its ...
- 51
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1
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119
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GRASS GIS: creating raster with a certain gradient and extent
Constraints
- Use only GRASS GIS
- Automated using pyGRASS
Input
DEM
River raster OR river as vector (both are computed)
gradient of the valley (as a float)
vector line with direction and magnitude ...
- 1,116
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Interactive tool for editing TIN data
I created TIN to generate DTM using Mass points from Lidar data and river data that I made from stereoplotting. TIN results show there are several locations where the river elevation floats. So I have ...
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558
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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 ...
- 95
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1
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590
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Removing bridges and dams from DEM
Is there anyway to alter elevation of DEM where there are bridges and dams for the flood routing of the River?
I have to calculate discharge of the River from ancient times so at that time there ...
3
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2
answers
634
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GRASS GIS: Computing center line of raster feature representing a river
My goal:
Convert a raster layer representing a river feature (see picture) to the center line of the river stored as a polyline feature.
Limitation:
The whole process has to be automated.
I can ...
- 1,116
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1
answer
336
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Forcing left to right order of cross section lines of river using QGIS
Based on "Generating a series of cross sections (profiles) along a line?" post, how can I force the cross-section lines to be created, thus collecting elevation data, from LEFT to RIGHT ...
- 109
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135
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Linearized map of rivers - what is this called? [closed]
I am looking for a "linearized overview" map (as in the figure below) of the Brahmaputra river. I don't know the exact name of this type of map. Do you have any suggestion on what I should look for, ...
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Determining distance to nearest location along stream network by each cell using GRASS?
I have a river network in raster and locations of many dams on the river.
In the image above, the BLUE point represent one random cell. Dam 1 is downstream to the cell.
I am looking to calculate ...
- 81
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1
answer
286
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Calculating Distance from Outlet to Dam(s) using ArcGIS Desktop?
I am trying to carry out what should be a relatively simple analysis of river network fragmentation by dams. Similar questions have been asked as:
Obtaining length of river upstream of points up to ...
- 665
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1
answer
404
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Simplifying stream network based on grid using QGIS?
I have a river network (blue line in the below image) and I need to simplify this based on a grid. I basically need to snap the river to the closest vertex or middle-of-side of the grid cell's bounds (...
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727
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Cartopy lakes and rivers are clipped
I'm trying to produce a map showing water bodies like oceans/rivers/lakes polygons for purposes of plotting vessel voyages using cartopy. Ultimately I'm looking to create a sea mesh grid using the ...
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126
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Calculating percentage (or length) of stream network that is multiple channel streams using ArcGIS Desktop?
I have a polyline stream network of all channels within a drainage basin (which is 1.1 million square km)
A number of the rivers in the basin alternate between single thread and multichannel (i.e. ...
- 1
3
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2
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251
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Select a specific line length after and before a point
As you can see from the attached image, I have a shapefile of river network (line) and a point shapefile (this one represents the middle point of transects carried out in the area). I'm trying to ...
1
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1
answer
489
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Rainfall-weighted flow accumulation
I am perfoming a geospatial process whereby I want to use the flow accumulation (as an input for discharge proxy) in calculating stream power. I am using ArcGIS 10.2
So far I have:
1. Valley/channel ...
