Questions tagged [slope]
Use this tag when asking questions related to slope analysis.
298
questions
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0answers
13 views
Why does the slope raster not align with the DEM?
I created a slope raster from a DEM raster using the Slope tool in ArcGIS 10.7 desktop. I snapped the slope raster to the DEM (but not the processing extent). The slope raster is the same projection ...
1
vote
1answer
25 views
Define point locations in relation to slope [closed]
I have a dataset of settlements that I would like to put in relation with slope and aspect layers that I have made to see if there is a preferred altitude or direction (facing north or south, etc.) ...
0
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0answers
12 views
Vegetation detection of anthropic crops with Google Earth Engine
I am very new using Google Engine and I need to know how to detect only agricultural crops on slopes without them mixing with that natural vegetation on hills. I have tried different indexes (like ...
1
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0answers
23 views
How to use QGIS Raster Calculator for computing slope?
I am using QGIS 3.10 in my Windows 10. I want to create a slope of a DEM layer. First I used "Slope" in the Raster Terrain Analysis. Then I used Raster calculator to find the slope less than 10. The ...
0
votes
0answers
10 views
Creating line profile graph in ArcGIS Desktop 10.6 with 3D Analyst for multiple line features
I'm looking to create profile graphs for approximately 150 streams in a 3D feature class. I made a sample profile graph but I'm not sure how to automate the process to run through the remaining lines.
1
vote
1answer
22 views
QGIS Rastercalculator: unexpected results for cos() function
I've calculated the slope values of a DEM and created a raster with values from 0 to 51,3 (degree). I wanted to calculate the Cos of these pixel values with the Raster calculator (to calculate in the ...
0
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0answers
23 views
How to remove slope from DEM to better visualise topographic features of vriver systems in QGIS
0
I have a DEM of a river channel that i would like to remove the overall slope but retain features such as pools, riffles, bars etc. I have used the River Bathymetry Toolkit (detrending tool https://...
0
votes
1answer
38 views
Empty result layer was created by raster calculator
I'm a new user of QGIS and learning some tips from this book https://www.amazon.com.au/Learn-QGIS-Andrew-Cutts/dp/1788997425. I'm currently practising how to use raster calculator to find areas at ...
0
votes
1answer
23 views
How to determine the individual slope values of GPS point features in ArcGIS Pro
I have created a geodatabase raster displaying the slope of a region's terrain and have a number of GPS points which I uploaded into ArcMap (using the GPX to features tool). The points are locations ...
0
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0answers
17 views
Altitude information for European highways
I need to calculate the gradient in major European highways. Fot this I need altitude data for each highway, let's say every 100 meters.
Are there such kind of data publicly available? If not, I am ...
0
votes
0answers
14 views
How to find all cells within a neighborhood with slopes towards the center?
I would like to iteratively go through each cell in a raster in arcGIS that meets criteria (already established as per below description) and find the percentage of cells in a several km neighborhood ...
0
votes
0answers
12 views
ARCGIS-Slope map with different X and Y cell resolution
I have a tif DEM with different resolution in X and Y :
cell size x =0.000222222222222222
cell size y=0.000111111111111111
with col=4501 and row =9001.
The resulting slope map that I have is a tif ...
0
votes
0answers
10 views
Modifying existing DSM from new slope raster layer for optimizing solar panel in solar radiation tools
I would like to calculate solar radiation of some building roofs using area solar radiation tools in ArcGIS Pro. However, I need to modify my DSM (input raster) because I want to optimize the panel ...
0
votes
0answers
43 views
Extract soil and slope data using coordinates
I have no experience at all in GIS and I'm trying to extract soil type and slope data.
All I have is a CSV file with latitude and longitude coordinates.
Is it possible to use this to extract the ...
1
vote
1answer
54 views
How to extract slope value for a geometry point in GEE
I want to extract slope values for various points in a certain region. Below is my current code which visualizes my region of interest on the map viewer
// dataset
var srtm = ee.Image('USGS/...
1
vote
1answer
41 views
Altitude point layer to slope heatmap in QGIS
I have a vector point layer (grid of 100km x 50km, a point every 20meters = 12.500.000 points). It has an altitude attribute.
I would like to have the information about the slope. I guess I need to ...
1
vote
0answers
20 views
Break of slope polyline from raster
I am looking to create polylines that define the break of slope along a cliff line.
Using LiDAR data I have created a slope raster using r.slope.aspect in QGIS. This nicely displays where the breaks ...
1
vote
0answers
98 views
Slope obtained with GDAL has weird lines
I am working with this DEM obtained using terraincache, it uses mapzen data. The SRC is WGS 84.
I ran this GDAL command to get the slope:
gdaldem slope -s 111120 dem.tif slope.tif (I had to do ...
0
votes
0answers
12 views
Highlight sparse pixels in a generated raster layer
I've been loving QGIS and need some expert help. I have a project where we need to highlight areas with slopes greater than a set number. I currently do this by processing the DSM with Slope and ...
1
vote
0answers
36 views
Slope and hillshade layer not continuous in QGIS
I have been trying to create slope and Hillshade rasters from a DEM raster, which is in UTM11N. I tried different ratios (vertical to horizontal) but everything is in meters so it should work fine. I ...
1
vote
0answers
36 views
Slope analysis in QGIS [duplicate]
I have a 1/3 arc-second DEM downloaded from USGS that I am trying to use to create a slope analysis layer.
The DEM is in ESPG 4269 to start and I've re-projected it into NAD83 UTM Zone 11N (the DEM ...
2
votes
1answer
34 views
QGIS Raster Mask Layer?
I have a raster slope layer and a raster aspect layer. The slope layer is single band grey, that is black to white, with white as the steepest slope. The aspect layer is pseudo colour.
I'd like to ...
1
vote
1answer
58 views
Identifying slopes surrounding a lake (in ArcGIS)
I'm working with ArcGIS 10.7 to investigate lakes in the mountains. I have created a 2km "hazard buffer" around every lake-TIN showing instable slopes (>40Ā°) above the lake surface from where a ...
0
votes
0answers
19 views
Incorrect slope values for points in QGIS [duplicate]
I'm trying to determine the slope of sampling points in QGIS 3.4, but the values are all ~89.99Ā°, which I know is incorrect. Pretty sure it's an issue when creating the slope raster.
Based on the ...
0
votes
0answers
31 views
Create a land-use raster in which the “crop cells” are distributed in dependency on the slope?
I have a geo-"scientifical" question. If you donāt know the answer, but have a hint how to search for the solution, this information would be helpful as well!
In Germany we do not get land-use data ...
0
votes
1answer
29 views
Seeing heights in Landsat 8
I have downloaded some DEM from Landsat 8 from usgs website.
when I opened the compressed file I saw some Tiff files and two text files.
I opened the txt file using ArcGIS 10.7 and it contains many ...
1
vote
1answer
29 views
Slope and side-slope of vineyard rows
I have a question about interpreting the slope and side-slope of vineyard rows using a line vector layer and a DEM.
I am trying to calculate the slope along the row (split into 2 meter lengths) as ...
3
votes
1answer
72 views
Obtaining slope and aspect for points in QGIS
I'm new to QGIS.
I have GPS points uploaded to QGIS and a ā
arc-second DEM (USGS) of the area. I'd like to generate slope and aspect data for each point.
What is the best way to do this?
The ...
2
votes
1answer
219 views
Technical documentation for GDAL Slope
I was running a gdal slope calculation on DEM I had
gdaldem slope B:/data.tif G:/slope.tif -of GTiff -b 1 -s 1.0
and I need to find the concert documentation on how the slope is calculated.
https://...
0
votes
0answers
16 views
Analyzing Sonoma County's topography/slope in 2017 fires
I am looking to create a map of sonoma county's topography. I am looking at one of the components of a fire: slope.
I want to first isolate sonoma county, which is easy enough to do, after that ...
4
votes
3answers
135 views
Using QGIS polygonize tool to create discreet slope polygons
I am trying to create a shapefile with polygons representing areas of different slopes. I am running into some problems using the following workflow.
I start with a digital elevation model and using ...
2
votes
0answers
67 views
Correcting slope of river bed on DEM using QGIS or ArcGIS
I have a DEM that has incorrect value of altitude/slope in the river bed area. This is a result of the interpolation of elevation value that are close to the river and creates lots of errors.
In fact ...
1
vote
0answers
27 views
Reclassify slope raster
I want to reclassify a slope raster as part of Least Cost Path Analysis, but I'm a little bit confused about the reclass rules.
My rules look like this at the moment (numbers left are degree):
0 ...
6
votes
1answer
416 views
Average Cross Slope Calculation
My county ( Pima, Arizona ) uses a number called āaverage cross slopeā which they define as
ACS = (I * L)/A
where
I = contour interval
L = length of contour lines in the area
A = area
...
2
votes
0answers
62 views
Slope and Aspect calculations giving wildly different results based on zoom using Leaflet
I asked Accessing slope and aspect data using Leaflet? last week about getting slope and aspect as a function of lat and lng in leaflet, and I am in the process of trying to code out a good answer. ...
3
votes
1answer
108 views
Accessing slope and aspect data using Leaflet?
I am building an application in leaflet, and I need to be able to access slope and aspect as a function of latitude and longitude. Currently I am able to get elevation data from the mapbox elevation ...
2
votes
0answers
86 views
QGIS Slope analysis thinks elevation unit is degrees making all slopes 90 degrees or 0 degrees [closed]
When i run my slope analysis the output has only two values: 0 and close to 90 degrees. The only way I have found to solve this is using a z factor of 1/111,120 which is the conversion of degrees to ...
-1
votes
1answer
62 views
How do I view and export table with slope data for raster and TIN?
Using an original point file, I created a DEM raster with IDW interpolation as well as a TIN. I used surface analysis to create 3D slope layers, one with degrees for the raster (IDW) and one with ...
0
votes
1answer
56 views
Comparing Slope among various DEM resolutions?
I'm comparing the slope products derived from DEMs of various spatial resolutions (1m, 10m, 30m) for a set area.
The trend I find is that as the resolution improves, the areal extent of various ...
2
votes
0answers
25 views
Correcting forestry acreages due to slope to get actual acreages treated [duplicate]
I came up with a process to get actual acreages vs map acres of steep slopes, but I am wondering what others do to correct for steep slopes and get actual acreage treated? For mine, In ArcGIS Desktop, ...
-1
votes
1answer
113 views
Calculating average slope using ArcGIS Pro?
I want to rate for ease of walkability for one track, I have a road shapefile and raster of the slope.
Any ideas about how to calculate average slope or other methods to do that?
0
votes
1answer
63 views
Which layer for least cost analysis?
I'm new to least cost analysis. I have a DEM-layer of a region and I want to know what's the least cost path from a to b. Do I have to use the DEM layer to calculate that? I also have a hillshade ...
1
vote
2answers
199 views
Labeling DEM or slope layer with slope angle in degrees?
I have a shapefile and made a DEM raster to create contours and slope analyze puttinggreen for a golf area . I have all i need except the slope values in degree (labeled directly in the map along with ...
1
vote
1answer
504 views
Digital Terrain Analysis - Roughness Index [closed]
Currently I am working on a project dealing with terrain analysis based on a DEM. I came across the term "roughness index" using slope values from that specific DEM. On YouTube I found a video, which ...
2
votes
0answers
55 views
Calculating variable buffers using slope between river and point 100' away using ArcGIS Pro?
I have a network of streams that I need to buffer based on a basic rule set. This buffer will depend on the slope.
The slope is determined by the looking at the difference in elevation between a ...
1
vote
0answers
95 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 ...
3
votes
1answer
233 views
GRASS GIS producing different slope than GDAL?
When producing a slope in GRASS GIS 7.4 the results are different than with QGIS (GDAL) and ArcMap for the same input data and same parameter (Z ratio is 1.0 and degrees). QGIS and ArcMap generate ...
2
votes
2answers
166 views
Adding slope values to attribute table (QGIS 3)
I have a DEM raster and some points (one .shp for all points) plotted on it.
I would like to know if there is a way to add the slope value of the pixel that each point is located in the attribute ...
-1
votes
1answer
229 views
Using QGIS 3.2 to add slope and/or % grade to county-wide street layer?
Using QGIS 3.2 what is the best way to add slope and/or % grade to a county-wide street layer using the following data:
Streets (polylines) = 35k records (10mb)
Contours (polylines) = 500k records (...
0
votes
0answers
85 views
Extracting slope of aspect information using QGIS?
In What is SOA (slope of aspect)? @Spacedman explained to me what SOA means. Now I need help to understand how I could work with it and extract the data that I want.
I want to use Qgis (with Grass ...
