Questions tagged [slope]

Use this tag when asking questions related to slope analysis.

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32 views

Understanding Analyse > Slope function of QGIS

Playing around with QGIS I discovered the tool 'Analyse > Slope' and I wondered what it actually tells me. Is it an additional information to let's say contourlines, which already provide info on ...
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1answer
30 views

How does QGIS calculate slope?

There are several ways to calculate slope in qgis using a DEM layer, but how does it actually work? My results show pixels with a slope of 40°+, this seems like a lot (in my DEM, one pixel is 25*25 m)....
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23 views

Slope calculated with QGIS vs slope in GoogleMaps

I want to calculate the average slope in percent of a vector line in QGIS. I have a DEM layer, converted it to a slope layer and then I use the plugin Profile Tool to calculate the slope of the line. ...
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18 views

GDAL Slope function not working with SRTM DEM data?

I'm a QGIS rookie trying to generate slope data for research projects in South Africa. I've managed to download DEM data from Bing Aerial maps using the SRTM-downloader but cant get the GDAL slope ...
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16 views

Calling help for ArcPy function from within IDE

In IDLE (for Python v2.7.2 within my ESRI path), when I type: help(arcpy.gp.Slope_sa) I get: Help on function <lambda> in module arcpy.geoprocessing._base: <lambda> lambda *args which ...
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23 views

Statistical difference in DEM-height compared to a specific point(feature)

Recently I've been struggling when trying to compare surrounding points of a DEM to a specific one (a feature in my case. A castle to be precise). I want to find out how steep a slope in an area ...
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1answer
37 views

How to calculate average slope and compass point of polygons in QGIS (3.18)?

I am using QGIS to rank about 800 PV areas according to their potential. I have a vector (.shp) layer with certain areas in polygons (inc. attribute table, every polygon has it's own ID). Now I would ...
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49 views

Calculating slope between two points

I want to know slope value between two point with lat and long coordinates. I can also get DEM values at lat long location for both points. What should I do next in order to calculate slope?
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18 views

Slope calculation workflow on pixel level

I know I cam calculate slope values based on DEM raster but I want to know how slope is calculated on pixel level. What values are taken into account when calculating slope on one pixel? Can anybody ...
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1answer
69 views

Error 99999 All raster processes fail in ArcGIS

I'm using ArcMap 10.8.1 and wanted to e.g. do a slope calculation on a Digital Elevation Model. Now I´m getting Error 999999 which usually refers to a bug or some unexpected error. First I thought it´...
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50 views

Dynamic Slope Calculation on ArcGIS Online Web Application

I have a DEM raster layer in our own GIS portal. It is then included in a web map online from which a web application is created. I am looking for a way that would allow users to calculate slope by ...
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1answer
30 views

QGIS - Changing the length of Shortest_Line for CAD-like slope pattern?

I haven't found a tool/plugin that could do this, but I am almost there. Here is what I want to do: I want to create a slope like the ones from CAD programms, but I don't have and don't need a DEM. ...
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2answers
106 views

Determining homogenity of flatroofs based on digital surface model / slope layer using QGIS

For the city of Berlin I have a digital elevation model as a 1x1 raster dataset from what I counted the slopes and I have shapefile data containing the outlines of buildings. My goal is to find ...
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1answer
28 views

r.slope.aspect grass gis datum format on dx and dy analysis

I'm performing terrain analysis due to photovoltaic installation on QGIS with r.slope.aspect plugin. I'm interested in evaluate differently N-S slope and E-W slope based on the PV system I would ...
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1answer
91 views

Calculate slope/gradient along streams (lines) segments in R

I would like to calculate the slope for stream segments in R. The stream network has been derived from the DEM. I have split the stream segments into equal parts of 100m (or less) and I have the DEM (...
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1answer
64 views

Generating vector slope maps using GDAL

I have a DEM file that I created a slope map of using gdaldem slope. This works fine and if I view and colorize it, I can now see how steep a hill is but now I'd love to create a shapefile out of that....
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33 views

Exporting slope values from DEM-derived rasters to CSV from QGIS [closed]

I want to export the slope values with their corresponding latitude and longitude into a CSV file. There's a DEM of a region having an irregular shape (not square). I have to generate the slope rate ...
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47 views

Extracting Factors Causally Related to Landslides from DEMs (SRTM) [closed]

I have the SRTM dataset, and I've managed to write some python code to show elevation and slope heatmaps. The code runs fine, and the elevation data is reliable (I checked some points from the web), ...
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1answer
43 views

“Raster map not found” error using GRASS r.walk

I'm using GRASS' r.walk for the first time, and I'm trying calculate the best path between two different points. I have a DEM (from SRTM) and a slope map derived from that same DEM. Both are in the ...
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28 views

How to calculate the slope of my polygons using DEM

I downloaded elevation data (DEM) of my study area from NASA and I converted it to slope. How do I calculate the slope of each farm at my study area? I have a shapefile containing the polygons of the ...
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41 views

Implementing drainage ditch in QGIS

In QGIS, I am trying to simulate some measures against erosion. One measure would be to install a drainage ditch at a contour line, where the slope goes from e.g. >30% to <30%. What I've tried ...
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23 views

Creating SLOPE from .ERS file using ArcMap

Working with ArcGIS Desktop 10.8. I have a .ERS file, it is a georeferenced image and the pixel value is a sea depth value. The depth varies from 0 to -2600 m. I am trying to create a SLOPE (degree) ...
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23 views

How to calculate and store (ArcMap) slope on huge mosaic dataset?

I have a huge raster dataset stored in a geoDB (DHM with 2m resolution for all of Switzerland), uncompressed size ~75 GB. I want to use the ArcMap Slope tool (or another tool would also work) to ...
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142 views

Slope Analysis with Python

I am trying to perform a slope analysis using Python and GDAL. The DEMs have a CRS of EPSG:4269 which is NAD83 and a geographic coordinate system. Previous attempts to perform a slope analysis ...
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13 views

Changing size of window when calculating slope in ArcGIS Pro

I am running a focal statistic using a 2m resolution raster with a 8x8 window (so 16m x 16m) to calculate the "range" across my tile. I also want to do the same with slope but by default ...
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1answer
123 views

Calculating Slope from DEM in QGIS

I have a world DEM raster in QGIS in EPSG:4326 with elevation units in meters. I'm trying to get a raster of the slope of the terrain, and I'm doing so using the "Slope" tool under "...
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1answer
40 views

Getting slope from DEM.tif using Spatial Analyst

I have a DEM.tif file and I want to get the slope. I know I use the Slope tool from Spatial Analyst. But, I'm confused which output_measurement to choose from (i.e degrees or percent rise). Basically, ...
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1answer
66 views

Combine slope info with Landsat for classification in Google Earth Engine

I wanted to add slope data as a band to filtered Landsat data. I used ee.Image.cat to "merge" two images. I can see added band in a merged image, but when I perform the classification (which ...
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65 views

SAGA GIS getting 90 degree slope in the whole terrain

I´m studying a jungle area in Peru, and when I try to calculate the slope with the "Slope, Aspect, Curvature" tool from SAGA v7.7.0, I get that the whole terrain has a 90-degree slope. In ...
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34 views

Draw a new curve for each level curve with specific slope in QGIS

I´m new to QGIS due to a project I´m involved in. For this project we want to draw a new curve for each level curve, but with a 0.5% positive slope for the valleys and 0.5% negative slope for the ...
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47 views

QGIS Slope not working properly

I'm new in QGIS and I have been having an issue with it. The thing is that I'm trying to get the slope and relief of a zone. I have the contour lines, from that I created the DEM with 'Rasterize' > ...
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2answers
254 views

How to get the slope from an elevation raster in QGIS?

I need to extract the slope from an elevation raster in order to do a species distribution model. It should be quite straightforward, but I can't seem to get it to work. I am running QGIS 3.10 on a ...
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33 views

Slope shows strange grid texture

Being aware that there were already similar questions concerning the output of hillshade/slope layer with an unwanted grid texture, but still I m confused, so I hope someone can explain it. Working ...
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24 views

QGIS Slope Analysis produces strange values [duplicate]

I am performing a slope analysis (Raster>Analysis>Slope) of a US Geological Survey DEM. I am calculating the slope of a raster DEM saved as a TIF. I set up the slope analysis as per the picture ...
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7 views

Clipping and exporting sections of raster from multi-feature shapefile using ArcMap [duplicate]

I have a multi feature shapefile and a slope raster and I'm trying to export images (tif, png whatever) for each feature showing the feature boundary and the slope raster contained within it with a ...
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0answers
16 views

Using WCS DEM data for make slope and aspect maps in QGIS [duplicate]

I need to do several slope and aspect analyses (hundreds). Instead of downloading an ASCII for each location, I want to extract/clip the elevation data from wcs and do the analysis. This is the WCS ...
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1answer
35 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.) ...
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0answers
22 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 ...
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0answers
50 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 ...
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0answers
14 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.
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1answer
44 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 ...
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72 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://...
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1answer
52 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 ...
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1answer
71 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 ...
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18 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 ...
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0answers
18 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 ...
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0answers
86 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 ...
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1answer
117 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/...
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1answer
96 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 ...
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0answers
38 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 ...

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