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Questions tagged [slope]

Use this tag when asking questions related to slope analysis.

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3 votes
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Calculation of the average slope of the tractor path through the forest

I am currently working on a project whose task is to determine the average slope (in % not in absolute value but with a positive or negative sign -> rise or fall) of tractor roads located in a ...
sttipa's user avatar
  • 197
1 vote
0 answers
23 views

ArcGIS Pro Slope Tool failing with Output measurement and Z factor parameter in C# [closed]

The code below with 3 parameters fails to run slope tool and get expected result. No error is shown. Just expected result doesn't come out. public SlopeTool(string inRaster, string outRasterName, ...
Shahadat Hossain's user avatar
1 vote
1 answer
65 views

LiDAR DTM slope slope analysis with a twist. Calculate elevation changes of at least 10 feet within horizontal distance of 25 feet

I have raster DTM image of LiDAR data, mapped to Washington state plane north (US survey feet), where each pixel represents an elevation value in feet. Generating a "slope map" which shows ...
Nick's user avatar
  • 21
1 vote
0 answers
70 views

Make a slope-aspect map and create a circular legend for it in QGIS

I'm working on Terrain analysis of my ROI and could compute aspect and slope separately. Although I found a fairly easy tutorial on how to make a slope-aspect raster, I want to know if it's possible ...
Amine MB's user avatar
0 votes
1 answer
36 views

Combine Slope and Aspect of a DEM for suitiable PV-Powerplants

I want to get areas for PV-Powerplants via QGIS. I used the solution under Filter for south pointing areas from a DEM for extraction of the areas which are not facing north (60-300°). But I need ...
BAE_23's user avatar
  • 677
0 votes
0 answers
54 views

Using DEFRA LiDAR dtm-1m to calculate slopes etc in QGIS

I have a shapefile of woodland polygons and want to calulate slope and slope orientation of the polygons. I am using the LiDAR Composite Digital Terrain Model (DTM) - 1m in QGIS. Available at: https://...
user197410's user avatar
0 votes
0 answers
101 views

QGIS Slope: Slope processing tools not working as expected using DEM

I have a NRCS 2M DEM Bare Earth file for which I have already successfully applied the Hillshade and Aspect tools in my QGIS v3.34.1 project (see below). Now I am attempting to determine slope using ...
Linus's user avatar
  • 31
2 votes
0 answers
92 views

Calculating dredged material volume with sloped trapezoidal geometry using bathymetric data in QGIS

I have bathymetric data (as a point layer) for an area slated for dredging, where the target depth is -4m relative to Chart Datum. I have a polygon outlining the dredged area. The post-dredging ...
icru's user avatar
  • 21
0 votes
1 answer
80 views

QGIS and percent values in slope map

I create a slope map from a DEM downloaded with SRTM Downloader in QGIS 3.32.0-Lima. I searched in the internet trying to find the way to interpret the values of the left column in percent. For ...
Joseph's user avatar
  • 9
0 votes
0 answers
75 views

Cross-slope of a trail in ArcGIS Pro

I am trying to make an accessible map that includes the typical and maximum slope and the typical and maximum cross slope. I understand how to determine the elevation profile of the trail, but it is ...
Deb Innes's user avatar
2 votes
1 answer
178 views

Generate shortest straight path between points and a given elevation in QGIS

I'm trying to do terrain analysis in QGIS. I have a vector layer with equally spaced points along a slope, and these points are somewhat parallel to the coastline of a fjord: I'm interested in ...
Will's user avatar
  • 23
0 votes
0 answers
160 views

How to interpret values of elevation standard deviation statistic (and not elevation mean) from DEM

I am trying to interpret the standard deviation of elevation to understand the topographic landform of my study area. We have 2km*2km grids in the study area for which we extracted certain landscape ...
RashmiSRana's user avatar
0 votes
0 answers
58 views

Adding slope to lines drawn using PyQGIS

I want to add a slope to lines drawn using PyQGIS. The lines drawn with PyQGIS are currently green, but I want them to appear brown. How can I achieve this? The code I wrote: import math from qgis....
BrsDltV's user avatar
0 votes
0 answers
34 views

Identical values of bathymetric data

I downloaded gridded bathymetric data from GEBCO, from which I calculated a slope map using QGIS and then examined the resulting values using the 'raster layer unique values report' function. I found ...
br0wnb4n4n4's user avatar
0 votes
0 answers
66 views

QGIS Least Cost Path Analysis taking forever

I have been trying to calculate the Least Cost Path (LCP) between two points on my map. These points are approximately 100km apart. I have created a slope from my DEM raster, created proper vector ...
Brittany's user avatar
0 votes
1 answer
302 views

3D surface area with Google Earth Engine

I have my region of interest as a polygon. When I calculate the surface area I get a '2D value' (ie as if it was a flat surface). The problem is, the region is quite full of hills, so the real surface ...
terauser's user avatar
0 votes
0 answers
60 views

What is the hatch marking of my produced terrain slope raster?

I’ve been piecing together DEM raster data from different sources, in an attempt to create a terrain slope raster. I’m using ArcGIS Pro to merge the DEM’s together and then using the split raster tool ...
Whitney's user avatar
3 votes
1 answer
226 views

Getting x, y, slope in raster, using QGIS

I'm the new to QGIS. I have a slope raster that was made by using DEM 5m (also that was made by using contour 5m shp file). How do I get a txt(or csv ...) file containing [x, y, slope] data? I used '...
thisLecture's user avatar
0 votes
0 answers
63 views

QGIS how to export slope data with x, y

I have a shapefile with contour line data, that looks like the following: Columns 1, 2, 4, and 5 are geometric data and column 3 is contour data. (MultiLineString type) First, I tried 'TNI ...
thisLecture's user avatar
0 votes
0 answers
45 views

Units of slope output

I am calculating the slope from the DGM file which is of 1m spatial resolution. The default CRS is ETRS89 33N 25833 for that particular piece of land in Germany, kustriner vorland. In what units are ...
SUBHASHISH KAUSHIK's user avatar
0 votes
1 answer
470 views

Google Earth Engine - slope

I am trying to use the pre-built function of GEE for calculating the slope of the terrain, but I cannot really understand how the function works, since the documentation is also not really helpful. ...
Gaiagruu's user avatar
0 votes
2 answers
72 views

QGIS Report Slope Results

How could I report information about a raster result? In this case I have done slope analysis, and have reclassified it into 5 values for particular slopes. Now I am wondering if I can report ...
Jed C's user avatar
  • 1
2 votes
0 answers
83 views

Distort buffer on slope direction in QGIS [closed]

I'm an archaeologist and an average QGIS user, not advanced at all. I'm studying a method for the mountain archaeological contexts. My aim is to define some influence areas around the sites and ...
ugoposcolo's user avatar
2 votes
1 answer
128 views

Network analysis (with slopes)

Using the QGIS network analysis (layers) command, I can calculate the maximum areas that a "bus stop" point can serve by determining a distance X. However, I would like this distance to vary ...
Pedro Coelho's user avatar
3 votes
1 answer
356 views

What value does slope represent, how is it calculated from neighboring cells of a raster DEM?

In QGIS, I have a Digital Terrain Model. Using Slope (Menu Raster > Analysis > Slope..., in fact using GDAL Slope algorithm), I get an output raster, either in percents or degrees, the same ...
Babel's user avatar
  • 73.2k
3 votes
1 answer
414 views

Calculating slope using the 3*3 window approach for elevation data

I have some DEM grid data (25x25, 625 pixels) and I am trying to figure out the correct formula for calculating slope for each pixel. Some googling gave me a bunch of different formulas, but I've ...
frodolicious's user avatar
0 votes
1 answer
119 views

Determining slope percentage using ArcMap

I am working on a project where I need to conduct a MCA. One of the criteria is: if the slopes are greater than 15%, they should not be used at all. I have DEM model and a slope has been made in ...
Afnan Askar's user avatar
7 votes
2 answers
923 views

Drawing slope signature in QGIS

I would like to have a slope signature (in German "Böschungsschraffen") like this : https://bauforum.wirklichewelt.de/index.php?id=9672 (German) https://www.akgsoftware.de/docs/de/...
MartinMap's user avatar
  • 8,338
0 votes
1 answer
107 views

Building roads on steep slopes with QGIS [closed]

I work in forestry and want to get QGIS to generate a vector line that doesn´t exceed a certain road slope. I can get it to tell me what the slope is on a road I draw myself, but how can I just insert ...
Philip's user avatar
  • 1
1 vote
2 answers
277 views

Slope calculation with datasets in different CRS

I have a shapefile containing several zones. This file is in CRS EPSG:32644 (WGS 84 / UTM zone 44N). I have a DEM file (originally in CRS EPSG:4326 - WGS 84) that I converted to EGM08. The elevation ...
ParcoMolo's user avatar
1 vote
0 answers
193 views

How to calculate exact slope and aspect for a polygon

I want to calculate the aspect and slope for polygons, because they appear as fruit-growing areas. I got the DEM 1m for my datas and calculated aspect and slope with the QGIS functions. Then I ...
Micha's user avatar
  • 11
0 votes
1 answer
96 views

Getting watershed area corresponding to each erosion severity class for each slope class in ArcMap

I’m new to this. I have two (watershed) rasters: soil loss (erosion) by severity; and slope. For each erosion severity class (listed below), I would like to obtain the watershed area that falls under ...
Kevin Durant's user avatar
1 vote
1 answer
46 views

How to switch expression generated line sections in QGIS?

According to this thread about "Changing length of Shortest_Line for CAD-like slope pattern using QGIS" (https://gis.stackexchange.com/a/386104/212966) I would like to learn how to switch ...
pvosz's user avatar
  • 21
1 vote
0 answers
103 views

DEM to Slope in QGIS 3 [closed]

I'm having trouble with the slope of this particular DEM (USGS_13_n33w097_20211124). The file downloads correctly and presents the elevation values in QGIS, however after running the QGIS Slope tool, ...
greyhug's user avatar
  • 77
1 vote
0 answers
62 views

Slope Angle between vertices using QGIS

I am trying to work out whether a center pivot irrigator (you may have to google this to see what they look like) has too much angle between the spans as it goes over hilly terrain. I can generate ...
Luke Taylor's user avatar
1 vote
1 answer
172 views

Computing slope using QGIS

I want to compute the TWI (Topographic Wetness Index) for my study zone (SZ) using a DEM that I reduced to my SZ (SZ_DEM, https://www.mediafire.com/file/46vr8r4pbl2vpol/SZ_DEM.tif/file). The first ...
Germain Vital's user avatar
0 votes
1 answer
2k views

Average slope (in °) for each area

I have nationwide areas I want to get the average slope in ° in a south-north line for each area. I found something about zonal statistics in QGIS and DEM (enter link description here) but returns ...
BAE_23's user avatar
  • 677
0 votes
1 answer
151 views

Accuracy of LIDAR from XYZ and DEM comparison

I'm taking point cloud xyz's from LIDAR and turning them into DEMs, then comparing that DEM, to a DEM of the original 3D CAD Models to see how well the LIDAR is measuring the model for elevation and ...
Rudift's user avatar
  • 1
0 votes
1 answer
50 views

ASTER DEM, Incoherence of slope analysis

I'm using a Aster tile DEM to perform some terrain analysis on an area in the French alps (original CRS:EPSG 4326-wgs 84), using QGIS 3.2. My projected coordinate reference system is EPSG:2154-RGF93/...
Agnese Marcigliano's user avatar
0 votes
1 answer
25 views

Steep cropland selection using ArcMap

I have: a raster file of land cover classes, the classes are urban, bare land, forest and agricultural land. a have a DEM, from which I can calculate the slope classes. No I want to assign a new ...
Prayon's user avatar
  • 1
0 votes
0 answers
88 views

Creating slope map from DEM of Lunar South Pole

I've managed to create slope maps from other DEM's without much issue, but this DEM seems to have trouble and only does the very top section, with the rest being an error. I am very much a beginner in ...
Rudift's user avatar
  • 1
4 votes
1 answer
210 views

Number of pixels Elevation - Aspect - Slope

I have a DEM, resampled at 100 x 100 and clip by mask with a polygon. Unique values report give me Total pixel count: 733810 with NODATA pixel count: 427098. Aspect and Slope map give me the same ...
Kostas Pl.'s user avatar
1 vote
0 answers
44 views

Incorrect Z Value in Slope and hillshade Raster from QGIS

I have to create a TIFF for hillshade and Slope from data obtained by Eiva software, basically a XYZ file. When I drop in the XYZ or TIFF exported from Eiva and try to create the layers they seem ok ...
Andrew Laverty's user avatar
0 votes
0 answers
26 views

Changing labels and colors of slope map values in ArcPy with ArcMap

I have this code in ArcMap which produces a slope map with the correct values (the slope map is reclass.tif), but I want its labels that appear in the Table of Contents underneath it to show ...
Darell's user avatar
  • 45
1 vote
1 answer
114 views

Calculating terrain attributes before or after upscaling DEM

This is more of a theory question. I am working on a project that requires the use of topography data, I have a 1KM resolution global DEM to which I will be using GDAL to calculate general topography ...
JP Crossley's user avatar
2 votes
0 answers
42 views

ArcPy producing wrong slope map using Spatial Analyst with ArcMap

I wrote a Python script which is supposed to produce a slope map with 6 classes each one being from 0-3.99, 4-9.99, 10-15.99, 16-30.99, 31-60.99, 61+ (Although for testing purposes the max is 789.54). ...
Darell's user avatar
  • 45
0 votes
0 answers
272 views

DEM raster scale incorrect after running slope analysis QGIS

Working with DEM rasters from TNM 3DEP elevation data and trying to create a percentage slope map in QGIS. I added my rasters and tried running both the gdal slope that allows for % slope and the ...
user207315's user avatar
0 votes
0 answers
92 views

Getting percentage of parcels covered by slope polygon file using ArcGIS Pro without using Identity?

I've read the other similar stack questions and they weren't helpful, as in the processes didn't work or there was some ambiguous field references that may have contributed to my confusion and error. ...
Scott Jordan's user avatar
0 votes
0 answers
146 views

Negative slope in QGIS

How do I use the QGIS slope function to calculate slope and differentiate between uphill and downhill, and produce both positive and negative slopes?
Yishai Friedman's user avatar
1 vote
0 answers
194 views

Calculate slope along line feature for line segments of equal elevation?

I would like to calculate the surface slope of a glacier in the Swiss alps. In ArcGIS Pro this can be done using the Add Surface Information Tool. The output is a data table with the slope for each ...
Flexalo's user avatar
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