Questions tagged [topography]
The study and mapping of land surfaces, including relief (relative positions and elevations) and the position of natural and constructed features.
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Extract vegetation estimation Google Earth image
I am trying to extract an estimate of the percentage of vegetation cover from a Google Earth image from 2011, I downloaded the image and using QGIS I put it in the band that has the most contrast ...
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Confused about topographic data in base map using QGIS
I am getting started with QGIS and have some confusion about base maps and their data.
For example, say I start with the ESRI National Geographic USA Topo Maps as my base map (a new tile layer, using ...
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Creating sliced terrain from a TopoShaper generated Sketchup mesh, generated from ArcMap contours
One way to make terrain in Sketchup from contour lines is to use ArcMap to generate height contours, export them to Sketchup as .dwg files, then use the plugin TopoShaper to generate a terrain from ...
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Brightness Differences in DEM TIFF File
I created a DEM file with QGIS. File type TIFF. The files I use as sources are also TIFF. The file, which looks normal in QGIS, looks different when I look at it in other programs. When I open the DEM ...
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DEM < 10 Meters - Greece
I would like to know if there is any free or to buy option (site) from which I can buy/download a high resolution DEM for a small region in Greece. Except from USGS and OpenToography where the ...
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Land facet analyst- TP- 6 position using ArcMap
I want to do it in ArcMap in Land Facet Corridor - Topographic position index tools- Topographic position, 6 category, but I have this error:
Record Call Stack Sequence - Bottom line is error line.
...
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Topographic correction
I am trying to code the topographic correction and I get this error:
"Image (Error) Image.constant: Parameter 'value' is required."
I have seen a similar script for an entire collection, ...
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Extracting picture of certain elevation from ETOPO .tiff file
I started learning QGIS a week ago to do an alt-geo map and .tiff files from what I have read contain several image files displayed as 1.
Is there a way for me to export specifically the PNG that ...
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QGIS smooth mapzen DEM to create a very simplified topographic map
I am using Mapzen global terrain to create a topographic map.
How can I get a very simplified result like on the map of Greece?
Should I use contours lines ? And how to smooth them ? (wich algorithm ...
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Topo correction
How can I address the problems associated with the hills shadows in GEE, as shown in the screenshot attached? It brings a lot of complication.
AN IMAGE USED
// Filter to 2019 Landsat 8 images over ...
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Problem interpolating point shapefile QGIS
I've been having a lot of problems trying to interpolate some topographic point data from the coast of Japan. The data consist on regular separated points 10 meter apart. I've tried to interpolate ...
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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 ...
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How to create simple elevation map
I'm completely new to QGIS, and I would like to know if there is a quick way of creating an elevation map as in the following example. I would like to define 4-5 altitude intervals, and color them ...
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Estimate solar potential in Python with DEM
I am trying to calculate the solar potential/solar exposure of the littoral zones for a few lakes in Python. I already got the bathymetry/topographic data but I am still searching for ways to ...
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Trying to get topography via elevation package Python
So I'm trying to get some topography. In Detail some parts of the panama canal. I tried using the elevation python package. Here is my code so far:
import elevation
min_lat, max_lat = 8.0, 9.5
...
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Why is $length not giving me correct values?
I'm attempting to make a topographical map of Death Valley National Park, CA. I'm using EPSG:26911 and having an issue with filtering by length. In order to get rid of all of the tiny geometries that ...
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Merging overlapping features into one file with attributes (PostGIS)
I am working with os topography files which are split into points, lines and polygons. At the moment, I am trying to merge the separate files into a single topography file.
Using this source (Using ...
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Creating elevation profile from line feature, DEM and also polygon layer inside graph, using ArcGIS Pro
I´m new to ArcGIS Pro.
I have:
DEM,
Line feature (river) and
A vegetation vector layer (polygons).
I would like to make a profile from this line feature (the river), and if it is possible to show in ...
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Are the Sentinel-2 images in Google Earth Engine already topographically corrected?
I'd like to know if the Sentinel-2 Level-2A imagery, hosted in Google Earth Engine, was processed to attenuate topographic effects.
The dataset description page (https://developers.google.com/earth-...
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USGS Multiple Dates listed and I want to know what they mean
I want to take a look at a piece of land over time and evaluate the change in topography over time. I am using USGS to download some data and I realized they give you a list of dates that correspond ...
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Adding z dimensions to a Polygon
I have a polygon (vector file) which has a base z location from a raster file, however it is still a flat shape.
Is there a way I could add a z dimension to this vector file so it covers a 3-...
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Searching for waterfalls / water drops within an area of interest, return location and height [closed]
Is there a system/service for finding or searching waterfalls or "water drop" (say 1.5m drop)? Or is there another (simply) way to gain this data?
finding := Input a location and drop ...
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QGIS Print Layout doesn't show elevation labels
I'm trying to export a topographic map with elevation labels, but the Print Layout on QGIS is not showing the labels, only the lines. Why???
EDIT: I thought that was clear enough, but here are some ...
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Level curves in ArcGIS map - elevation - topography
I am using the ArcGIS web map and need to add a contour map (level curves for Uruguay) to perform a topography analysis. I have seen that in the ArcGIS Online search engine there are some maps of this ...
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Choosing Window Operator for 1-D Elevation Data
Have an interesting theoretical question here: Say you have a swath of elevation data that is essentially a line of densely spaced points. The data is noisy, so a simple median filter is something I ...
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Interpreting Ruggedness Index calculated from SRTM Tiles
I am looking for help interpreting the values from Ruggedness Index calculations.
I downloaded SRTM tiles using the SRTM Downloader plugin in QGIS. Then I calculated ruggedness from SRTM tiles in QGIS ...
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Identifiying the levels for streams derived from DEM
I am using GRASS GIS and I have been able to identify the various water-flow channels / streams using the documentation from r.watershed.
Now I wish to identify the levels of the streams. For example, ...
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GeoTIFF height map banding/terracing
I'm getting pretty bad banding, terracing, low resolution appearance when importing height maps to QGIS. I've searched the forums and haven't found a solution to this.
Attached are the original USGS (...
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Reproducing terrain ruggedness index from the original paper example [closed]
I am not able to reproduce the terrain ruggedness index for the example used in the original Riley et. al paper.
The example is as follows:
When I try to reproduce the numbers in MS Excel I get ...
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Where to find topographic basemap with no labels
I am new to QGIS and trying to find a simple topographical basemap for Britain and Ireland. It is a map of prehistoric sites, so I can't have any cities/streets/labels, just topography.
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Georeferencing historic airphotos along constantly-moving section of San Andreas fault?
I'm a geology graduate student working on a master's thesis project in which I'm measuring creep (movement) over time along a section of the San Andreas fault (in California, USA) using SfM derived ...
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Create a topography map base in QGIS
I am building an interactive web bike map and I would like three baselayers. Currently, I have an OpenStreetMap layer and I would like to add a topography layer. I am aiming for something shown on ...
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Elevation profile of earth [closed]
Where can I find elevation data for the entire earth so that for a given location (coordinate) on the earth, I can find out the elevation of that particular location?
In particular, I am curious, what ...
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Topography - represent result in WKT as polygons with rings or multipolygon without rings?
I'm new to GIS vector, especially for GIS tools like ArcGIS, QGIS,...
My question is, for this image below with poylgon 1 and polygon 2, typically how a WKT (Well-known text) is represented in GIS ...
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Topographic Correction Method for a Single Image SCS+C
I am trying to code the SCS+C topographic correction method for a single image and a I get this error: "Image (Error) Image.constant: Parameter 'value' is required."
I have seen a similar ...
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Summarizing flatness of county with statistic Elevation variance per square mile
I need to classify every county in the US as either hilly, moderately hilly, or flat. Accuracy is not critical, just a rough classification. I used R and followed the advice in this answer to import ...
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How could I classify every county in this US as flat, hilly, or moderate? [duplicate]
I'm looking for a VERY rough label for every county, so low-res data is fine here. Is there data on existing elevation change per county? Or should I get an elevation layer of the US and do a zonal ...
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How do we georeference a toposheet using GCS or PCS?
I am new to the GIS domain. I need to georeference a toposheet, Datum - WGS84, 1:50,000 scale map. I have done the georeferencing using WGS for GCP's and then projected to WGS_94_UTM Zone 43N, using ...
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How is Topographic Position Index calculated?
My understanding of how topographic position index is calculated is:
TPI = cell value - (mean of cell values within defined neighborhood)
But, I see that Weiss' original poster (http://www.jennessent....
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Sentinel-2 topographic artifacts: How to fix?
I'm working with Sentinel-2 (Level2A) false color composite images. A few of them present artifacts in alpine terrain. See highlighted area on the image below, in the Swiss Alps.
These artifacts are ...
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Raster not showing on Orthographic projection when zooming out
I am trying to put together Topographic .Tif rasters (from GMTED data) on an ortographic globe on Qgis 3.4.1, for exemple these 8 layers:
However when I change the projection and one of the various ...
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Adding elevation point data and lines to topography plot using ggplot2
I have pieced together some code to make a topography plot using elevation data and ggplot2.
However, now I would like to overlay onto this plot the country outlines, along with points to show the ...
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How do I assign a height to each individual contour line using QGIS. Raster > Extraction > Contour
What I'm essentially asking is, is there a way to, when making contour lines using extraction in QGIS, assign heights to each line? For example instead of 1000, 2000, 4000, 6000 etc. etc. you have 500,...
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Getting from a USGS historical topographic map to a Unity terrain heightmap
Is it possible to start from a USGS historical topographic map and get to a Unity terrain heightmap? To see an example of the kind of historical topo map I am talking about:
Go to: https://ngmdb....
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Why does no line appear when using Interpolate Line in ArcMap? [closed]
I'm attempting to make an elevation profile from a DEM in ArcMap using the Interpolate Line tool. I've done this before, and it has worked great--basically I just draw a line with Interpolate Line, ...
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Landsat L1GS product processing to change detection analysis ready state
At high latitude area of Svalbard Norway, one can find Landsat 8 data processed to L1TP level. With previous Landsat missions, this is not the case. Landsat 7 data are processed to L1Gt level and ...
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How to convert DHHN2016 to mean sea level?
I am new to GIS. How can I convert DHHN2016 to mean sea level?
I am using this dataset https://www.opengeodata.nrw.de/produkte/geobasis/hm/dgm1_xyz/dgm1_05314000_Bonn_EPSG4647_XYZ.zip which I stiched ...
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What happened to buildings on USGS topo maps?
I have been using the National Map website to download some topographic maps and I can't help noticing a big difference between the old and new. Historical USGS topographic maps have building outlines ...
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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 ...
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Effectively applying cpt-city colour ramps to elevation in QGIS3
There are lots of nice topography and bathymetry colour ramps provided by cpt-city in QGIS. However, I cannot find a straightforward way of specifying the transition from blue (below sea level) to ...
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