Questions tagged [area]
Area is a quantity that expresses the extent of a two-dimensional surface or shape, or planar lamina, in the plane.
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Calculating area of water pixels, and plotting them in Google Earth Engine
I am trying to create a time series of the total area of water pixels in a particular region using the ee.Image.pixelArea() method. I understand that this method creates a raster whereby the value of ...
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1answer
32 views
QGIS - Inaccurate field calculator
When I retrace a polygon using the measure area tool and get what I believe to be an accurate area measurement. However if I utilise the field calculator within the attribute table to calculate the ...
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Extract common area from raster layer in QGIS
I have raster layers of satellite images (4 bands R,G,B and NIR) in GeoTIFF format. These images have been taken by a single satellite and consequent images have a small area of overlap between them. ...
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Earth Engine - Calculate area (km2) from geometry (multi-polygon)
First off, I am pretty new to Earth Engine, and no coding background. I am working on a historical land use change study and have uploaded an old air photo to Earth Engine (it has been orthorectified -...
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20 views
Calculate area within a buffer zone
I am working on 3.12.0-București.
I have created buffers (radius=300 meters) on a set of sampling points.
I do not remember the number of segments that I have used. However, I have set a high number ...
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1answer
22 views
Calculating the area of the polygon segments within multiple overlapping buffers
Let me try to explain my problem:
I have a layer of polygons
A layer of overlapping buffers
I want to calculate the area per buffer of the containing polygons.
The problem is that the buffers are ...
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19 views
My service area polygons are not right, look more like road buffers
I have included a screenshot of my settings and what one of the polygons looks like. I have this set to approximately 10, 20, and 30 mile service areas and this entire segment is only about five miles ...
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25 views
Getting broken up area of smaller polygon that overlaps two larger polygons using ArcMap
I am using ArcMap.
I have two polygons. One is precinct which there are around 45 and i have census tracts which there are around 1,0000.
I want to create total population within each precinct. Though ...
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22 views
Mapinfo Pro: .grid file area
I was wondering if anyone would help me on this: I have mapinfo pro and a raster .grd file that contains signals strength levels for different locations. All i want to do is to simply calculate the ...
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1answer
28 views
Problem getting correct area for polygon and choosing a CRS
Using GeoPandas and I'd like to calculate the areas for the geometries in my dataframe. I'm also doing other things like finding the area of overlapping regions of geometries from different ...
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1answer
26 views
Converting points with an associated circumference to a raster overlay
I have a data frame in r with x and y coordinates and each point has a circumference (tree_crown) around it. I'm wanting to build a raster file that each cell would have a value equal to the percent ...
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1answer
92 views
Computing area of raster cells with value “1” in QGIS?
I have two layers, a raster and a vector. The raster has values 0 and 1. The vector layer has an "Area" field for the total area of the shapefile/boundary. I want to compute the area covered of the ...
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1answer
22 views
How to calculate the area of each WRB soil class with the 2017 TAXNWRB_250m raster?
For my research I want to calculate the total area of each WRB soil class on each continent in km2 using the 250m WRB soilgrids raster. However, the total area I calculated is almost 1.3 times as ...
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21 views
Grouping of polygons or overlaying layers in same shapefile? Problems calculating the correct polygon areas
I am having trouble calculating polygon areas of my shapefile. When opening the shapefile in QGIS it seems like there are multiple polygons overlapping within the same shapefile or that polygon areas ...
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19 views
Finding overlapping area of vector and raster layers in QGIS
I'm working in QGIS with 3 different layers:
A raster layer indicating 0 for non-rice and 1 for rice area
A raster layer indication 0, 1, 2 for different hazard levels
A vector layer containing the ...
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15 views
openlayers 6: measure tool dosen't show up drawn shapes
I am working on a laravel project, where I need to insert a map in the interface of my application.
I am using openlayers V6.3.1 to create the map with its basic tools.
I still have a problem, measure ...
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0answers
30 views
Draw ellipse based on values within an attribute table
I would like to be able to draw and ellipse on a map based on values within an attributes table. At the moment I have 6 transects at a site with values based on IQI (Infaunal Quality Index) values; ...
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31 views
Calculate cross-section area in QGIS
Is there a way to calculate the area of a cross section (blue zone on the graph below)in QGIS without creating new layers ? Like a more complex version of the profile tool which would calculate this ...
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1answer
31 views
Account for cell size differences in WGS 84 rasters
My data
I downloaded climate data from the WorldClim website, provided as rasters at a global scale using WGS 84 and various resolutions. I'm using the 15min resolution and I focus on Mediterranean ...
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1answer
21 views
Getting $area from a feature in a processing script in QGIS3
I've created a complex process, but I'm stuck on one point.
I found this code to find the number of features in a layer.
def processAlgorithm(self, parameters, context, feedback):
...
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1answer
31 views
Is this transformation using square metres or kilometres (3857/32633)?
I am using geopandas to compute population per km2. However, I don't know if this transformation is using meters or kilometers.
gacs_df = gpd.GeoDataFrame(acs_df.merge(census_gdf2, on="geo_12", how="...
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17 views
Retrieve image from area
I'm looking for a way to retrieve an image (a satellite one, preferably) from a rectangular area of a map given a minimum and maximum latitude/longitude.
What tools can I use to achieve this?
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2answers
76 views
Calculate intersection area in square meters of two polygons that use EPSG:4326 in Python
I have EPSG:4326 data for polygons and would like to calculate the intersection of these polygons in square meters.
Is it possible to do this without any transformations from EPSG:4326 to some other ...
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1answer
98 views
Calculate area of polygons in square meters when CRS is EPSG:25833
I have EPSG:28533 coordinates and would like to calculate its area in square meters and then transform these coordinates to EPSG:3857. I have taken the code from here to calculate the area but it does ...
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1answer
36 views
How to use a specific AREA (km2) to create a buffer-like feature around a polygon (Area to Buffer)
How to create a buffer (or buffer-like feature) based on a specific area (in km2)?
I have a specific area (e.g. 14.5 km2) and would like to lay this area as a buffer (or something similar to a buffer)...
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1answer
33 views
How to calculate total area of all features of a class in ArcGIS without double counting overlaps
I have a polygon feature class with a field "Area" in the Attribute Table calculating the area of each features. Some features overlap each other. How can I calculate the total area of all the ...
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15 views
Service Area - Not taking into account of all network
I'm trying to work out an 800m service area from a station.
However, QGIS is not taking into account some of the network lines.
The yellow colour highlights the network that should be included in the ...
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1answer
37 views
How to create polygons with a set area in MapInfo?
I need to create polygons with set areas in MapInfo. There is a solution for QGIS in the form of the the QAD plugin but I can't find an equivalent tool for MapInfo.
The task I'm actually trying to do ...
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2answers
159 views
Mean of polygons area within another polygon layer
I have the following layers :
Sectors (polygons limited by the black lines)
Houses (polygons in light blue)
I have created the area attribute in the Houses table. I have also created an attribute ...
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1answer
77 views
Why does running the SAGA Upslope Area tool in QGIS result in a 0 (zero) to 0 (zero) histogram and an all black layer?
I am using QGIS in order to delineate a watershed, and am using 1/3 arcsecond DEMs. I have created a Filled DEM using the SAGA Fill Sinks xxl (Wang & Liu) tool. Next I ran the SAGA Channels and ...
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1answer
22 views
Dissolved area of polygons using the gArea function of rgeos?
I am taking occurrence point data (in the form of individual Lat/Long points), and adding a 1km buffer around them using gBuffer() in R package rgeos.
I'm then using the function gArea() to calculate ...
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1answer
31 views
Is it possible to add an extra Area Measure tool on qgis2web map?
Is it possible to add an extra Area Measure tool on qgis2web map? I am confused..
code is here.
exporting qgis2web map with openlayers completes with no error.. but with leaflet it ends with ...
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39 views
Add Area Measure Tool in qgis2web output map
I tried to add an Area Measuring Button parallel to the Distance Measuring Button to a map from qgis2web output.. but somehow it didn't trigger..
I put values off the Button id "Line" and "Polygon" ...
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25 views
Calculate 70% of the area inside a polygon based on the polygon centroid
I am trying to generate an area within a polygon based on the polygons centroid that covers 70% of the containing polygons area. I generated the polygon centroids as points but I do not know how to ...
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1answer
72 views
Calculate areas in ha (hectares) with gdal?
I would like to calculate using gdal certain areas in ha (hectares) for a reclassified raster. Can somebody help me with this?
Here is the reclassification:
#RBR reclassification to USGS burn ...
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1answer
271 views
Average radius of city size?
Do any geographers on here have an estimate of the mean and median city radius sizes? I'm trying to optimize some Google Places API queries [e.g.] and this information would be helpful for that ...
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33 views
Land parcel area inconsistencies in EPSG:4283 and/or ESRI:102171
I have parcel data from Landata, the agency that looks after land parcels in Victoria, Australia. I am finding a huge difference in the area calculated in QGIS for the parcel compared to onground ...
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1answer
123 views
Tool in QGIS to Get Area Weighted Average
I am looking for a tool that can give me an area-weighted average.
I have a shapefile of parcels and another shapefile with Curve Numbers. I want to get Area Weighted CN for each parcel. If I do it ...
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2answers
76 views
Plotting point every x m2 in polygon using QGIS plugin
I'm trying to work out whether its possible to plot a point every so often within a polygon.
For example, if I have a polygon thats 200x200m, perhaps I could plot a point at every meter squared ...
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1answer
33 views
QGIS raster area by clipped mask and 2 layers
I have two layers, one is a tif file with inclination of the soil of a whole county (which I got from the SRTM-relief) and the other file is a shape file which contains all the properties in this same ...
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39 views
Analyzing Overlap of Road Density and Polygons Using ArcGIS Pro
How do I calculate the overlap of a road density raster layer with polygons for each raster cell?
I want to calculate the area of a set of polygons overlapping each raster cell and the corresponding ...
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1answer
91 views
Calculate area with a buffer
I am looking for help for my master thesis.
I have two layers, a set of households and burned area (vector data). I created buffer zones around each household and now want to estimate the burned area ...
2
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1answer
112 views
Using area() or $area function in QGIS, when the data (polygon) is stored in UTM?
I have a question regarding the area() and $area function in QGIS and St_Area in PostGIS.
I am trying to calculate the exact area of Polygons stored in a Shapefile in UTM 25832 and do not know which ...
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1answer
69 views
How to display the current polygon area when editing in QGIS 3?
I use QGIS 3.10 to create new polygons manually.
I want to see the area of an object interactively during its creation.
I know that after creating a polygon, you can automatically calculate its ...
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1answer
58 views
Unexpected results for area calculation on two datasets in Google Earth Engine
I'm seeing a very strange result using .pixelArea() on two different layers that should yield identical results.
Code within GEE is here, also reproduced below:
var states = ee.FeatureCollection("ft:...
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1answer
163 views
Error in area calculation
When I run the field calculator to update area, the resulting areas are too large. This happens whether I use QGIS 2.18 or QGIS 3.4.
The default CRS is set to: ESPG:27700, OSGB 1936 / British ...
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1answer
236 views
ArcGIS projected area greater than geodesic area
Question
Shouldn't the geodesic area always be greater than the planar area of a polygon?
Background
Tested in ArcMap and ArcGIS Pro, but several my polygons in a shapefile are having projected ...
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1answer
394 views
Calculating area with ArcGIS ModelBuilder
This seems deceptively complicated. I have a clip of a large multi-polygon featureclass, and several of the polygons transect the clip barrier. How do I calculate the area of the new bisected polygons ...
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2answers
38 views
How you get the square containing a multipolyline
I use ST_Union to group a few lines. But realize some lines aren't supposed to be joined together after all. I would like to calculate the extent of the multipolyline so if the area is too big ...
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0answers
114 views
Completing network edges through an area using osmnx
Context
I want to plot a network (i.e. a graph, topologically connected where routing algorithms can be used) from openstreetmap data (this is linked with the python code snippet presented here: ...
