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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44 views

How to calculate areas for data that covers the whole of Australia [duplicate]

I have a polygon shapefile showing mining areas across all of Australia. I want to calculate the area for each of the polygons however they have been provided in a Geographic Coordinate System (GDA_94)...
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73 views

What data projection should I use for area analyses in different countries at a global scale

I'm creating A4 maps to show where forest cover and mining fields overlap across the globe. Each A4 map focuses on a specific country (e.g. India, USA, China, Australia...). For each country, I need ...
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42 views

I have a land cover vector dataset, and would like to calculate the area of each land cover in ARC, how can this be achieved?

My land cover vector 25m data includes land cover types such as 'Broadleaved woodland' and 'urban'. I have cropped the dataset down to my study area and would like to calculate the area of each land ...
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70 views

Show groups of coordinates on a map, to visually find coordinates that belong to the wrong group

I have a (very) long list of casinos. Each casino has: latitude longitude boss (a single boss runs from 1 to 50 casinos) Sample: 40.642 -73.997 Freddy Queens 40.680 -73.985 Freddy Queens 40.697 -...
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130 views

Area calculation of mapped categories in ArcGIS 10.1 Basic

I have performed supervised classification (Interactive supervised classification and Maximum Likelihood Classification) on landsat reflectance raster data to classify it into seven land use ...
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1answer
101 views

How does ST_Area in PostGIS work?

I am performing a simple calculation on a polygon known to be approximately 6226 km^2 in area. It is stored in a Geography (WGS84 SRID) column. The query is: select st_astext(col), st_area(col) area ...
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68 views

Creating polygon features on scanned historical maps to measure areas in ArcMap?

I have a collection of historical scanned topographic maps from the 19th century that have already been georeferenced (NAD 1927). I'm uploading the maps as JPGs into ArcMap and would like to use the ...
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55 views

problem with area calculation in QGIS [closed]

I encountered a problem in QGIS 2.10.1 when I tried to calculate the areas of polygons in a polygon layer. I followed the instructions here (http://manual.linfiniti.com/en/vector_analysis/...
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47 views

What is most accurate Spatial reference system for calculate Area entire world [duplicate]

I want to know what Spatial reference system is most accurate to calculate area? I want to use it for entire world (-180,+180,-90,+90 area in WGS84 system) I have every thing ok I only need to ...
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43 views

$area calculation doesn't work or wrong projection?

I've been reading the QGIS manual and I've encounter a problem I don't know what to do. I downloaded data from OpenStreetMap and the raster from http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp The ...
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145 views

Area Calculation incorrect

In ArcGIS 10.2 I created two buffers using the default settings one with a distance of 1 kilometer. When I calculated the area it has a square kilometer area of 3.14. All seems fine there to me. ...
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49 views

Limit Cartodb map to single geographic area

This should be really simple, but I've screwed up a map several times trying to figure it out and I'm working on a deadline, so I don't have any more time to play around with it. I just want to ...
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0answers
87 views

Area Calculations dont agree after raster to polygon conversion

I have a landsat 8 image [UTM 19s] (30m resolution, so 900m sq per pixel). I need to calculate the total area (hectares) from a land cover type. I take the count of pixels from the attribute table, ...
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0answers
38 views

Calculating % of Vegetation type burned by 0/1/2/3…fires in ArcGIS?

I am trying to plot the proportion of each of the major vegetation formations burnt by 1,2,3,4,5,6,7 etc fires (that is a frequency histogram of % of total area of that vegetation formation (e.g. ...
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1answer
218 views

Find the area of a map (Xkm x Ykm) from the left & right longitude and latitude

How can the area of a map from OpenStreetMap be determined in the form of Xkm x Ykm, given the following information: Left Longitude = 103.554879 Right Longitude = 103.740497 Top Latitude ...
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2answers
409 views

Deleting polygons smaller than certain dimension using ArcGIS for Desktop?

I've made a model in modelbuilder in Arcmap 10.3, what it basically does is creating polygons over open areas such as farm-lands, grass-lands, marshes etc that has a low slope. My challenge is that I ...
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1answer
67 views

Getting different values for area field calculations using ArcGIS Desktop?

We have self developed application based on ArcGIS 9.3.1 SP2. Our agents use that application to edit parcels. The parcel layer has a field SHAPE_AREA that is calculated by ArcGIS. Our application ...
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128 views

Only displaying polygons over certain size in ArcMap using Definition Query?

I have a polygon containing lots of bodies of water and only want to display the bodies of water over a certain size. Can I do this using a definition query?
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40 views

Clip feature according to its areas

I have a layer that has several overlapping areas (coming from CAD). So usually I do a "SORT" (tool), so I can view all the features. However, I wonder clip a shape according to their areas, it's ...
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0answers
44 views

Calculating the the area of overlapping polygons

In ArcGIS, I have a shapefile for a pipeline and another for plots of land that the pipeline shapefile touches and I was wondering if there is an obvious way to calculate the area that the pipeline ...
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70 views

Tabulate Area 2 Tool not returning correct area

I am having trouble with the output of the "Tabulate Area 2" tool in the following update: http://blogs.esri.com/esri/arcgis/2013/11/26/new-spatial-analyst-supplemental-tools-v1-3/ I have a layer of ...
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89 views

Is there a way to draw polygons with a fixed area?

I am looking for a way to draw polygons with a fixed area. I am currently mapping farming options on field parcels. Some areas such as buffer strips run along features like rivers and hedgerows so ...
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1answer
428 views

How to calculate WGS84 (EPSG:4326) area in C# or SQLGeometry?

I am not normally a GIS developer, I am just helping out with a bug and I am stumped on what is going on here, could I get some help please. I have two calculations, one in 4326 (WGS84) and one in ...
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100 views

Calculate area above elevation threshold

I have a number of 95% isopleths (polygons) that represent animal home ranges. For each isopleth, I and want to calculate the Area (sq km) above 2000 meters. My initial thought was to create ...
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27 views

Common methods of area comparison?

I have a set of raster area results, that represent a prediction for a specific loccation. I would like to measure accuracy of two methods, given the actual values, estimate-A method values and ...
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1answer
59 views

how to get area in qgis 2.6.1 brighton?

I'm using QGIS 2.6.1 brighton, and I have a problem in computing the area of each layer. I was actually working on the map of our municipality and I would like to compute the total area of the ...
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74 views

How to calculate the area within a 4m clipped buffer derived from a raster

I am using QGIS 2.8.3. I started by classifying my area into habitat types using the semi-automatic classification plugin (SCP). Then I added points, and a 4m buffer around the points. So I could then ...
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1answer
47 views

How to use the hml <area> tag together with Openlayers 3 raster layers?

In order to include interaction to my Openlayer 3 raster layer, I would like to use something similar to the html <area> tag (http://www.w3schools.com/tags/tag_area.asp). The aim is to click on ...
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1answer
143 views

How to calculate overlap area of two polygons?

I am a beginner in the world of GIS. I have one table polygons with each polygon having north-east and south-west coordinates. And for every polygon, I need to find area of overlap with other ...
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1answer
181 views

How to calculate the form (or shape) factor of a polygon?

I am using QGIS to calculate the form (or shape) factor of polygons following what Louf and Barthelemy did here: http://rsif.royalsocietypublishing.org/content/11/101/20140924 The form factor is ...
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93 views

How to get geodetic area? rgeos::gArea doesn't seem to work. Or area-preserving projection

I need to get an area of different polygons at continental scale (like third of Africa etc.). Usual functions like rgeos::gArea work only in the projection units. Is there any function which works ...
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95 views

How to measure the sum of the areas of each class in QGIS?

The project has a layer with several groups of polygons with different weights. Each group is associated to a weight. How can I get the sum of the area of each group?
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1answer
149 views

Routing Service that Avoids Areas?

I'm just starting with GIS, and I'm looking for a routing service that will allow me to avoid given regions on a map, or to build my own router that has this functionality. The site OpenRouteService....
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1answer
195 views

Variable width buffers depending on surface area (Arcmap 10.1)

I know this is a pretty basic question but I couldn't find the answer myself, so here I go: I need variable buffer widths depending on the surface area of the polygon (city) size. For example: A ...
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1answer
76 views

QGIS updated polygon areas

I'm using QGIS 2.6 and regularly update a shapefile layer to indicate felling progress. However, if I edit the nodes of a polygon, save the layer out then look at the Attributes table the area shown ...
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40 views

Z factor to get the results in square meters and cubic meters?

I have a DEM surface in WGS 1984.I want to calculate surface area and volume in different elevations.I wonder for example If I want to measure the area and volume below some height how shall I set the ...
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62 views

calculate Z~F from polygon and raster

I have a polygon shapefile and raster layer. How I can calculate the elevation and area (Z~F) relationship for each polygon by using QGIS or ArcMap?
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37 views

Clip only works on some areas, and not on others, despite being from the same dataset

I have a shapefile of provinces (nxprovincias), and another shapefile of small, disconnected areas ("protected areas") that overlaps with the provinces. I want to easily calculate the total area of ...
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1answer
129 views

Calculating area using dissolve and merge but getting shapefiles with empty attribute tables in QGIS?

I have a shapefile of a country with the 29 provinces. I also have shapefiles with the areas which are protected from construction (there are 4 categories for protection, within 4 shapefiles. Some of ...
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2answers
511 views

Polygon area calculation in Ruby (on Rails, rgeo, PostGIS and GEOS) in sqare meters

In a Ruby-on-Rails application, I need the area in square meters (or any other surface measure, be it ares, hectares, square kilometers, but not in pseudo surface measure like square degrees) of a ...
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1answer
496 views

Calculating Area of Intersecting Polygons and Buffers

SO, in QGIS I have several points with 1km buffers around them; some of the buffers overlap. Within the buffers are a number of ponds, which I have a shapefile for. I want to calculate the area of ...
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26 views

Forcing area calculation into miles in QGIS (without changing the PCS) [duplicate]

I'm working on an assignment that requires me to create an area column in miles without changing the projected coordinate system. ArcGIS has a tool that can do this ('Calculate Geometry')-- does QGIS ...
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1answer
43 views

Measuring watershed area using pixel accumulation?

I am doing watershed delineation at the continental scale using a GTOPO30 DEM, projected spatial reference WGS_WGS_1984_UTM_Zone_15N. Using Arc10.... My basic workflow using ArcHydro tools: Project ...
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0answers
18 views

calculating total area of multiple polygons in qgis [duplicate]

I wish to know the total area of all polygons within a shapefile layer. So far I have added a new column to the attribute table that shows me the individual area of the polygons.I tried to copy the ...
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2answers
435 views

Get Area size using Dragbox in Openlayers 3

I need to be able to show the square meters of an area using dragbox. There's a great example using draw polygon, but I need to limit users to a regular rectangle. The formulas and SHOULD be the ...
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2answers
247 views

R apply function in turn to each subset of a spatialPolygonsDataFrame

I'm trying to get the area of all the polygons in a SpatialPolygonsDataFrame: parcProj. library("rgeos") gArea(parcProj[2,]) works fine but: apply(parcProj,1,gArea) or sapply(parcProj@...
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1answer
92 views

Area and distance calculation/measurement unexpected after projecting? [duplicate]

I have converted a GIS shapefile of Botswana from the geographic coordinate system GCS_WGS_1984 to the projected coordinate system Africa_Albers_Equal_Area_Conic to be able to calculate the area of ...
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1answer
90 views

Calculating area of residential area wihin multiple ring buffer in ArcMap?

I need to calculate the size of residential area within 0-250m, 250-500m and 500-750m of a bus stop. I have made a multiple ring buffer around the bus stops. And I have a shapefile of the residential ...
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4answers
165 views

Calculate minimum area where x% of raster value total is concentrated within polygons

I have a raster layer (chlorophyll concentration) and a layer of non-overlapping polygons (regions of the ocean). For each polygon, I'd like to calculate the area where the majority of chlorophyll is ...
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1answer
915 views

Area is calculating wrong using $area in field calculator (QGIS 2.8.1-Wien)

There is a similar question posted, but the solution to it seems to be that polygons were multipart: Wrong $area from field calculator (QGIS) In my case, all polygons are singlepart. I have several ...