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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32 views

Area and distance calculation : scale problem

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 ...
4
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1answer
268 views

Tabulate Area ArcGIS

I am trying to work out the relationship between the 'processing cell size' and the result from Tabulate Areas. If one uses the same as the raster cell size, and this is the same for both rasters, the ...
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4answers
75 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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2answers
129 views

Converting area of a polygon from steradians to square kilometers using D3.js?

How can I find the area of a polygon in square km using D3.js? I'm not even really sure whether to use d3.geo.path.area or d3.geo.area. Here is my code (JSFiddle): var d = { "type":"Feature", ...
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0answers
137 views

Changing unit of area from unknown unit to square meters

I am using QGIS 1.8 and I have this polygon. I want to know the area of this polygon and I have used field calculator and it shows my area as 651692439. Under the general tab, CRS is EPSG:4326 - WGS ...
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1answer
26 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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1answer
48 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 ...
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1answer
31 views

How to aggregate values of different statistical areas that are overlapping?

Let's say I have one polygon layer counties with the polygons of administrative borders and another layer postal codes with the polygons of postal code areas. I have some statistical values per ...
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0answers
31 views

Append table returns null values in ModelBuilder?

I'm using Tabulate Area to count numbers of pixels in each class within buffers surrounding different points. I'm using model builder to perform this operation on many different points at many ...
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1answer
42 views

QGIS problem calculating area

I have a problem with qgis 2.8.1 (Wien). Whenever I change the project SRC to WGS84-World Mercator (EPSG 3395), the area is calculated as zero. How can I solve this problem? Is this a known bug? The ...
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1answer
78 views

Algorithm to detect entity (aircraft, ship, etc) intrusion into geographic area

I have been tasked with coming up with an algorithm to determine whether or not an entity (aircraft, ship, etc) is inside or outside of a geographic area defined as a set of geodetic (lat/long) ...
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1answer
631 views

How calculate areas between certain contour lines in qgis?

Sorry for asking a question which I found in similar ways already here, but I am trying this for days and just got no result: How do I calculate the area between certain contour lines (e.g. 0-800, ...
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1answer
36 views

Use of Google Earth Pro derived area and perimeter for a thesis?

I have ground-truthing data of centroids for 23 sites and their surrounding land uses, but no money to purchase remotely sensed images of this remote region of Latina America. I would use the polygon ...
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1answer
50 views

Calculate area intersected areas, problem

(I'm working in QuantamGIS) I intersected two layers creating a new layer. Within the attibute table of this new intersect layer i would like to calculate the new areas. However, it just doesn't ...
6
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2answers
173 views

QGIS area calculation differs when on the fly CRS transformation enabled

When I open QGIS, add the layer, and calculate the areas of the shapefile via field calculator I get a different area than when I open QGIS and check "Enable on the fly CRS transformation" and ...
2
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2answers
1k views

How to calculate volume from a raster file?

I have a raster file containing the depth of water. I need to find the volume of water using that raster file. I need to find the area of each cell and multiply with the depth. How can I do it in ...
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5answers
5k views

How to remove only donut holes from polygons using ArcGIS Desktop?

I am using ArcGIS Desktop 10.0. I have a trick for removing the donut holes, which is converting the polygon to line and then creating polygon out of the lines and in the end merging all of them. ...
2
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2answers
65 views

Find the area of points in PostGIS?

I have points that form a line. I would like to assign a radius to each point to give them volume, e.g. 50m and then find the area of the combined points. Does anyone know of a way to do this in ...
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2answers
186 views

Wrong $area from field calculator (QGIS)

The area of the polygons in a layer, calculated by the field calculator with "$area" is wrong (much too big) for some polygons. If I draw the concerned polygon again, the area is calculated correctly. ...
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1answer
52 views

Calculate area of a raster for an irregular polygon in PostGIS

I have a number of polygons with irregular shapes (i.e. non-rectangular) and want to calculate their areas after I have converted them to rasters. Here are my steps: Convert my geometry to a ...
3
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2answers
4k views

What are the units of the calculated area from a raster in decimal degree

I'm trying to calculate area for a raster file which contains 2 layers (0 for unsuitable habitat and 1 for suitable). It's been calculated successfully but I don't know what is the unit of the ...
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1answer
405 views

ArcGID Android SDK Calculate area in square meters from polygon geometry?

I have a Polygon object in ArcGIS Android SDK that I'm creating on a map, I would like to calculate that polygon object to square meters. currently I use double area=polygon.calculateArea2D(); ...
3
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1answer
89 views

QGIS 2.6 summarizing area (m²) for current atributes

If I have a code for each polygon and I have counted the area in m² for each of them (all this information is in single columns). How can I summarize these areas by codes (for example summarize all ...
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1answer
33 views

UPDATE a value field for area of the geom and convert sq m to acres using cartodb

I'm trying to use the SQL commands in CartoDB to UPDATE a value field that shows total acres of the area of the_geom. My SQL is pretty poor/entry level and has some issues: UPDATE table_name SET ...
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0answers
36 views

Systematic inaccuracy in QGIS shape area

I’m trying to find out why I get different area figure in QGIS than in AutoCAD when I’m using the same shape file? What I did is I drew a shape in AutoCAD, imported it in QGIS and used the field ...
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0answers
19 views

Changing Area Output - PUMAS

I currently have shapefile of US PUMAS and another feature shape file (call it feature X). I am using arcpy to project both of these files to the following projection coordinate system (using ...
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2answers
70 views

Calculate area size within a buffer

I have a park polygons layer and a set of points which I gave a 1000m buffer. For each of them I had calculated the area size with calculate geometry. So with which tool could I calculate the size of ...
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0answers
28 views

Can I display customer addresses based on their address?

I have a CSV file with a lot of addresses of customers. Can I import this and it display a point on the address and all other information from the CSV for this entry? I want to display later in wich ...
2
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1answer
142 views

Calculate area weighted average of attribute in one layer by shape in another

For a project I am working on I would like to intersect fire station response districts with income data to determine the median income per response district. However the borders of the layers ...
2
votes
1answer
51 views

Create a grid with statistics of the merged shapefiles in QGIS

I operate with QGIS. I have to split the shape files of the buildings and the roads of a city into a grid of 500x500m per square and into each square I have to obtain the total free area, the total ...
0
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1answer
38 views

How to use Calculate Geometry tool to calculate area

I have added a field in my attribute table but I cannot calculate the area. The units field is greyed out and the options at the top say "area - disabled". What can I do about this?
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0answers
94 views

Why does field calculator compute area in square meters?

I am using EPSG:102748, and have set my Settings/Option preferred measurement units to ft. My CRS is NAD_1983_StatePlane_Washington_North_FIPS_4601_Feet, and when I use the measure tool, it returns ...
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3answers
150 views

Summarize the total area of land use polygons within map sheets - how?

I would imagine that at least some of you have encountered similar problems to mine and I´d like to hear how you solved them. I have a map sheet index (a grid as a shape file) covering a large area. ...
4
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1answer
87 views

Equal area projections with different area results in ArcGIS for Desktop?

Using ArcGIS, I have to calculate areas of huge polygons all over the Pacific Oceans betwwen 20N and 30S. I have been trying different Equal-areas projections (Cylindrical and sinusoidal for example) ...
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0answers
73 views

Is it possible to calculate area of polygons from GPS points without POSTGIS

I am new with GIS. Assume we use the UTM30N coordinate system. Is it possible to calculate an area (say a square box) by the 4 given points? (assume the points are in order, and the coordinates are ...
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2answers
98 views

Tabulate Area in ArcGIS for Desktop not creating correct output?

I have used the Tabulate Area zonal spatial analyst tool in ArcGIS many times, and am encountering a problem for the first time. I am using a polygon grid (fishnet) as my zone dataset, and tabulating ...
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0answers
59 views

Using Tabulate Area 2 update for ArcGIS

I am trying to use 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 overlapping polygons in which ...
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0answers
35 views

How can i perform area calculations in a raster file?

I would like to know if is possible and how can i calculate all areas or parts of it in one raster? Can i do it using the raster calculator? All help is appreciated, Best regards
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0answers
67 views

Calculating vector area in QGIS

I have calculated a viewshed (ZVI) in OpenWind and opened the raster in QGIS I have then converted the raster to a vector When I open the attribute table there are 4682 rows (features) and there is ...
3
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0answers
94 views

How to calculate areas in raster files

I got three files. The first is a shape file for country boundaries and the second and third are two raster files with the global land covers for 2005 and 2009. I'm thus encharged to calculate the ...
2
votes
2answers
314 views

How to compute area for polygons in an EPSG:4326 shapefile?

I have a shapefile covering the whole globe, in EPSG:4326 (geodetic WGS84). I would need to compute the polygons areas in a metric such as km2. How can I do that in QGIS or with gdal/ogr and having a ...
1
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0answers
68 views

Determining homogenous blocks of individual tree species in a woodland, and creating a new shapefile without blocks/polygons of < minimum area?

I'm working on a project attempting to identify suitable woodland habitat for red squirrel translocation wherein conservation efforts could be focused. Below is a small section of the map showing ...
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3answers
108 views

Can I find out the exact areas which each category covers?

I have accessed a land use map and clipped the appropriate area I need to analyse. Is there a way I can find the exact areas which each category covers?
0
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1answer
25 views

Measuring roundness using buffers around centroids [duplicate]

I'm trying to measure the compactness (roundness) of some 800 polygons of different shape and size. I created the centroids and what I want to do now is to buffer those centroids with the exact same ...
2
votes
1answer
93 views

Area in KM from Polygon of coordinates

I have polygons from coordinates in (python shapely) that looks like this POLYGON ((24.8085317 46.8512821, 24.7986952 46.8574619, 24.8088238 46.8664741, 24.8155239 46.8576335, 24.8085317 46.8512821)) ...
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0answers
63 views

Unit of Geotools' getArea function

I have Polygons with WGS84/EPSG:4326 coordinates (like 13.57933804767844,52.5126298984133) and use the Polygon.getArea function to obtain the area of the polygon. But the result I get is something ...
4
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1answer
105 views

Comparing floor and roof areas using QGIS?

I am pretty new in this GIS topic and I would really appreciate if someone can help me with this problem. I am doing a research for university that shall show the available roof area for ...
8
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2answers
252 views

More accurate way to calculate area of rasters

In my daily work, I am constantly asked to calculate areas of global raster datasets in geographic projection at 30 arc second resolution. These datasets are normally the result of a Combine operation ...
3
votes
3answers
106 views

Calculate the majority of one polygon in another (fishnet)

I am looking for a method to calculate the majority of one polygon file (a map of ecoregions) in a sampling grid (fishnet) in ArcGIS. The purpose is to assign each sampling grid (fishnet) to an ...
4
votes
1answer
344 views

Cannot compute area of shapefile in field calculator of QGIS?

This shapefile represents the counties of NM. I am trying to compute the area of each polygon (yes, I know there is an area field, but this is a simpler example of a problem I'm having which doesn't ...