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 polygon within square mile in ArcGIS?

I would like to create a raster, where in every cell it returns the area of land in a polygon feature. So for example, every cell in the raster would give park land per square mile, or vacant land ...
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2answers
49 views

Calculating relative share of area covered by water/percentage of polygon area that overlaps in ArcGIS for Desktop?

I need to calculate the share of the area within a 50km radius of major German city centers that is covered by water with either Arcmap 10.3.1 or Qgis 2.14. My plan is to use the Global Lakes and ...
3
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2answers
39 views

Tiny difference of calculated area of polygons

I have a shapefile of about 62.000 polygons. I calculate the area of each polygon on a field, named AREA1, with Calculate Geometry option. Secondly, I create a new field field named AREA2. I calculate ...
2
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1answer
34 views

Area calculations using a layer in a projected data frame versus a projected feature class in ArcGIS

So I've been tasked with automating a formerly manual process in model builder in which I'm trying to calculate land area. In the former manual process the feature class was brought into ArcMap and ...
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0answers
9 views

Allocating premises between postcode polygons and telephone exchange area polygons in QGIS?

I have telephone exchange areas as one polygon layer and postcode (codepoint) polygons as another. The postcode polygons have the number of premises in each postcode as a field. I want to estimate the ...
2
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0answers
53 views

Size of an object in raster image based on DPI resolution and number of pixels

I'm trying to estimate the size of an object in a raster image, with known DPI resolution. To evaluate the validity of this method, I do as follows: 1) I'm drawing a 0,02 in × 0,02 in black square ...
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0answers
14 views

Why do area calculations of OSM polygon shapefiles return negative values in ArcMap?

Whenever I tried to calculate the area of polygon shapefiles (OSM, Geofabrik) part of the polygons have negative values. All values appear to be right except the fact that around half of them are ...
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2answers
22 views

Over-calculation of area due to parcels occupying same space

I'm trying to get the total acreage of different parcels by land use, and unfortunately I keep getting a total of ~15000 acres instead of ~12000 because it's over-calculating the area where there are ...
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1answer
26 views

Select Adjacent Tax Parcels by Area

I am trying to select for adjacent tax parcels where their total area would be close to a specific value (450 acres). Area is already an attribute of each parcel. ArcGIS v. 10.3.1 Unfamiliar with ...
3
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2answers
92 views

How to calculate the relative share of an area of a circle that has a slope >15% in Germany

I need to calculate the share of buildable land for the 15 major german cities within a 50 kilometer radius of the city center. Part 1 of the definition buildable is that the area must have a slope ...
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0answers
19 views

Finding measuring units [duplicate]

Every time I perform the geoprocessing tools buffer or intersect, my layer gains two more attribute columns, named "Shape_Leng" and "Shape_Area". How can I know in which measuring units are these ...
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2answers
38 views

Group points and compute area

In a point vector layer, how to compute area for 4 defined ranges of values of one attribute? On the example below, I want the total area for each of the 4 colours.
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0answers
28 views

how to calculate area if it is falling in two utm zones [duplicate]

I am using ArcGIS 10.1. How do I calculate an accurate area measure for a polygon, where portions of it are falling in two zones, i.e. UTM ZONE 44 & 45 (India)?
2
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0answers
42 views

Calculating Area for data in WGS 84 using ArcGIS for Desktop? [duplicate]

I am using ArcGIS 10.1.1 for Desktop on my laptop. When I try to calculate the area in WGS 1984 the area is disabled. If I work in one projection, say WGS 1984, and calculate area in another ...
2
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1answer
53 views

Area biased in 1x1 km2 vector grid in QGIS

I used Vector -> Research tools -> Vector grid with enabling Output grid as polygons to create a 1000 by 1000 m grid from a shapefile. However, when I calculate the area of each grid cell ...
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0answers
45 views

How to scale polygon to obtain specific area in javascript?

I have got a source polygon (saved as standard js array). I want to scale it down to obtain new destination polygon in the centre with 1/3 of source area. On the cartesian space i just scaling down ...
3
votes
1answer
86 views

Calculate the polygon area

I am using QGIS 2.12.3 Lyon and I want to calculate the area of my polygon in m2. For that I used the tool provided by QGIS, but the result is not as it should be. I got from QGIS 50 ha, while I got ...
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0answers
50 views

Dividing a shape in equal pieces?

I have data in Autocad. As you can see there's a buffer (purple) inside of the blue shape, I want to divide the blue shape to small equal pieces that have the same surface area. What I'm looking for ...
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44 views

calculate area using pixel count (ArcMap)

I have been trying to research solutions and solve my problem for a while now, without success. I have a raster file with 2 layers, namely 0 and 1. My attribute table includes the pixel count for ...
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2answers
65 views

QGIS NDVI Spatial Analysis

I have an NDVI raster that I would like to reclassify into some arbitrary bins i.e. all values between 0 - 0.2, 0.2 - 0.4 etc. for spatial analysis. Could anyone advise how to: 1) reclassify a ...
3
votes
1answer
73 views

Calculate area of geometry derived from current feature in QGIS 2.8

I'm trying to create a new field defined as the area of the convex hull of the current feature, in the Field Calculator in QGIS 2.8. Calculating the area of the current feature is easy ($area), and ...
2
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1answer
110 views

How to calculate marker area on OpenLayers 3?

I have the following scenario: a polygon (or few) and a marker which is displaying some data of its related geometry/ies: What I want is to manage the map's zoom level in order to decrease the ...
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29 views

Trouble with Calculate Geometry in ArcMap 10.2? [duplicate]

I got a "Federal Lands" shapefile from nationalmap.gov. I clipped it down to the geography I am focusing on (a few counties in eastern California). I am trying to use the "calculate geometry" tool to ...
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0answers
37 views

Calculate obstacle accountability area in QGIS

Still being new to the whole GIS world, I am trying to calculate a regulatory takeoff obstacle accountability area for a given runway. For my case, this is defined as an area as follows. At the start ...
3
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2answers
60 views

How to calculate area in sq m - troubleshooting projection issues in a global dataset in QGIS

I am using QGIS version 2.12.3. I have 3 polygon shapefiles: A, B and the intersect of A and B, which we can call C. All I want is to add a field to the attributes table of each shapefile giving ...
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0answers
39 views

QGIS Modeler different results by calculate the $area

When I use the graphic modeler,add a field and calculate the area, the sum of the area of all records is different to result which I get by calculation in the fieldcalculator. The result in the ...
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1answer
43 views

How to determine area from polygon? [closed]

I have to digitize one polygon that can accommodate 10million.cubic metre of waste and the study area is completely flat surface. How to determine area?
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1answer
18 views

calculating ratio of areas on a sphere

I have 2 shapefiles and after identifying their intersections I'd like to know the ratio of intersecting areas, e.g. a given shape S in file1 intersects with shapes (x1,...,xn) in file2 with ...
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1answer
33 views

Area estimation using raster image

I have a map of trace gas (NO2) distribution over big cities and other anthropogenic objects. The purpose is to estimate the area of distribution. I attached the sample image to illustrate what I do. ...
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0answers
54 views

Wrong area using Albers Equal Area Projection in GRASS for Java, Indonesia

I am just getting to know GRASS 7.0 and I am struggling finding a good projection to work on a spatial analysis of Java, Indonesia. I am new to the forum, so if information's are missing for a better ...
8
votes
1answer
282 views

Circle area calculation in QGIS is inaccurate

I created a circle with a radius of 3 km, calculated the area using field calculator and got a different result from real area. The QGIS result is 28273078.8 while manually calculated area is ...
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0answers
82 views

Projecting GeoJSON polygon object in python to calculate area

I have a script, written in python, that does many calculations - but one set of calculations hinges on determining the area of a polygon that I read in, in GeoJSON format. I can convert this object ...
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1answer
71 views

Calculate total coverage of circles on map with PostGIS

I am trying to calculate the total area covered by c.a. 400 Circles of diameter 15Km. The centers of these circles are stored in a column of type geometry:4326 in my database. Some circles overlap, ...
0
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1answer
37 views

how to calculate polygon area using field calculator QGIS? [duplicate]

I am trying to calculate the areas of some polygons and i want to use the field calculator to measure the area. The result i got using this method is different from using the QGIS measurement tool. I ...
0
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2answers
134 views

How to determine objects area (size) measurement error using satellite images?

I am working at scientific paper about measuring object's size (it's area) using satellite images. I got some progress in it and need to compare my results with other scientific works. I have found ...
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0answers
31 views

Identifying Open Areas in OpenStreetMap?

I am currently creating a system using OpenStreetMap (OSM) and I need to identify open areas in the map. I know there are existing open areas on OSM but is there a way to identify more open areas ...
1
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1answer
111 views

Finding the area of polygons within other polygons in R

Is there a function in R which will loop through a layer of zonal polygons (i.e. a polygon grid) and return the area of a second polygon layer that is contained in each grid cell? I have a layer of ...
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0answers
11 views

How to calculate area percentage from polygons from one shapefile within another? [duplicate]

I'm working on a project where I have to create python code that takes land-use data and adds a percentage field for each land-use category in a Census Tract shapefile. I've been trying to work with ...
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0answers
23 views

What is the right projection for area calculation in Kenya? [duplicate]

I want to calculate the area of counties (1st admin level) in Kenya in ArcGIS. What is the right projection for that? I know I should use an equal area projection, but when I use them (I tried six ...
1
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1answer
49 views

Summarizing areas of features of multiple classes

I am conducting a buffer analysis on a vector feature class of Urban-Wildland Interface zones, and am trying to calculate the total areas of each particular classification of interface area. As I ...
0
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1answer
93 views

How can I draw a polygon with a fixed area in ArcMap

Is there a way to draw a polygon with a fixed area in ArcMap? For example, I'm trying to create a 40,000 foot boundary around a feature, but the boundary does not have to be any specific length or ...
1
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1answer
39 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 ...
1
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2answers
64 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 ...
0
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2answers
39 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 ...
1
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1answer
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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2answers
105 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
84 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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1answer
64 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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0answers
52 views

problem with area calculation in QGIS

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 ...
0
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1answer
44 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 ...