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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1answer
134 views

Thiessen Polygon Total Area Calculations Model Builder/Python Code

I am attempting to create a tool using Model Builder (and Python code) for calculating the average annual precipitation of a study area using the Thiessen Polygon Method. My model runs good other than ...
2
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1answer
40 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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1answer
49 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, ...
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1answer
55 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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1answer
35 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 ...
3
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0answers
44 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 ...
3
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0answers
235 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 ...
3
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0answers
143 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 ...
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0answers
93 views

Why do each of my buffer-polygons have different areas

I`m using Qgis 2.2 and 2.4 and loaded a wms-map using the coordinate system ERTS89 UTM 32N. I set 8 points (all in on shp-fileand in UTM 32N) on various locations on the map. After that i created a ...
3
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0answers
139 views

What is the area that OGR extracts from the (geometry) shp files for polygons?

The ESRI July 1998 technical documentation for polygon shapefiles at page 10 makes no mention of either area measures or length measures (apart from byte/record-layout matters). Yet OGR enables me to ...
3
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595 views

Extract values from raster based on weighted average area using polygon grid

EDIT: I am using Armap 10 sp 5 I have found similar questions but they were either unanswered or somewhat different to what I am asking. I have a raster with cell values 1-5 and a polygon shape file ...
3
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0answers
120 views

Reshaping polygons while preserving area

I'm looking to manually skew the shapes of areal polygons, but need to ensure their areas are not altered. Is anyone aware of any GIS tools or programming workflows that exist for manually reshaping ...
3
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0answers
351 views

Getting coordinates of pixels

I want to compute an area of certain object on a picture using Monte Carlo method. The picture shows some shape on white background. To do so I figured out that I'd get the coordinates of non-white ...
3
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0answers
139 views

GeoTools, add column in query with CQL

I'm trying to query the database (DataStore) and want to let the datastore calculate a value for me. In SQL I would do it like this: SELECT name, ST_Area(ST_Intersection(the_geom, ....) AS myValue ...
2
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0answers
67 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, ...
2
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0answers
37 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 ...
2
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0answers
28 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 ...
2
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0answers
70 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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0answers
58 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 ...
2
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0answers
31 views

Why outside border of a service area is always not reasonable?

In ARCGIS 10.1 network analysis, why results of service area are different if number of break points is changed? For example, the grid is 300m*300m, I try to produce service area around a node. ...
2
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0answers
906 views

Projecting a Raster from WGS84 to planar Equal Area to Calculate Area: How to Select the Cell Size?

I have a broad question on how to calculate the 'correct' cell size for a raster when analyzing an area not at the equator. My goal is to project a land cover raster provided in GCS WGS84 to an equal ...
2
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0answers
127 views

Raster area (QGIS) problem explained

I would like to know the area that each value in a raster has... The raster I have has values from 2-15 and I would like to know the area that each value is occupaying within my polygon... Thanks! I ...
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914 views

How to calculate the area of a polygon considering the relief?

I work in a fire department and i'm mapping all the fires that occur in my area, creating polygons that represent burnt areas. my problem is that the values are not accurate... for instance, arcgis ...
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33 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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30 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 ...
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0answers
41 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 ...
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39 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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0answers
37 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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59 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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34 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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0answers
48 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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22 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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0answers
156 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
105 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 ...
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0answers
184 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 ...
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0answers
105 views

How to calculate the area of overlapping buffers within a single layer

I am very new to GIS, so don't know if this is EXTREMELY easy or impossible. I have GPS coordinates for stores (about 15000) for which I have created a buffer zone around each store location ...
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0answers
120 views

Problem with service area gap with Network Analyst

I am working on running Network Analyst to create a Service Area from a single location to all around it. Esri's network dataset was missing a couple crucial street lines, and so I uploading their ...
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0answers
81 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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0answers
35 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. ...
0
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0answers
26 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 ...
0
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0answers
81 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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0answers
36 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 ...
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0answers
255 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 ...
0
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0answers
116 views

Dividing a polygon into certain areas (open source solution preferred)

I have a polygon with an area of 50.000m². Now i want to devide this area in two polygons of different areas with a line layer. The left polygon should have an area of 30.000m² and the right polygon ...
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0answers
27 views

Show the paths but not roadsides and driveways in the line layer

I want to display paths in the woods but the paths are all in One (line) layer that contains all roadsides, pavements, drivvays, but also paths, tractor road and other relevant roads in, and up to the ...
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0answers
194 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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0answers
224 views

How do I optimize the speed and enable ArcGIS to create the Service Area around my locations?

The Problem: Every time I try to solve the service area around locations, ArcGIS crashes. It takes forever to load facilities and draw just a single polygon. How do I optimize the speed and enable ...
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0answers
82 views

Query area without “AREA” field

In ArcGis 10.2 I'd like to show only polygons over 1m2, using something like a query. Can I do this without adding an AREA field and calculating/populating it in my table ?
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2k views

How to split polygons based on other polygons?

In ArcGIS, I have a layer of polygons (created from the Service Area function) and want to split each one of those based on another polygon layer (the boroughs of London). The purpose is that I want ...
0
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0answers
397 views

How can I calculate raster cell area for upslope contributing area

I am new to spatial analysis, and trying to follow this tutorial to generate a topographic wetness index for my area of interest: ...