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Questions tagged [shape-area]

SHAPE_Area is a system field in a geodatabase polygon feature class that holds the geometric property 'area' for a shape. For the general concept of area, use the area tag.

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Absurdly large area estimates when extracting landcover area for individual polygons (CORINE Data)

I want to extract area under different CORINE classes as a part of my master's thesis. I am facing problems with the area estimates that QGIS calculates for landcover classes from the CORINE dataset ...
Tanvi Gurjar's user avatar
1 vote
1 answer
48 views

Calculate percentages of intersected layers

I have two shape layers in QGIS. Layer A shows the geometry of districts in Berlin. Layer B shows water protection areas in Berlin. The different areas/ geometries of layer B can cross multiple ...
kibi25's user avatar
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30 views

Convert Raster to Vector for forest area claculation

I have done my image classification for forested and non-forested areas. Now, I want to convert from raster to vector (polygon) in order to vew the attribute table and calculate the total area of ...
McJessey Leon Brian Beu's user avatar
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0 answers
141 views

How to calculate the polyline area in QGIS

How to calculate the polyline area in QGIS?I have the width and length and I want to calculate the area of the river using that information so I can redraw my river using the area size calculated. ...
Nurul Nabilah Mahmud's user avatar
4 votes
1 answer
634 views

How to calculate area in mountainous regions

My query is related to area calculation in mountainous areas. There is a simple method in QGIS to find the area of any polygon, like we need to project shapefile in the required projection system and ...
Shumaill's user avatar
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0 answers
591 views

Adding new auto-updating fields like [Shape_Area] using ArcGIS Pro

Currently in ArcGIS Pro, any polygon feature class in a gdb will have the fields [Shape_Area] and [Shape_Length] and these will be updated to reflect any changes to the feature geometry. This is very ...
user32907's user avatar
1 vote
1 answer
222 views

Creating a stack of annual images

I am working with the tropical moist forest dataset (https://forobs.jrc.ec.europa.eu/TMF/data.php#downloads) and I have a script where I can calculate the areas for a specific year based on landcover ...
TGUY's user avatar
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2 votes
0 answers
104 views

Finding and removing overlaps in a shapefile using PostgreSQL

I was wondering if it's possible to remove any overlapping areas that occurs in a column based on a sample of the table for the shapefile with 2 important columns: Shape area Geom I'm trying to find ...
Coffeee's user avatar
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5 votes
1 answer
424 views

Draw buffer around points considering slope in QGIS

I generated random points on a map. Around each point I would like to draw a circular buffer which considers the slope in that area, and within these circular buffers I would monitor tree height in ...
N_LLC's user avatar
  • 615
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1 answer
75 views

ArcMap calculate area automatically after edit

Is there any way to calculate area automatically when I edit a polygon? I mean, is there any function there I can use on area field and update itself when I finish editing?
Ali Dağ's user avatar
2 votes
1 answer
591 views

How to determine a polygon's area in a metric unit?

I have created a square grid and I would like to figure out the real world area of each polygon in a metric unit e.q. square metres via GeoDataFrame.area. import geopandas as gpd from shapely.geometry ...
Stücke's user avatar
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2 answers
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Calculate area for each raster value within a polygons (python) [duplicate]

I have a raster file and polygon shapefile. I need to calculate area for each raster value within a polygons. Example: the polygon below Total area = 1000 ha. I need an area for each raster value in ...
g123456k's user avatar
  • 600
3 votes
1 answer
1k views

Calculate 3D area with an DEM in QGIS

I have a lot of my projects that are located in mountains. When I draw my polygones, I can easily calculate $area, of course. But in many cases, I underestimate the surface of my polygons due to the ...
katagena's user avatar
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0 answers
143 views

CAD file hatching in QGIS

I have a CAD file work highway land acquisition plan. I want to hatch / solid fill in QGIS software, for to get area. See attached image This above file in CAD. What I want see attached image
Mohd Ishrar's user avatar
2 votes
1 answer
3k views

How can I fix a "negative shape area" on a simple polygon?

I have a simple polygon shape (single part, no holes, etc.) that has been imported (into a personal geodatabase) from third-party data (originally DWG and XML) that somehow has a SHAPE_AREA with a ...
Midavalo's user avatar
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0 answers
60 views

Why has the total area of polygon been reduced after using the splitting tool in QGIS 3.16.6?

I am using the splitting tool to split an original polygon (survey boundary) into smaller polygons (vegetation types). When I sum the total area of the shapefile after splitting (all the veg types) it ...
Nick Tidmarsh's user avatar
1 vote
0 answers
33 views

Distinguish between filled polygon and boundary

I am trying to convert the raster images to vector and get the inner filled polygon. But the filled polygon and its boundary are wrongly detected for some cases. Below is the code where I tried to ...
Souvik Sankar Mitra's user avatar
1 vote
0 answers
62 views

Creating complementary graph from GIS data (e.g., shapefiles) [closed]

I am new to GIS. I have some data about shapes, e.g., voting-districts, in several formats such as WMS, JSON, SHP. I want to create a graph (e.g., graphML) such that each district corresponds to a ...
Mike.K's user avatar
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1 vote
0 answers
49 views

Divide polygons based on internal differences in shape using PyQGIS

For my research, I'm trying to assess where we could potentially plant small, medium and large trees (with respectively 5m², 20m² and 45m² soil area needed). Besides patch size, also patch shape is an ...
Thomas's user avatar
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1 vote
0 answers
105 views

Different raster shapes even though I used the same clipping polygon (Python)

I have a bathymetry raster image that I would like to use for masking regions where elevation > -1. I have started by clipping the bathymetry image and another target image using the same ...
farhat's user avatar
  • 151
2 votes
1 answer
40 views

Why do Landsat images sometimes form triangles instead of 4 sided polygons to cover areas?

I put several Landsat8 images into ArcMap 10.7. I don't get the same kind of coverage (square area) you see in the first picture from the Earth Explorer site. I instead get picture 2: corners, ...
David's user avatar
  • 21
-1 votes
2 answers
1k views

Measure Points to Coastal lines?

I would like to measure the shortest distance from multiple points to a any part in a coast line of three different costs. How do I do this with QGIS or with SAGA GIS?
desputin's user avatar
  • 141
1 vote
0 answers
176 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 ...
Worg's user avatar
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1 vote
0 answers
109 views

Extracting raster pixel data in QGIS for project analysing deforestation rates

very new to QGIS and GIS software in general. I'm using QGIS to obtain spatial data from raster data for a spatial econometrics project I'm working on. I have 14 .tif images displaying change in ...
Thompo2106's user avatar
2 votes
0 answers
82 views

Raster:area() in R before and after projecting data

I have the following snippet of code: tracts<-readOGR('data/.') proj4string(tracts) "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +...
show_stopper's user avatar
1 vote
1 answer
2k views

Merging polygons without losing area using ArcGIS Pro?

I have a shapefile with 23 polygons,I want to merge them and get the total area of this big polygon. But when I used "merge"tool, it only merge polygons but area. Any ideas about what I should do?
WeiYuan Fu's user avatar
1 vote
0 answers
50 views

Difference in ONS area and area calculation in GIS-software

I have an official shapefile from the ONS (Office for National Statistics) in the BNG (British National Grid) projection. It has an st_areaha attribute column - I understand this is the area in ...
Newb's user avatar
  • 23
0 votes
0 answers
1k views

Lost/disappeared shape_length an shape_area fields

I have a vast database which includes a shape length and shape area field. One day, after doing some fc to fc layers from said feature class, I opened the attribute table and the shape length and ...
Alison's user avatar
  • 1
3 votes
1 answer
445 views

Polygon area calculation discrepancies using PyQGIS

I use the following code to calculate the areas of a multi-polygon shapefile. However, to validate these results, I calculate the polygon’ areas directly in table attribute by creating a new field and ...
ennine's user avatar
  • 863
1 vote
1 answer
215 views

Counting points creating polygon with ArcMap?

I am using ArcGIS Desktop 10.5. In land consolidation projects, to determine success of the project, we use shape indices. For this purpose to calculate shape indices, I need to know how many points ...
Fırat Arslan's user avatar
0 votes
1 answer
1k views

Calculating the proportion of area drawn over boundary file

I'm working with agriculture area data in MapInfo. I downloaded the boundary file from StatCan (call it STC), and a freehand draw tool downloaded here https://tinyurl.com/ydarsnq8 (call it DRW) I can ...
coolintake's user avatar
0 votes
0 answers
73 views

Equal area projection

In which projection I should project a polygon of a country to get the right area in the attribute table without a distortion? For example greenland
Tobias_Terra's user avatar
1 vote
0 answers
248 views

Sum area of multiple polygons of same layer that are all contained within different polygon

I have multiple polygons of the same layer that are all contained within another polygon of a different layer (please see the example below- picture is of Great Barrier Island and surrounding islands, ...
Zach's user avatar
  • 61
2 votes
1 answer
1k views

Which projected coordinate system for whole China?

I want to project data of China. I'm not concerned with trying to preserve areal or directional relationships but preserving distances would be nice. Does such a coordinate system exist?
Funkwecker's user avatar
0 votes
4 answers
4k views

Merge overlapping polygons (same shapefile) in ArcGIS without losing polygon area?

How can I merge overlapping polygons (same shapefile) in ArcGIS 10.3 without losing polygon area, i.e. the total area of the new, merged polygon should equal the area of all individual polygons ...
M_S's user avatar
  • 353
9 votes
1 answer
3k views

Area calculation in QGIS done two different ways?

It seems that there are at least two different ways to calculate the area of a polygon in QGIS using Python: 1) area = feature.geometry().area() 2) d = QgsDistanceArea() area_v2 = d.measurePolygon(...
banbar's user avatar
  • 1,009
0 votes
1 answer
2k views

Intersect automatically updating Shape_Area and Shape_Length in ArcGIS Desktop?

I am making a model in ModelBuilder in ArcGIS Desktop 10.1. I am using Intersect tool. I need to calculate the Shape_Area and Shape_Length of my polygons (Projected Coordinate System, EPSG: 5514, S-...
maycca's user avatar
  • 3,376
6 votes
1 answer
599 views

Calculating predominant value according to area within polygons using QGIS?

I am using QGIS 2.18.1 Las Palmas, in Windows 10, and that's the issue I want to clarify: I've got 2 polygon shapes. 1- One with river basins, and 2- other one with different levels of ...
Alex Fernández Poulussen's user avatar
3 votes
1 answer
7k views

Calculate polygon area in QGIS 2.18

I'm trying to calculate a polygon area. This is the polygon and the attribute table: When I open field calculator and use the Geometry--> area$, the area result for ID 1 is (in square meters) ...
newGIS's user avatar
  • 4,072
0 votes
2 answers
188 views

Ranking values by shape area using ArcPy

I'm trying to make a script that performs the following: it creates a new field that will hold values based on size of the shape area (from 1 to end of table), basically ranking them. I have a few ...
Geosphere's user avatar
  • 763
1 vote
1 answer
459 views

Calculate area intersected areas, problem [closed]

(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 ...
Jan-Willem De Jong's user avatar
0 votes
1 answer
280 views

Changed Projected Coordinate System back to original but, Shape_Area field is still off by about 55 SF

I recieved some GIS parcel data a little over a year ago. This data is the basis for the majority of my work. About a week ago I noticed that the Projected Coordinate System had somehow been converted ...
Rob's user avatar
  • 409
3 votes
1 answer
433 views

Row.Value returns rounded SHAPE.area and SHAPE.len values?

I have created a VB.Net Add-In, and am using IRow to get the value of fields in tables in ArcMap to use in a query. But I am encountering a problem when getting the values of the SHAPE.area and ...
Dan Jurgella's user avatar
  • 2,378
1 vote
2 answers
2k views

Shape area is not updated when importing shapefile from QGIS to Esri Geodatabase

I made some holes (difference) in a shapefile with Q-GIS 2.2.0, than I imported the shapefile in ArcGIS 10.0 and I exported the shapefile to a feature class in a File Geodatabase. In the feature ...
Carlo Pozza's user avatar
9 votes
1 answer
2k views

Determining Shape Area Field Name

I'm dealing with a varierty of spatial polygon files (shapefiles, file/personal gdb feature classes, sde feature classes (some with spatial views)) and depending on the file type, I get a mulittude of ...
Mike's user avatar
  • 2,281