A density map depicts a number of objects per unit area.

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Union or Times for overlaying two maps?

I have created two different raster maps by Kernel density, one for street connectivity density and one for residential units density. I classified each of them in 5 classes with high density, high-...
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2answers
443 views

Density analysis producing extreme values?

I have point data of gas flares and I am trying to create a simple density raster of those flares. Results are either 0 or in the 100,000-1,000,000 range (when there's 5 to 40 or so points in each box)...
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43 views

How to build a raster (population density) dependend diagram in QGIS?

I'm using QGIS and trying to solve the following problem. I got 2 layers: 1. population density raster 2. point layer with the information about number of people could be hosted/served etc in this ...
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1answer
62 views

Displaying heatmap with large number of dense points of interest in QGIS?

I am currently trying to make heatmaps of bird observations in an area. I have had a lot of success making the actual heatmaps for most birds, except the ones that are extremely abundant. I use the ...
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1answer
47 views

Line density map in QGIS

I would like create something like that in QGIS: http://2.bp.blogspot.com/--EFSaghZ92s/VqQXXIoE4AI/AAAAAAAABKw/KGkoB8zZ6K8/s640/scs2%2Bmap.jpg I have a huge amount of points and I can import in QGIS (...
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1answer
44 views

Calculating population density from urban raster reclasiffy

I am using ArcMap Out of a raster, I reclassified it into only having the urban areas. I ran this through zonal statistics and got the area of the urban area (in meters, which I presume are in ...
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2answers
1k views

How to densify a polyline according to a specific length? [duplicate]

Possible Duplicate: Add vertices to lines I am using QGIS 1.8.0 I would like to densify a polyline according to a particular length of segment (ex. 200 m). I know it is possible with other GIS ...
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118 views

Interpolating species data from sample points in a small area [closed]

I have sample data from a small site (10 acres) which shows the number of occurrences of a particular species of snail over two sampling periods (fall and spring sampling). I want to try and ...
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18 views

Calculating intensity of a 0…1 scale

I'm trying to come up with the Intensity value for the Cells dataset (Diggle 1983). This dataset has coordinates from 0 to 1, probably percent, there is no actual unit to it as I think it was taken ...
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2answers
97 views

Variation on a density map QGIS

I am trying to figure out how to make a map that can represent the density estimates that I have. The estimates are tied to points, but are for 1 hectare (100m*100m) areas of which the point is the ...
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1answer
77 views

Showing density of overlapping features via transparency in ArcMap?

Below is a famous map produced by the Facebook team, which shows the connections between their users. Where there are multiple overlapping features, the lines show more brightly, giving a clear ...
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30 views

Percent coverage of a polygon in a raster grid

I have a wooded area polygon and a study area grid of cells with 300m resolution. I would like to calculate a raster which shows the amount of each grid cell covered by the polygon. The density per ...
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1answer
78 views

Estimating population in flood zones?

I have a census tract shapefile with the population of a minority group and total population. I am trying to analyze this group by high and low risk flood zones. The problem is that not all of the ...
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0answers
30 views

Is Hot Spot analysis appropriate if you see hot spots in areas that you would expect to see them in?

I am working with vessel position data on ArcGIS 10.0. My customer has requested density analysis maps. I was curious if hot spot analysis would be a more appropriate analysis? The study area is along ...
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3answers
2k views

How to interpret GRASS v.kernel results?

GRASS manual reads: v.kernel - Generates a raster density map from vector points data using a moving 2D isotropic Gaussian kernel ... Ok, but how do I interpret the results? I understand that v....
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5answers
3k views

How to identify “true arcs” in Arcmap?

This is really annoying: the only good way of creating circles in ArcMap is using true arc, (compound curves) but I need to convert those to vertex (densifying) because of a compatibility problem. I ...
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1answer
636 views

Interpolating values within certain distance of points using ArcGIS Spatial Analyst?

Let's say I have a set of points representing bridges. I want to create a kind of "heat" map that would highlight areas within my study area that has many bridges in good or bad condition. I have a ...
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1answer
195 views

Finding distance within which set percentage of features fall using ArcGIS Desktop?

Is there a tool that tells how many features there are within a set distance in ArcView? asked about finding the number of features within a certain distance of another feature in ArcView. I have ...
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1answer
48 views

Arguments error when running LineDensity scripts in arcpy

I'm trying to use LineDensity tool on polyline features. The shapefile is small and includes some invalid geometries. The code I use is an adaptation of an ArcGIS Help script. Here is my code: ...
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128 views

Counting number of plants in area using images from UAV?

How do I count the number of pineapple plants in a 1-hectare block? I have heard of these algorithms but I don't know how to do it. I'm still a newbie of QGIS, ArcGIS and ENVI. I have the NIR, RGB, ...
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36 views

Density of different sized Point-, Line-, and Polygon-Features with ArcGIS 10.3.1

I'd like to analyze the density of Point-, Line-, and Polygon-Features with the tools “Point Density” and “Line Density” with search_radius from 1000 Meter. But now there are also Polygon-Features ...
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2answers
279 views

Where to find Population Density (shp. or grid) for Europe? [closed]

Does anybody know where to download shp. or grid file on European population density (inhabitants/ sq.km)?
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51 views

How to measure the compactness of a set of points

I'm looking for ideas on how to measure the compactness of a set of points. The idea is similar to identifying clusters, but instead I want to compare two distinct sets of points and return a measure ...
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1answer
21 views

Scale and density values in density map appear wrong when in projected coordinate system?

I'm making a series of maps illustrating different aspects (road density, location of dams, elevation etc...) of a single watershed in California. In most of my maps, I've had the projection set to ...
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234 views

Get all locations of Panoramio photos in a given extent

To create a visual quality heat map I'm trying to get a list of all Panoramio photos in an about 2000 Km2 wide study area. My idea is to perform a density analysis in GIS on a point shapefile ...
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1answer
62 views

How to reduce points by proximity

I got a layer with over 4 million points. The distance between the points are 1 meter. How can i reduce the data so that no points have less than e.g. 10 meters between them?
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2answers
5k views

Creating density map from point data?

I have point data, where one point represents one 1 storm water outfall, looks like this: (point data is across all of Long Island, New York). I am having a bit of difficulty finding the best tool ...
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1answer
136 views

find the population density of some points in qgis/postgis

I have the tiger census data of population density in each block group. I also have a different kind of data: traffic accident data, where an accident has a lat/lon pair. My goal is to find the ...
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2answers
213 views

Summing up over area based on distance related function?

Through a field study, we learned that the density of a bird species in the forest was related to the distance to forest edge: ln(density) = 1.89*(distance to edge) + 0.34 Now, for any forest polygon,...
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1answer
229 views

ArcGIS dot density for small areas

I'd like to use dot density to display some data in Arc, but the areas (polygons) I'm displaying it for are so small in some cases that I suspect the pattern is being misrepresented. If several ...
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0answers
47 views

Help Summing Raster cells to equal circles with a specific sum

So I have this application user density data that I've collected. Each gps point has a user density associated with it (for example: 150 users within a 1 km radius, which calculates to users/[pi*R-sq] ...
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1answer
28 views

QGIS Grid Union Issues

I am trying to create a choropleth map of ice concentration over Lake Erie. I have data for all the lakes (I can clip it all at the end), which are in a point shape file. I have laid a grid over the ...
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92 views

Find hotspot with highest density for two objects

I'm using PostgreSQL/PostGIS and I have an advanced type of query. My database contains two types of objects - let's say homes and crime. Is there a way that I can find the area with the densest ...
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305 views

Find area with highest relative density of one type of object

I'm using PostgreSQL/PostGIS and I have an advanced type of query. My database contains two types of object - let's say pubs and churches :) Is there a way that I can find the area with the densest ...
3
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1answer
2k views

How to Calculate Utilization Distribution Overlap Index (UDOI) in ArcGIS Desktop?

I was wondering if any of you happen to have any information on how to calculate the Utilization Distribution Overlap Index (UDOI) in ArcGIS 10? If I understand it correctly the UDOI takes two kernel ...
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2answers
568 views

After turning census block data into a raster, how do I redistribute the density to reflect land cover types

I plan on rasterizing (terminology?) census block data relating to density to a regular 30 m by 30 m grid for use with NLCD data. I then hope to distribute the density of the original census block ...
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90 views

Low point density analysis

I'm working on a project for a conservation plan. Part of the plan requires that areas added for conservation have less than one structure per five acres (these are pretty large, mostly undeveloped ...
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1answer
476 views

How to make a density map from polygons/rasters (ArcGIS)

I would like to make a density map of grasslands. I have a vector layer of habitat classifications, I would like to a density map of grasslands within a specified radius. My thoughts are to: ...
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100 views

What are the units of a Weighted Point Density analysis?

I have point locations of trees and their associated diameters in cm. I performed a point density analysis in ArcGIS of these locations weighted with each points' diameter and the resulting units in ...
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211 views

Kernel vs Point density

Can someone give me an example each where these two tools would be appropriate to use. I kind of understood what each of them does but can't seem to figure out examples where one would be more ...
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2answers
5k views

How to create a heat map or density map from stacked polygons in ArcMap 10

I have a polygon shape file that has many overlapping features. Each feature represents an area used by polar bears. So some of the polygons overlap and some don't, and there are separate clusters of ...
5
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0answers
678 views

Spatial join to kernel density / kernel density with polygon/point output in Arc [duplicate]

I'm looking for a way to join polygons to a density function for some other feature of interest. Current workflow make density raster from feature set of interest, using point/line/kernel density ...
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2answers
1k views

road density km/km2 calculation

I am trying to calculate the road density in my study landscape. I am using the spatial analyst, and the line density function. By default, the tool is setting a cell size of 3.6km*3.6km, and the ...
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0answers
179 views

Search Radius for Line Density [closed]

I have been working with GIS for many years but I am fairly new to the spatial analyst side of things. I am working with many satellite tracks for many different individual animals and would like to ...
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1answer
255 views

How to do dot density in ArcGIS Online?

I have some census tract polygons with language spoken at home attribute data behind them. I created them in ArcMap and produced a dot density map. However, after importing to AGOL it's only the ...
5
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3answers
2k views

What is the highest resolution of population density data that I can obtain for USA freely?

Ok so as far as my understanding goes the most high resolution dataset available that factors in many other things (other than Census data ) at a 1X1 km resolution is Landscan data created by Oak ...
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1answer
36 views

Accessibility indication from points

I will simplify my question to be better understood. Let's suppose my study area is consisted by settlements A and B. They both have the same population (1000 people each). Each settlement was ...
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4answers
4k views

Heat map / Density map from dynamic points table in MapServer (GeoServer)?

How can I create a heat map (some would call a density map) from a points layer in MapServer (or GeoServer)? (preferably able to choose Interpolation method, NN, IDW, etc and color map with a ...
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2answers
181 views

Quality estimation of a spline interpolation with barriers

I interpolated the age of minerals for the Inner Tien Shan mountains (Kyrgyzstan) using the ArcGIS tool "spline with barriers". I use ~ 200 points for my interpolation. The barrier that I use is a ...
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1answer
297 views

Automating calculation of Population Density in Census Tracts?

I am quite new to Python and I am attempting to practice by making a simple program with ArcGIS. I wanted to make a script that automated the calculation of population density of selected census ...