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

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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 ...
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1answer
998 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
78 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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24 views

Density Heat Maps using R

I recently have been reading about mapping GIS information in R. I have 2 data sets from work. Without going into too much detail, the first data set is a list of failures with Geo Codes, the second ...
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2answers
41 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
48 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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30 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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63 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
3k 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 ...
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518 views

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

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
208 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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88 views

Search Radius for Line Density

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
61 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 ...
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3answers
1k 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
27 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 ...
4
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76 views

Interpolating species data from sample points in a small area

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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4answers
1k 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 ...
3
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2answers
91 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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2answers
707 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
165 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 ...
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1answer
155 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 ...
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2answers
77 views

How do I create zones using location features? [closed]

I have a list of rock art sites with a recording of every image within each site. For example, Site 1 has 4 kudu, 1 lion, 3 males and a locust; Site 2 has 2 leopards, 1 elephant and 3 giraffes; Site 3 ...
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2answers
216 views

Identifying clusters of points within a given distance

So I have a database of lats/longs representing incidents occurring on or near roadways. My goal is to identify the street block areas with the highest number of incidents in the database. I don't ...
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222 views

Trying to Create a Global Choropleth Population Density Map then add Biodiversity Level

I am trying, quite unsuccessfully, to create a global choropleth population density map for a specific 120 countries, using ggplot2. Once I have created this choropleth map, I want to add number of ...
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81 views

Statistically compare two density maps?

I (will) have a modelled distribution and an observed distribution of animals. If I were to interpolate these position datasets to reflect some density distribution (perhaps using a kriging ...
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2answers
117 views

City density in GIS

There's a cite calles http://map.vmr.gov.ua/ in which each house has a type (for living, offices etc) and number of floors. I want to find out city density - i.e. to assign certain amount of people ...
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1answer
488 views

Creating contours with meaningful values from point data

I recently obtained a CSV containing the locations of all recorded bicycle accidents in Boston over the past few years. As an avid cyclist, I'd like to create a simple contour map that draws attention ...
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4answers
1k 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
564 views

Python problems with select by attributes and user input

I am attempting to create a tool where the user can input a census tract number within the city of Plano (there are 77 tracts) and it ultimately creates a map layout showing the population density. I ...
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2answers
119 views

Count the area of rasterdata in specific shapefile polygons (residential density in different districts)

I'd like to count the exact area of three different residential classes (low, medium, high) by district of a shapefile which contains 225 districts. like: district 1 has: XXX sqm low, XXX sqm medium, ...
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365 views

How to fill in the parameters for kernel density estimation?

I am desperately trying to calculate animals home range with kernel. Unfortunately, the result is obviously incorrect and I cannot identify my mistake (I would like to post a screenshot but its not ...
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190 views

catchment delineation

I am trying to use qgis to delineate between three sub-sub-catchments. I have contour shape file of 20 meter height. Sub-catchment is about 12 square kilometers area but consist of three ...
5
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1answer
279 views

Adding kernel density output to map with ArcPy

I am trying to emulate the behavior of the Kernel Density tool from the ArcMap 10 GUI in a script; in other words, I want to calculate the density of a dataset, and add the visual result to a map. If ...
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1answer
95 views

V.kernel not working correctly in grass-6.4.2

I am using grass-6.4.2 for generation of heat maps of crime data. For testing purpose, I created a vector layer from my places shapefile which is a point data.The places shapefile contains more than ...
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1answer
552 views

How to create a Human Trafficking Heatmap in QGIS?

I'm trying to create a heatmap with about 325 points distributed around the city of Houston. (FYI Houston is a major human trafficking in the US: a title shared with LA and Atlanta depending upon ...
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50 views

how can i plot news stories to show how many stories include each country on a map of the world

We have a table that shows the number of news stories that include particular countries over a set period of time there are three news channels that we have this data for and we would like to show/ ...
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243 views

How to calculate the density of settlement per 100 square kilometers?

I have a point shapefile representing settlements. I want to calculate the density of settlement per 100 square kilometers. Should I use point or kernel density? I am working with ArcGIS. Is there any ...
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1answer
3k views

Dot Density Maps in QGIS?

Is there a 'friendly' way to create dot-density maps, where a polygon attribute data defines the number of dots (e.g. 1 dot = 100 ) using QGIS 1.7+? I say friendly because after a couple of hours ...
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2answers
152 views

summing up over an area based on a 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 ...
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1answer
1k views

How do you use GRASS's v.kernel?

I am flummoxed on how to use GRASS's v.kernel. I have a vector layer of around 2.5 million points. I want to make a heat map using v.kernel to show concentrations, since I have variable instances ...
5
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1answer
307 views

Finding nodes with QGIS

As part of work in statistical mapping for school, I need to use QGIS to find the spatial extent of commercial nodes. A node is defined for this exercise as a zone of 75m in diameter where the ...
3
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2answers
321 views

Determine density or cover from a raster layer that has been clipped by a polygon

I am a very new GIS user using ArcMap 10. I have a raster layer of tree canopy that I have clipped so that the layer is in a polygon that is a circle with a 2km radius. I have done this for four ...
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0answers
167 views

Is there a tool that tells how many features there are within a set distance in ArcView?

I'm looking to create a raster, in ArcView, that represents how many features (either points or polygons) are within a certain distance from any given location within a study area. I know there must ...
5
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1answer
975 views

How to produce density map in square kilometers?

I have a shp file with the location (lat, lon) of lightning spatial distribution. I want to produce a density map of lightning occurrence per square KM. I used density point function and I don't know ...
6
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2answers
463 views

How to redistribute population data using Python in ArcGIS?

I am trying to redistribute population data from census centroids among to housing density.Would you please help me to do that? I do have census area centroids (points) and the boundaries belong to ...
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6answers
1k views

How do I make a heat or Choropleth map that uses polygons in QGis?

I've been playing around with the heatmap plugin for QGIS and I am wondering if it is possible to make heatmap with using a similar plugin/tool that uses polygons as well as points? I would like to ...
6
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2answers
303 views

How do I compute v.kernel maps in less than 16 hours?

I am using the GRASS GIS 6.4.2 bundled with QGIS 1.8.0, using a PostGIS dataset exported via v.in.org.qgis from QGIS, to create kernel density maps. The layer has 738,288 points. My problem is the ...
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1answer
3k views

How to do Kernel density analysis in QGIS 1.7?

Do someone have some suggestion? We would like to tray Kernel Density analysis as we did with ArcGis using QGIS?
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6answers
5k views

What's the best way to produce a density map from weighted points in QGIS?

I'd really like to repeat the functionality of the ArcGIS Kernel Density tool - how could I do that? I would like to limit answers to easy-to-install free-and-open-source software – i.e. QGIS ...
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3answers
1k views

Is population density considered continuous data and why?

Population counts are typically referred to as discrete or quantitative data. Why is population density a continuous data type when it is typically measured for aggregate areas such as census tracts ...