# How do I calculate the openness index for urban expansion?

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07-20-2019 09:58 AM
New Contributor III

Hope everyone is well.

Please, I need your help to calculate the openness index for urban expansion using ArcMap if possible.

I do not have any idea how I can do it? what is data that should I use? equations and tools?

Any help, explanation, examples and procedures that you can advise me, it will be highly appreciated.

Sincerely,

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1 Solution

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MVP Regular Contributor

To do this using GIS you will need temporal data ( tables, vector data, imagery, etc.) in some form for the area you are trying to study urban expansion.  The type of data will determine what tools and processes you can utilize in your GIS application. Can you please provide more information pertaining to what data you have available and the approach you are considering or have attempted, the specific problems you may be encountering, etc.?

Here is a link pertaining to using GIS to Understanding and Measuring Urban Expansion

3 Replies
MVP Regular Contributor

To do this using GIS you will need temporal data ( tables, vector data, imagery, etc.) in some form for the area you are trying to study urban expansion.  The type of data will determine what tools and processes you can utilize in your GIS application. Can you please provide more information pertaining to what data you have available and the approach you are considering or have attempted, the specific problems you may be encountering, etc.?

Here is a link pertaining to using GIS to Understanding and Measuring Urban Expansion

New Contributor III

Dear Lance Cole,

It is a new project. I have to deliver it to my manager as soon as possible.

Regarding data, I have two raster images (satellite images) and two vector maps with different dates and it has the same region.

I have to find:

-The openness index is the average share of open space pixels in the
walking distance circle around each built-up pixel in the city;

- The walking distance circle is a circle with an area of one square
kilometre around a given built-up pixel;
- Urban built-up pixels are pixels that have a majority of built-up
pixels within their walking distance circle;

For this region.

Please, I would like to know the tools and steps to do this work by ArcMap.

I will highly appreciate your help.

MVP Regular Contributor

In your vector data, to you need to have green/open space areas and built-up points or areas delineated?  Both of these would be needed to even start a analysis.  If you are looking for change over time you will need this data over multiple time periods.  If you are looking only for current data you can work only with your most recent data.

Please also look at Measuring access to parks link.  This is not a specific example for openness index but the process would be similar.  It does require access to the special analysis tools in ArcMap.  You would basically be constructing 1 Sq Km buffers around your buildup point/ area and determining the amount of open space within that area.  You can also convert your vector data into a surface(s) representing buildup points or areas and open space areas then perform a cost distance analysis on the surface(s)

You can can look at the following tools depending upon your available software.