GIS for Disaster Management

[KrupaliVijaykar]

Hello,
I am trying to work on a project where I need to find population data.

One layer has population data of villages (polygon layer of villages, with population in attribute table)
Another layer has a threath zone for a particular disaster (again a polygon layer)

I have to find the population data of villages, only which comes under the threat zone.. (ie. if a particular threat zone covers part of a village, only part of the population data should be the output & not the entire population)

Any suggestions, how I can select only part of population & not just display population of the entire village

Regards,
Kvijaykar

[JoeBorgione]

Hello,
I am trying to work on a project where I need to find population data.

One layer has population data of villages (polygon layer of villages, with population in attribute table)
Another layer has a threath zone for a particular disaster (again a polygon layer)

I have to find the population data of villages, only which comes under the threat zone.. (ie. if a particular threat zone covers part of a village, only part of the population data should be the output & not the entire population)

Any suggestions, how I can select only part of population & not just display population of the entire village

Regards,
Kvijaykar

When using population data in polygon form, you have to accept an assumption that the the population is evenly distributed across that polygon.  That may or may not be true, but it's just the nature of the beast.

Typically, the approach I have taken in such analyses is to add a field to the population polygon called Original_Area and calculate it to the area field.  Then comes the geoprocessing step;  either clip, intersect etc with the threat polygons.  The resulting population polygon has the NEW area calculated as well as the ORIGINAL_AREA added before the geoprocess step.  Now, add field called ADJUSTED_POPULATION and calc it this way:

(original_area / area) * population

You'll have a proportioned population.  Again, this works nicely as long as you can live with the evenly distributed population assumption.

Hope this helps-

[KrupaliVijaykar]

When using population data in polygon form, you have to accept an assumption that the the population is evenly distributed across that polygon.  That may or may not be true, but it's just the nature of the beast.

Typically, the approach I have taken in such analyses is to add a field to the population polygon called Original_Area and calculate it to the area field.  Then comes the geoprocessing step;  either clip, intersect etc with the threat polygons.  The resulting population polygon has the NEW area calculated as well as the ORIGINAL_AREA added before the geoprocess step.  Now, add field called ADJUSTED_POPULATION and calc it this way:

(original_area / area) * population

You'll have a proportioned population.  Again, this works nicely as long as you can live with the evenly distributed population assumption.

Hope this helps-

Thanks for the reply...

It was of great help!!!

U have any information about available softwares for disaster management (ive found one called Sahana Eden).

I am evaluating the available softwares & highlights of each.

Any leads would be of great help.

Regards,

Krupali