ARC GIS Weighted overlay

[mshakir]

Hi everyone,

I am doing an analysis for suitable school site selection now i am in the final stage, i have reclassified layers of ,

roads,

settlements,

water channels,

slope,

already existed schools,

and my landuse map,

Now i want to give them a proper weightage and % of influence in the final site selection, could anyone help me how to give the above layers a proper % in the final step.

Thanks in advance

[3dbu]

i present a clue how to make the weightage in %

Roads,(10)

settlements,(40%)

water channels,(5%)

slope,(25%)

already existed schools,

and my land use map,(20%)

 

the principal effect over the change land use is the settlement and roads, after have great influence the slope and and use respectively ...hope be usefully, regards

[sanzida]

tools are available in arcgis,,,,,,,,,,,,,,,,,,,,go spatial analyst then overly tool and then weightage overlay, in this interface you could be able to set all the value whether its weight or influence..

[yousef2233]

1 - the way you find weights 

    you can find weights of your layers with MCDM methods (multi criteria decision making) like AHP

2 - the way you weight layers

    simply after creating raster files from featureclasses, normalize them (put values of all rasters between a specified range)

    normalizing can be obtained via Raster Reclassification

    use raster calculator for final step (for example: [dist2existingSchools_norm]*.3 + [slope_norm]*0.5 + .... ) 

 as sanzida said, (Weighted Overlay / Weighted Sum) is the same