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I have a point shp file of 445 points around the globe, that i need to create buffer-zone of 10 km around each point, the points shp file is in wgs1984 geographic coordinate and wgs1984 platte carre as projected coordinate system. Every time i create the buffer zone it gives me a HUGE circles above each other that cover the area of whole points together and more!. Does anyone knows why is this happening? enter image description here

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    I suspect you are inadvertently buffering by 10 decimal degrees instead of 10 km. Would you be able to edit your question to include precise details of the parameters you are entering on the tool dialog when you perform the Buffer, please? – PolyGeo Jan 10 '15 at 19:56
  • i entered 10 kilometer in the tool dialog .... – Nour Jan 10 '15 at 20:11
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    Restart ArcMap and Load Just "ONE" Layer that is Point layer wherefrom you will make buffer. Then run buffer analysis. – SIslam Jan 10 '15 at 21:06
  • I have also tried restarting and still getting the same result!! – Nour Jan 11 '15 at 15:37
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ArcGis attempts to project your data when doing a buffer in inappropriate units, this works for smaller datasets, it cannot do this if the points are dispersed all over the globe as it can't pick one to suit the whole dataset.

You are going to need to do each point (or cluster) individually, projecting to an appropriate projected coordinate system. For example this image illustrating how the earth distorts:

enter image description here

Australia is the same size as China and it's much worse at the poles!

Kilometres is not a valid measurement in geographic coordinates as the conversion depends on which part of the globe the point is, thus the data needs to be projected to a metre based coordinate system (UTM, Conic..) but you cannot project everything into the same projected coordnate system (it just doesn't work that way). After buffering project back to geographic if you need it in geographic. Note, your circles will become ovals.

If you need circles of approximately 10km in geographic coordinates you will need to find out what the conversion is at each point, insert that as an attribute and buffer by attribute... this will not be perfect by any means.

Which method you use depends on the weight you put on accuracy vs visual appeal.

If you look in your Arc install location reference systems folder (for example: C:\Program Files (x86)\ArcGIS\Desktop10.1\Reference Systems) there is a shapefile called UTM which you can intersect with your points to divide them amongst the valid UTM zones for projection (use Intersect or Spatial Join) then select the points by each unique ZONE_ID and project/save as and buffer then create an empty feature class in WGS84/Geographic and append the buffers (this will project them at the same time) to merge. Note, if you want attributes to be copied ensure that the empty geographic shape file has the required fields.

  • Thank you so much @MichaelMiles-stimson , appreciate your help, i did followed your instructions, after intersecting the UTM shp with the points i got only two values in the ZONE_ID field, however, i selected one made a layer, and created buffer for it, still got the same result of the huge polygons. i also tried to do it on one separate point to try and still also the result was the same! – Nour Jan 12 '15 at 9:39
  • After selecting the points by Zone_ID you need to project or save as that UTM zone projection; UTM projections are split at the Equator so you may need to split again if you have a mix of north/south points. It seems that ArcGis is getting flustered at project-on-the-fly... also, please ensure that the spatial reference of the points is set to Esri standard WGS84 (layer properties or define projection) not some text that roughly equates to WGS84; using the Esri spatial reference may help ArcGis understand the requirements. – Michael Stimson Jan 12 '15 at 21:21
  • @Nour Please consider up-voting or clicking the check mark to accept the answer if it has solved your problem. – Chris W May 1 '15 at 23:03

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