Different area calculated between shapefiles and geodatabase

Question

Hi. Our company recently purchased the ArcGIS Server. We migrated all of our GIS data from the native Shapefiles format to GeoDatabase. the problem, we get 2 different areas - hectares calculated in shapefiles are different than those calculated in the GeoDB. Does anybody have this problem? is this normal? because we have to explain the difference to our management.

Thanks.

LouiseDuffy2 · Answer

Just wondering if you have gotten an answer to this.

lawrencegalakong · Answer

hi dan. i think i know what the problem is. we're taking area (hectares) only to 2 decimal points, and when ArcGIS calculates the area, it takes the value to 2 decimal points without considering the value of the third decimal point; 2.1588 should be 2.16, but it returns 2.15. Please see the image below: -

[ATTACH=CONFIG]22823[/ATTACH]

"HECTARES" -> stores the area calculated in shape format using the Calculate Geometry function
"HA2" -> stores the area calculated in geodb format using the Calculate Geometry function
"HA3" -> stores the area calculated by dividing "SHAPE.STArea()" with 10000

is there any workaround for this? thanks.

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DanPatterson_Retired · Answer

create a feature of known dimensions (ie a rotated rectangle) and save it in the various formats you work with and calculate the coordinates, perimeter and area of said feature.  i have never found shapefiles to yield erroneous dimensions in either location, perimeter or area