length

[adnan0001]

hi friends

i have made soil , geology and geomorhology using empty shapefileand i want calculate the length in km2

after reclassingthese in to 5 classes when am going to calculate length using calculate geometry is not highlighted..

can any1 plz tell me how it to be cal culate...

note:

i haven't made personal geodatabase direct i have taken shape file and digitised

Edited June 8, 2013 by adnan0001

[EmperoR]

first, you must define the projection first, for your new data

to make calculate geometry available, you need UTM projection

regards,

[adnan0001]

projection everything is set but problm is the same similar with other maps

here is snapshot plz check

https://www.dropbox.com/s/4o9mk9y0aoxzf8v/snapshot.doc

plz help me for the solution its very urgent

[yousef2233]

Hi its very easy,

1) convert it to Vector based and use Calculate Geometry

OR

2) multiply Count * area of your raster cell size (it gives you area of course )

[adnan0001]

hi brother (yousuf)

If am not wrong,actually it was in vector, i converted it to raster to classify them in 5 categories but am unable to see polygon only value,count are been seen..accoding to ur statement in the previous msg dat

multiply Count * area of your raster cell size

but area from where to get

plz explain in detail ...will be thankful to u...am pending with thematic maps

plz help

[EmperoR]

really weird, if its a vector and projection in UTM , it should be able to use calculate geometry

if you don't mind, you can share a data example that have those problem, let us take a look

regards,

[yousef2233]

1 - Right click on your raster

2 - Properties

3 - On the source Tab

4 - you can see Cell Size (X,Y)

[adnan0001]

here is the data which am facing the probm

https://www.dropbox.com/sh/fyx3kwwm1ea9fcm/qnSMzD9OWh

thanks

[adnan0001]

thanks

but if am calculating it am getting large area ex:

(count)9586*20*20=3834400

is it length or areA am unable to understand plz tel with ex

wil b thankful to u

[yousef2233]

the concept of raster

each raster consists of cells which are rectangle. the area of a rectangle = length * width

so the area of a cell = length * width = X * Y

you have 5 classes, in the table of content of the raster you have, it has been determined that every class has how many cell in there = Count

so, if you multiply Count of cells in each class in Area of the cell you will have AREA,

note that, the x and y are in meters or centimeter in order to correct calculating