SAMPLE PROCEDURE FOR GENERATING PERCENTAGE RASTER DATASET

1) Add "Landuse" data layer on your project.

2) Right click on "Landuse" data layer and "open attribute table".

3) By using the "Select By Attributes" tool, select land cover classes with "Landuse-ID = 7".

4) By keeping this selection, right click on the data layer and select "Data  Export Data" for exporting the selected polygon features into a new shapefile.

5) Convert this landcover-7 vector polygon layer into a grid file of 100-m resolution (ArcToolboxConversion ToolsToRasterPolygonToRaster) (Value Field: Landuse-ID, Cell Assignment Type: Cell Center, Cellsize: 100 (in screen units)).This grid will be your reference grid.

6) Check the row and column numbers of the Luse7grid (Right click on the layer, open properties, record the number of rows (NR) and columns(NC)).

7) Now generate a fishnet layer in vector polygon format (ArcToolboxData Management ToolsFeature ClassCreate Fishnet) (Template extent: Luse7grid, Cell Size Width: 100, Cell Size Height: 100, Number of rows: NR, Number of columns: NC, Create Labels: checked)

8) Create intersection polygons from the landcover-7 and fishnet vector polygon layers (ArctoolboxAnalysis ToolsOverlayIntersect) (Input layers:(1) fishnet (2) landcover-7, Join Attributes: All, Output Type: Input).

9) Right-click and open attribute table of the intersection vector layer. Add a new field called "ALAN" onto the table. You may select double data type, with precision 10 and scale 2 (i.e. 2 decimals).

10) Clean any selection if any and then select the field "ALAN" by left-clicking from the field heading. Then right-click and calculate geometry where the "area" computation will be selected.

11) Now generate another field called "PERC" for computing the percent coverage rates.

12) Again select the new field by left-clicking and then right-click the field heading for selecting the "Field Calculator" function. Copy the following equation for computing the percent shares:

PERC = ([ALAN] / (100 * 100)) * 100

13) Right-click the fishnet labels layer and select "Joins and Relates". Join the table of the intersection layer with the table of the fishnet labels. Use common ID field as the key field for matching between the records.

14) From ArcToolboxConversion ToolsToRasterPointToRaster, convert the fishnet labels into raster format by using the right-most "PERC" field as value field.

15) Change the colouring of the final grid layer by righ-clicking the layer and selecting its properties.

GOOD LUCK...