How to Select a Grid cell and Exact values from it?

Discussion created by witgis on Apr 10, 2014
Latest reply on Apr 14, 2014 by witgis

Like • Show 0 Likes0
Comment • 4

Hi,

I would like to know how to select one grid cell and extract values from precipation and evapotranspiration raster data sets (GRID format). I am also using a world shapefile which contains the names of countries, area and their respective population.

Any assistance would be greatly appeciated.

Thank you.

Outcomes

4 Replies

GSCUser85 Apr 10, 2014 10:47 PM
What are you trying to do?
In ArcMap, the identify tool will return the value of anywhere you click on if you just want to see that.
In arcpy there is a GetCellValue(X, Y) function which will programmatically do a similar thing.
You could also create a set of points and use Sample to get the values at each point.
Cheers, Neil
Like • Show 0 Likes0
Actions
witgis Apr 11, 2014 8:11 AM
Hi Neil,

Thank you for your reply. Let me give you a better idea of what I am doing. Its a Water Resource Assessement Exercise. I was given the following data: 12 rasters with monthly mean daily precipitation (Prec) and 12 rasters images with monthly mean daily evapotranspiration(ETo) of the study area Bulgaria; a polygon of Bulgaria; Global raster of annual mean precipitation in geog coordinates; Global raster of annual mean precipitation in geog coordinates; and a Polygon layer of the world i.e the country borders in geographic coordinates.

The exercise has several questions which I have managed to answer most of them. However there is one question that require to "choose one grid cell and extract the monthly values of ETo and Prec respectively. Use these monthly values to plot the pattern of precipitation and evapotranspiration over a year for this specific cell. You can use Microsoft Excel or any spreadsheet program to do this.

My problem is - How do I select one grid cell and then extract the monthly values that are in different rasters?

I hope the above gives you a greater understanding of what I would like to accomplish.

Thank you.
Like • Show 0 Likes0
Actions
GSCUser85 Apr 13, 2014 10:22 PM
Well the manual version would work.
Get all the images into ArcMap, make sure they are visible, ticked on in the toc.
Use the identify tool with the option "visible layers", then write all the values into a spreadsheet.
Spatial Analyst's Sample tool would do they same thing, with a point layer with only one point in it.
Cheers, Neil
Like • Show 0 Likes0
Actions
witgis Apr 14, 2014 3:25 AM
Hi Neil,

With your guidance I created a sample point using the Batch Point Generation tool. I used the Sample tool in Spatial Analyst and input all the rasters for the precipitation data and used the new sample point created as the input location. I did the same thing also for the evapotranspiration data. With the two tables, I was able to produce a graph for monthly precipitation vs reference evapotranspiration (ETo) for a normal year for the sample point.

Thanks for your help! I really apprecaite it.
Like • Show 0 Likes0
Actions

GeoNet

The Esri Community

How to Select a Grid cell and Exact values from it?

Outcomes

Related Content

Recommended Content