Global DEM and country borders

Question

I am trying to split up the world into 2 categories based on elevation (below 2000m and above 2000m) while still including a country identifier. So in the end, I would like to have 2 types of units (low areas and high areas) for each country in the world, then I will use Spatial Analyst's Zonal Statistics to calculate the mean values of other rasters of interest in my defined areas. Does anyone have a suggestion for how to do this?

My data: - 16 DEM tiles for the world - 1 country borders shapefile

I am struggling with:

1)...working with all the DEM data at once on a global scale because I have been reading the mosaic-king across UTM zones distorts the data.

2)...whether my final units should be in raster form/ file geodatabase grid. I have heard that I should work in a file geodatabase and forget trying to have my final units be in shapefile form.

I know how to reclassify and have been successful at obtaining a raster with only two categories of elevation for each DEM tiles separately (above and below 2000m).

Any advice would be greatly appreciated, Liz

Answer 1

What you want to do, is quite easy. The high level steps can be as follows:

1. Using Raster calculator or the Con geoprocessing tool, reclassify the raster into three classes: null for oceans/water, 1 for below 2000 m and 2 for above 2000m.
2. Using Raster to Polygon tool, create a featureclass from this raster.
3. Intersect the output of 2, with your countries shapefile.
4. Once you have the output of 3, use Summery Statistics, to calculate the required statistics. You'll get a table with the required output.