Spatial Analysis means to manipulate geographic data to extract new meaningful information.
Interpolation is one of such geostatistical methods in which we use known values at sampled points to generate a continuous surface giving us prediction of values at unknown points.
IDW is an interpolation technique in which values of cells are predicted by averaging known point values while processing each neighborhood cell. Points which are closer to the estimated cell have more weightage in the averages.
IDW is preferred over Kriging in situations when sampled points are densely distributed over the surface.
How to perform Spatial Interpolation in ArcGIS:
1. Open ArcGIS.
2. Add XY data in ArcMap. In this case, we have an Excel spreadsheet of Monthly Average Precipitation Data in .XLS format.
3. Convert XY data to Shapefile (.shp format).
4. Add boundary over data.
5. Select points which lie within the boundary.
6. Export selected points to new Shapefile.
7. Search for the IDW tool within the Interpolation toolset inside Spatial Analyst toolbox.
8. Choose the column of known point values as Z value field.
9. Mask the output of Raster Analysis to the given boundary in the Environments Settings.
The Interpolated surface is obtained which can also be exported as a Raster Dataset for further analysis.
3 окт 2024
