Question: Why would you create more than one spatial index on the same spatial column in SQL Server 2008?
Answer: To set different tessellation parameters
Explanation: The primary reason for creating multiple spatial indexes on the same spatial column is to apply different tessellation parameters to the index. The tesselation process fits the data in the column into a grid area, allowing faster queries. Different parameters might result in grosser or finer grids applied.
Note: The Question is taken from SQLServercentral.com.