Topo to Raster

[BenjaminMittler]

For a hydrology project i am working on i was given a very detailed contour line file as my set of data to work with. As we know, all of the spatial analyst hydrology tool require a raster set to work with. Since the contour lines are so detailed when i try and use the topo to raster tool it says that their are to many points to convert. For the mean time i have been creating a TIN from my contour lines and then converting this to a raster however, since my initial raster wasnt really a uniform shape when i create the tin it interpolated very large areas which largely skew my hydrology analysis.

I know that their is a simplify line tool i could use to possibly use the contour to topo tool but unfortunately my agency doesnt have a license for this.

Does anyone have any better way of preserving data while converting my contours to a raster
(contours at some points are .5 feet.)

Thanks,
Ben

[ShaunWalbridge]

I'd start by trying Topo to Raster with the optional Extent parameter set to a limited area within your full dataset, it won't try to interpolate contours outside the extents you've set. Doing that multiple times over different pieces of your full set should work. Similarly, you could try using something like the Dice tool to break up your contours into smaller areas, and run the conversion step on each of those pieces, just watch out for edge effects (where the interpolation tries to match to the new artifical vector boundary).

If neither of those work, I'd think about thinning the input dataset (removing vertices that are close to their neighbors and don't vary much) and see if you can effectively reduce the point volume without compromising the surface structure.

cheers,
Shaun