I need to download a DEM in WGS format for Nepal ( around 86 degrees longitude and 27 degrees latitude), that can be exported to a GIS as raster for analysis. Does anyone know of any good, free data source?
If you go to the Earth Explorer web site you can download several DEMs. For Nepal they have the 30m AsterGDEM and the 90m Void Filled SRTM. The 1 arc second (30m) SRTM is not available yet (12/12/2014) but I believe it should be ready in the near future
Theres SRTM data available. See https://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Mission for more information.
Note that SRTM hat a ground resolution of approx. 30 or 90 meters ( 1 and 3 arc-seconds, respectively). That is probably the highest-resolution free dataset available.
For more detailed DEMs you should contact local Nepali governments/universities.