Nepal gis maps

It has been a challenging task to develop a seamless fine quality Digital Terrain Models (DTMs) for whole Nepal. Due to the lack of resources high quality images advanced computing devices and stereo photogrammetry was not used to develop the DTMs.  I have developed the DTMs from the interpolation of digitized contour lines. In the first step DTMs were stored in vector format as Triangular Irregular Network (TIN), in the second step the TINs were converted to raster format as TINGRID each pixel in those TINGRID raster maps contains the elevation data from the center of those pixel. In contour interpolation method data digitized from larger scale maps with closer counter interval yields the best quality DTM Taud et al., (1999), Deng et al., (2007). For this study the map scale and contour interval chosen meets the above criteria  as proposed by Deng et al., and fine seamless DTM’s were developed sheet wise to  region wise for whole Nepal. TINGRID raster maps were further used to develop, hill shades, slope steepness maps, slope direction maps, slope convexity/concavity maps and all those topographic features were  overlaid  with geologic maps, land use maps to understand and  interpret the relationship between topography, geology land use etc. (Tank Ojha Ph.D. thesis).

Digitized contours at 20 meter, 40 meter, 100 meter and 200 meter contour interval from published topo maps

Digitized  geological polygons draped over DTMs generated from digitized contours.

Digitized land use polygons draped over DTMs

Digitized rivers draped over DTMs.

 

Digitized roads draped over DTMs

Digitized villages draped over DTMs

Text Box: For detailed information please contact
Dr. Tank Ojha
Email: tank.ojha@cox.net

Text Box: Weird Spatial Relationships among People, Climate, Topography, and Geology in the Himalayan Region of Nepal


Tank Ojha, Ph. D. , Adjunct Professor
Department of Geoscience, University of Arizona, USA 
Consulting Geologist & Geo-disaster Risk Analyst, Geo-Information Specialist for Natural Resource Management  (Email: tank.ojha@cox.net, ojha@email.arizona.edu)