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Digital Elevation Models (DEMs) and their derivatives are routinely exploited for a wide range of planning and engineering applications such as land reclamation, calculation of cut-and-fill requirements for earth works or to determine other relevant geomorphological landscape parameters. The advent of computer (digital) manipulation of elevation data has opened up great possibilities for studying the geometry of our land surface in relation to physical factors such as climate, vegetation, soils and geology. This paper is concerned with the generation, testing and validation of DEM and its derived terrain parameters viz., contours, drainage pattern etc. using IRS-1C stereo pair over a part of Alwar district, Rajasthan, India. In particular, it reports on the results achieved using indigenously developed stereo -processing software along with standard GIS and terrain analysis package to derive DEM and associated terrain parameters of the study area. The results are encouraging when compared with Survey of India topographical maps at 1:50,000 scale in terms of point to point accuracy of DEM, data quality evaluation of orthoimage and higher order drainage delineation.

Hydrological parameters have vital role in civil engineering, infrastructure planning and natural resource management. Since the last one and a half-decade their extraction using the High-resolution satellite stereo data has been very helping and less time consuming. In the earlier times, the ground surveys use to take a lot of time to cover a small area. Whereas with the availability of high accuracy Digital Elevation models from satellite stereo data one can extract these parameters with ease and good accuracy. During last one and half-decade vast experience has been gained in techniques of processing stereo data acquired from space. This paper deals with the extraction and validation of hydrological parameters from digital elevation model (DEM) derived using CARTOSAT-1 stereo data. In this paper two sub-watershed, one in Chamoli, Uttaranchal and other in Shimla, Himachal Pradesh were selected, A detailed morphometric analysis of the derived drainage network from the various sources and using various algorithms has been carried out. The parameters like stream order, stream length, bifurcation ratio, length ratio etc., have been used for comparison purpose.