Landform, drainage pattern, slope, soil, vegetation and land use/land cover, all of which control surface runoff and peak flow, can be evaluated and mapped reliably and reasonably through Landsat Thematic Mapper (TM) false colour composites of the post-monsoon season. Runoff curve numbers (CN) determined from those data predicted the runoff depth and peak flow with a coefficient of determination of 0.970 and 0.863 respectively; thereby indicating that, in terms of accuracy, speed and cost, the Landsat TM data are of great significance for estimating surface runoff via the SCS model in the arid environment of northwest India.