Codification System:-

 Alphanumeric system has been followed to codify the different hydrologic units. Different stages of delineation have been codified in a systematic way alternating with Arabic numerals, English capital and small alphabets as follows:

v Water Resources Regions: 1, 2, 3, 4, 5, 6

v Basins: A, B, C, D, E, F ………

v Catchments: 1, 2, 3, 4 …………

v Sub Catchments: A, B, C, D, E, F, G …………

v Watersheds: 1, 2, 3, 4, 5, 6……9

For example, watershed code 5D5A6 connotes:

v 5: Region (Rivers flowing into Arabian Sea)

v D: Basin (Narmada)

v     5: Catchment (Tawa confluence of Marble rocks left bank of Narmada)

v A: Subcatchment (Tawa confluence to Denwa)

v 6: Watershed (Sonbhadra)

This Watershed Atlas of India (WAI) has been prepared on a 1: 1000K scale and contains a total of 76 map plates. Positional reference of the 76 map plates (Key to Plates) is depicted in fig. 8.