In general alphanumeric characters are used for coding the river system. In the present Atlas, while deciding the codification system, emphasis has been given for river names forming the sub-basins that can be easily understood and accepted at regional levels. The coding has been done in two steps. In the first step the code has been given to sub-basins and in the second step the watershed code has been defined. Sub basin code has been derived from the name of the river / stream forming the sub-basin. The code consists of four alphabets of river name in capital letters. In case of sub-basins having upper, middle, and lower categories the first three alphabets are taken for the stream name and the fourth alphabet refers to U, M, and L to represent the upper, middle, and lower respectively. For example Godavari Upper sub basins is coded as GDVU.
In the second step three numeric characters have been added to sub-basin code to represent the watershed numbers of that particular basin. Finally a 7 digit alphanumeric code has been used to represent a particular watershed. First 4 alphabets letters refers to sub-basin and the last 3 numeric characters specified to particular watershed. For example the watershed code “GVDU012 “ stands for the watershed “012” of Godavari Upper sub-basin. To the extent possible the watersheds numbering have been done from upstream to downstream of the river forming the sub-basin. The Basin / subbasin wise watershed coding along with the attributes is given in Appendix-I
The present “WATERSHED ATLAS OF INDIA” on 1: 250,000 scale is an attempt to provide a platform and base map adopting a simplified and easily understandable delineation approach as well as codification system, which will go a long way in providing a basic tool for assessment of groundwater resources, planning macro / micro-level developmental activities on watershed basis.

Basinwise

Watershed

Codes

Barmer