1. Associate Professor, Dept. of Hydrology, Indian Institute of Technology Roorkee, Roorkee-247 667, India. E-mail: p_erumal@yahoo.com
2. Scientist, National Academy of Agricultural Research Management (ICAR), Rajendranagar, Hyderabad-500 407, India; formerly, Research Scholar, Dept. of Hydrology, Indian Institute of Technology Roorkee, Roorkee-247 667, India (corresponding author). E-mail: bsahoo2003@yahoo.com