1. Scientist (SS), Irrigation and Drainage Engineering Div., Central Institute of Agriculture Engineering, Bhopal 462 038, India.
2. Professor, Dept. of Irrigation and Drainage Engineering, G.B. Pant Univ. of Agriculture and Technology, Pantnagar 263 145, Dist. Udham Singh Nagar, India.
3. Professor, Dept. of Mathematics, Banaras Hindu Univ., Varanasi, UP, India.