1. Visiting Fellow, Center for Theoretical Studies, Indian Institute of Technology, Kharagpur 721302, West Bengal, India.
2. Research Engineer, Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Cientificas, Finca Alameda del Obispo, E-14080, Cordoba, Spain.
3. Professor and Brahmaputra Chair, Dept. of Civil Engineering, Indian Institute of Technology, Kharagpur 721302, West Bengal, India (corresponding author).