ANALYSIS AND MODELLING OF SURFACE WATER QUALITY IN RIVER BASINS A DISSERTATION SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF THE DEGREE OF MASTER OF TECHNOLOGY (RESEARCH) IN CIVIL ENGINEERING WITH SPECIALIZATION IN WATER RESOURCES ENGINEERING By MRUNMAYEE MANJARI SAHOO Under the Supervision of DR. K C PATRA and DR. K K KHATUA DEPARMENT OF CIVIL ENGINEERING NATIONAL INSTITUTE OF TECHNOLOGY ROURKELA-769008 2014