ANNOUNCEMENTS
This thesis attempts to assess the impact of climate change on the hydrological regime of Chenab basin, one of the main tributaries of Indus River System. Chenab is an ungauged basin in upper reaches and has significant area under snow and glaciers, thus making this basin a choice for understanding the hydrological regime, role of snow and ice melt and changes expected in hydrology due to projected climate change. Any alteration to the river regime would affect the dependent users in the basin. To understand this complex water availability and demand dynamics, baseline assessment of hydrological processes of the basin and water demand from the basin was undertaken. Semi distributed HBV model was used to simulate discharge and other key hydrological processes and simulated results showed that ice and snow melt contribution is around 49% to the annual average river discharge. PODIUMSim model was used to understand the demand from various users, where agriculture is the major demand sector, but still the basin is a surplus basin. All the hydropower projects in the basin are run of river projects which need consistent water supply. To assess climate change impact on river hydrology, CORDEX data was used. Mann Kendall trend analysis indicates that in the long run, the basin is expected to witness higher temperature but no significant change in precipitation. Hydrological modelling with projected temperature and precipitation data indicates that discharge would increase throughout the century, however, the proportion of monsoon discharge would decrease in future getting compensated by increase in proportion of pre-monsoon and postmonsoon discharge. These seasonal changes in discharge would affect two main users in the basin-agriculture and hydropower sector. Agriculture sector is already witnessing the effects of changing climate and horticultural crops are worst hit in the region. Similarly variation in seasonal discharge affects the sustainable operation of hydropower projects and they would be vulnerable to expected changes in the hydrological regime of the basin. This study lays foundation for developing water management plan for the basin which will not only help in informed decision making for investment and infrastructure development but also for developing adaptation strategies.
