Hydrological changes and its impact on water resources of Bagmati watershed, Nepal

Abstract

For long-term planning and management of water resources, future change in the pattern of landuse, water demand and water availability should be analyzed well in advance. The assessment of climate change impacts on the hydrological resources of a country is the most important assessment to be carried out, before planning any long-term water resources utilization program. Change in the hydrology of the Bagmati River is analyzed and its probable future implications are accessed. Trend analysis of seasonal flows and extreme events shows that monsoon seasonal floods are decreasing while other seasonal flows are constant. The magnitude of flood is decreasing but its frequency and duration are increasing. The hydrograph is shifting in time which is affecting water availability. In the changed scenario, hydropower production is likely to decrease in the future. Production of rice has decreasing trend while production of wheat has increasing trend. The proper modality of a water sharing agreement should be negotiated between the riparian countries Nepal and India before any conflict may arise, as the water volume is decreasing year by year. To address all the changing scenarios of the river hydrology an appropriate policy should be formulated for long-term water utilization.