Brahmaputra River Basin (BRB), the largest contributor of sediment load in Ganges–Brahmaputra–Meghna delta, is highly vulnerable to future climate change. Several studies assessed the effects of climate change of BRB on river flow but an assessment on sediment load has not been conducted. Changes in sediment load in the future need to be assessed to control and manage sediment flows in large catchments properly. The present study focuses on developing a hydrological and sediment routing model of BRB using the HEC-HMS model to estimate future sediment load together with the flow for the RCP 8.5 climate scenario. Modified Universal Soil Loss Equation and Engelund Hansen method of HEC-HMS have been applied for the sediment transport of BRB. The model has been calibrated using daily runoff for the period 1983–1996 and validated for the period 1997–2010, respectively. The uncertainty in the percentage change in seasonal sediment load during the pre-monsoon season is higher than that of the monsoon season. However, the contribution of the sediment load of pre-monsoon is very much lower than the monsoon season. The percentage changes in mean annual sediment load compared to the baseline period for the 2020s, 2050s and 2080s are 34, 67 and 115%, respectively.

布拉马普特拉河流域（BRB）是恒河–布拉马普特拉–梅格纳河三角洲最大的泥沙负荷贡献者，极易受到未来气候变化的影响。几项研究评估了BRB的气候变化对河流流量的影响，但尚未对泥沙负荷进行评估。需要评估未来泥沙负荷的变化，以适当地控制和管理大型流域的泥沙流量。本研究的重点是使用HEC-HMS模型开发BRB的水文和泥沙路由模型，以估算RCP 8.5气候情景的未来泥沙负荷和流量。修正的通用土壤流失方程和HEC-HMS的Engelund Hansen方法已被用于BRB的沉积物输送。该模型已使用1983-1996年期间的每日径流进行了校准，并分别在1997-2010年期间进行了验证。季风前季节的季节性泥沙负荷百分比变化的不确定性高于季风季节的不确定性。但是，季风前的沉积物负荷比季风季节低得多。与2020年代，2050年代和2080年代的基准期相比，年平均沉积物负荷变化百分比分别为34％，67％和115％。