Design, operation and management of dams and reservoirs is governed by the discharge and sediment load and of a river. Despite being among the largest river basins in the world, sediment–discharge ratings of the Ganga River has received little attention from the researchers probably due to lack of data availability. The present paper aims at analysing the sediment and discharge rating characteristics at 15 gauging stations of the Ganga River. Significant scatter exists in the sediment–discharge relationship during monsoon season and as such a single rating curve was not found adequate to define the sediment–discharge relationship. To address the scatter in sediment–discharge relationship, a novel monthly index number was introduced in sediment–discharge rating curve equation. The rating equation parameters were estimated using a generalized reduced gradient (GRG) solver available in MATLAB. Qualitative as well as quantitative comparison of single rating curves with monthly sediment rating curves reveal that monthly sediment rating curves were in better agreement with the observed data as compared to the single rating curve. Significant spatiotemporal variation in sediment and discharge and inverse correlation between sediment rating parameters exist in the Ganga River. It was also observed that the scatter in stage–discharge relationship was less as compared to the sediment–discharge relationship. No consistent relationship could be found between rating curve parameters and the magnitude of discharge or season. The concept of index number can be applied to other rivers where significant monthly or seasonal scatter in sediment–discharge relationship exist.

大坝和水库的设计、运行和管理受河流的流量和泥沙负荷控制。尽管是世界上最大的河流流域之一，恒河的沉积物排放等级几乎没有受到研究人员的关注，这可能是由于缺乏可用数据。本文旨在分析恒河15个测站的泥沙和流量等级特征。季风季节沉积物-流量关系存在显着的分散性，因此发现单一评级曲线不足以定义沉积物-流量关系。为了解决沉积物-流量关系的分散问题，在沉积物-流量等级曲线方程中引入了一个新的月指数。使用 MATLAB 中可用的广义缩减梯度 (GRG) 求解器估计评级方程参数。单一评级曲线与月沉积物评级曲线的定性和定量比较表明，与单一评级曲线相比，每月沉积物评级曲线与观测数据的一致性更好。恒河中存在显着的沉积物和流量的时空变化以及沉积物评级参数之间的反相关。还观察到，与沉积物 - 流量关系相比，阶段 - 流量关系的分散较小。在额定曲线参数与排放量或季节之间没有发现一致的关系。