Development of reservoir module for a distributed conceptual hydrological model

Many reservoirs have been built throughout the globe to satisfy the various water demands and control floods. To represent the reservoirs in hydrological modelling, a reservoir module is developed based on the Concept of Storage Zoning (CSZ) and implemented in a newly developed National Hydrological Model-India (NHM-I). The developed reservoir module is calibrated and validated independently for the Sardar Sarovar dam over 2010-2014 and 2015-2020. Results show that the module can satisfactorily simulate the trend and temporal patterns of water levels and spills with observed inflows. The Nash Sutcliffe Efficiency (NSE) value is estimated as 0.90 and 0.91 for reservoir water level and 0.87 and 0.86 for reservoir spill-over during calibration and validation. Further, the integrated NHM-I model with the reservoir module is calibrated and validated for another catchment (Panchet catchment) in Damodar valley, India having Tenughat and Panchet reservoirs. Results demonstrate that the integrated model captures the reservoir inflows, outflows and storage levels satisfactorily with NSE values of 0.64, 0.89 and 0.88, respectively. Also, the model simulation results with and without the reservoir module show that the model performance improved by including the reservoir module. The integrated model will help assess the management practices adopted in a reservoir-regulated river basin for effective water management.

Automated summary

A reservoir module based on the Concept of Storage Zoning (CSZ) has been developed and implemented in the National Hydrological Model-India (NHM-I) to accurately simulate reservoir water levels and spills. The module shows satisfactory results in simulating the Sardar Sarovar dam and the Panchet catchment in India, improving the overall performance of the integrated model. The integrated model can assess the management practices in reservoir-regulated river basins for effective water management.