Sensitivity analysis of CN using SCS-CN approach, rain gauges and TRMM satellite data assessment into HEC-HMS hydrological model in the upper basin of Oum Er Rbia, Morocco

• Published in: Modeling earth systems and environment 2022-11, Vol.8 (4), p.4707-4729
• Main Authors: Faouzi, Elhousna, Arioua, Abdelkrim, Hssaisoune, Mohammed, Boudhar, Abdelghani, Elaloui, Abdenbi, Karaoui, Ismail
• Format: Article
• Language: English
• Subjects: Chemistry and Earth Sciences; Computer Science; Earth and Environmental Science; Earth Sciences; Earth System Sciences; Ecosystems; Environment; Math. Appl. in Environmental Science; Mathematical Applications in the Physical Sciences; Original Article; Physics; Statistics for Engineering
• ISSN: 2363-6203; 2363-6211
• DOI: 10.1007/s40808-022-01404-8

Hydrological process modelling consistency is associated with long available gauged data and reliable parameters, which is often limited. Multi-sensors and satellite-based products are considered as an alternative, especially dealing with ungauged basins. In this study, a HEC-HMS hydrological model is used to test two rainfall dataset reliability (Gauges, TRMM product). The testing period is fixed for 2000–2011 to simulate streamflow generated at upper Oum Er Rbia basin. Dealing with soil information lack in the study, we implemented SCS-CN approach in its spatially semi distributed manner, adjusting CN, and comparing streamflow obtained by interpolated gauged and average TRMM pixels values, the model was calibrated to determine its accurate CN for the study area. In the calibration phase, the analysis of CN sensitivity shows its importance on direct flow simulation and for HEC-HMS results. Moreover, the optimal value for the study area is ranging between 30 and 40. In addition, the elaborated model is showing slightly sufficient performance when using TRMM precipitation data at a daily time scale even though its overestimations during intense precipitation events. As a conclusion, the model validation results show an instability estimation for simulated daily streamflow at the upper Oum Er Rbia basin.