Investigation of hydraulic regime at middle part of the Loire River in context of floods and low flow events

Significant variability characterizes natural streams in space and time that describe hydraulic regime of the entire stream. In this paper, the importance of investigation and assessment of hydraulic system in the context of management of surface water resources is discussed. The objective of this study is to investigate hydraulic regime in the middle part of Loire River located in France. Loire River basin is the largest river basin in France and origin of many potential flood events. Investigation of a hydraulic regime of the Loire River is conducted using traditional hydraulic simulation model HEC-RAS. Hydraulic modeling of the river is carried out by considering two different datasets (i.e. flood and low flow events). A certain number of hydraulic structures, which have the significant effect on the hydraulic regime of the river, is considered as well. Through Froude number computation, it is noticed that middle part of the Loire River demonstrates subcritical regime. Accurate calibration and validation of the model are performed by changing Manning coefficient along the riverbed. Computation carried out for both data sets; show that there are no big differences between observed and simulated water levels, results obtained are satisfactory. Therefore, to get more accurate information about the hydraulic regime at the middle part at of Loire River, the further simulation needs to be done by considering an additional dataset of floods and low flow events