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

Abstract

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.

A New Reservoir Operation Chart Drawing Method Based on Dynamic Programming

“…where H t is the average water head in the tth stage, unit: m; I t is the inflow rate in the tth stage, unit: m 3 /s; k is the efficiency coefficient; L t is the discarded water outflow rate in the tth stage, unit: m 3 /s; N t is the output in the tth stage, unit: kW; N t,min is the lower output limit in the tth stage, unit: kW; N t,max is the upper output limit in the tth stage, unit: kW; N t,exp is the expected output in the tth stage, unit: kW; q t is the outflow rate through the turbines of hydropower station in the tth stage, unit: m 3 /s; Q t is the whole outflow rate of reservoir in the tth stage, and Q t = q t + L t , unit: m 3 /s; Q t,min is the lower limit of Q t in the tth stage, unit: m 3 /s [38]; Q t,max is the upper limit of Q t in the tth stage, unit: m 3 /s; V t−1 is the volume of the reservoir at the beginning of the tth stage, unit: m 3 ; V t,min is the lower Energies 2018, 11, 3355 9 of 17 limit of V t in the tth stage, unit: m 3 ; V t,max is the upper limit of V t in the tth stage, unit: m 3 ; ∆t is the duration of an operation stage, which is 2,628,000 s in this paper. After the reservoir operation chart is obtained, it can be used to guide the actual reservoir operation, that is, the operation decision can be made according to the reservoir's current water level and the operation zone where the water level located in the chart.…”

UAVs for Hydrologic Scopes: Application of a Low-Cost UAV to Estimate Surface Water Velocity by Using Three Different Image-Based Methods

“…There are various tools and methods to measure the stream velocity and discharge from rating curves to acoustic Doppler devices [15,16] and modeling tools [17]. During the last decades, The river flow is generated by water inputs of an extensive underground karst system, and flows as an underground river at Aggitis (or Maara) Cave [45].…”

Simulation-Based Exceedance Probability Curves to Assess the Economic Impact of Storm Surge Inundations due to Climate Change: A Case Study in Ise Bay, Japan

“…Risk is a function of hazard, exposure, and vulnerability [5]. However, for natural disasters, many studies have focused on only hazard prediction [6][7][8] and have followed a hazard-projection-hazard-countermeasure decision process [9]. The concept of risk in natural disasters emphasizes the integration of hazard, exposure, and vulnerability, and promotes the decision process of hazard-projection-social impact evaluation-risk-estimation-risk-countermeasures.…”