A Parametric Flood Control Method for Dams with Gate-Controlled Spillways

Abstract

Abstract:The study presents a method which can be used to define real-time operation rules for gated spillways (named the K-Method). The K-Method is defined to improve the performance of the Volumetric Evaluation Method (VEM), by adapting it to the particular conditions of the basin, the reservoir, or the spillway. The VEM was proposed by the Spanish engineer Fernando Girón in 1988 and is largely used for the specification of dam management rules during floods in Spain. This method states that outflows are lower than or equal to antecedent inflows, outflows increase when inflows increase, and the higher the reservoir level, the higher the percentage of outflow increase. The K-Method was developed by modifying the VEM and by including a K parameter which affects the released flows. A Monte Carlo environment was developed to evaluate the method under a wide range of inflow conditions (100,000 hydrographs) and with return periods ranging from one to 10,000 years. The methodology was applied to the Talave reservoir, located in the South-East of Spain. The results show that K-values higher than one always reduce the maximum reservoir levels reached in the dam. For K-values ranging from one to ten, and for inflow hydrographs with return periods higher than 100 years, we found a decrease in the maximum levels and outflows, when compared to the VEM. Finally, by carrying out a dam risk analysis, a K-value of 5.25 reduced the expected annual damage by 8.4% compared to the VEM, which represents a lowering of 17.3% of the maximum possible reduction, determined by the application of an optimizer based on mixed integer linear programming (MILP method).

A Risk-Based Model for Real-Time Flood Control Operation of a Cascade Reservoir System under Emergency Conditions

“…The spillway reliability can be assessed through different methodologies as a fault tree analysis combined with an expert judgment [31,32]. Regarding to the flood control operation models and the assessment of the overtopping risk associated, stochastic parametric procedures [33,34] or probabilistic-multiobjective procedures [35,36] could have been accounted for. The proposed model is mainly used for the cascade reservoirs during flood season and its suitability in other situations could be evaluated.…”

A New Reservoir Operation Chart Drawing Method Based on Dynamic Programming

“…Here, for the simplified representation, only one increased output curve and one reduced output curve are provided. In Figure 1, the abscissa axis represents the time (month), and the ordinate axis represents the reservoir water level whose upper limit is the flood control level in the flood season the normal storage level in the non-flood season [35]. The curves in Figure 1 from top to bottom are in turn the increased output curve, the upper basic curve, the lower basic curve and the reduced output curve.…”

Influencia del nivel inicial en la definición de resguardos estacionales en presas

“…Carvajal et al, 2009;Gabriel-Martin et al, 2017) o la operación de los órganos de desagüe (p.e. Sordo-Ward et al, 2017). Se puede considerar que las leyes de frecuencia de niveles máximos en el embalse y de caudales máximos desaguados son las variables más representativas de la seguridad hidrológica tanto de la presa como aguas abajo de ésta (p.e.…”

“…Se puede considerar que las leyes de frecuencia de niveles máximos en el embalse y de caudales máximos desaguados son las variables más representativas de la seguridad hidrológica tanto de la presa como aguas abajo de ésta (p.e. Bianucci et al, 2013;Michailidi y Bacchi, 2017;Sordo-Ward et al, 2017), ya que incorporan de manera agregada todas las circunstancias que condicionan la seguridad.…”