Risk assessment of multireservoir joint flood control system under multiple uncertainties

Self Cite

In practical applications, the rational operation rule derivation can lead to significant improvements in the middle and long-term joint operation of cascade hydropower stations. The key issue of actual optimal operation is to select effective attributions from the deterministic optimal operation results, however, there is still no general and mature method to solve this problem. Firstly, the joint optimal operation model of hydropower reservoirs considering backwater effects are established. Then, the dynamic programming and progressive optimality algorithm are applied to solve the joint optimal operation model and the deterministic optimization results are obtained. Finally, the grey relational analysis method is applied to select more effective factors from the obtained results as the input of a support vector machine for further operation rule derivation. The Xi Luo-du and Xiang Jia-ba cascade reservoirs in the upper Yangtze river of China are selected as a case study. The results show that the proposed method can obtain better input factors to improve the performance of SVM, and smallest value of root mean square error by the proposed method of Xi Luo-du and Xiang Jia-ba are 94.33 and 21.32, respectively. The absolute error of hydropower generation for Xi Luo-du and Xiang Jia-ba are 2.57 and 0.42, respectively. Generally, this study provides a well and promising alternative tool to guide the joint operation of hydropower reservoir systems.

Section: Case Studymentioning

confidence: 98%

Operation Rule Derivation of Hydropower Reservoirs by Support Vector Machine Based on Grey Relational Analysis

Zhu

Zhou

Qiu

et al. 2021

Self Cite

“…However, the obstacles to the safety of RFCO problems are not only related to the complexity of extracting the optimal rules for RFCO operational stages but also the associated uncertainties of RFCO variables (e.g., flood peak flow) and, subsequently, the RFCO targets. Therefore, several studies considered the uncertainties in RFCO and estimated their corresponding risks to support the decision-makers in developing effective dam operational plans under various conditions [161,[167][168][169][170][171][172][173][174][175][176][177]. These uncertainties are introduced from four main sources [178][179][180]: (1) hydrological (e.g., inflow) and meteorological variables (e.g., precipitation) uncertainties that introduce randomness in flood frequency and its magnitude; (2) flood forecasting and river flood routing errors, as a result of models structure uncertainty, parameter estimation errors, imperfection of initial and boundary conditions, and simplification of the physical processes; (3) hydraulic uncertainties, such as errors in reservoir outflows (e.g., due to debris accumulations), and errors in reservoir discharge curve (i.e., the difference between actual and designed spillway capacity resulted from flow coefficients and measurement errors of the spillways); and (4) other uncertainties (i.e., deep uncertainties), such as operation time delay, human decision errors, information unavailability, poor communication.…”

Section: Topic 3: Flood Riskmentioning

confidence: 99%

Dam System and Reservoir Operational Safety: A Meta-Research

Badr,

Li,

El-Dakhakhni

2023

Dams are critical infrastructure necessary for water security, agriculture, flood risk management, river navigation, and clean energy generation. However, these multiple, and often conflicting, objectives introduce complexity in managing dam operations. In addition, dam infrastructure has been evolving as complex systems-of-systems with multiple interacting components and subsystems, all susceptible to a wide range of uncertainties. Such complexities and uncertainties have triggered extensive research initiatives focused on dam systems and reservoir operational safety. Focusing on the latter, this paper meta-researches (conducts research-on-research) previously published studies to identify the critical research gaps and propose future research directions. In this respect, this paper first performs a quantitative analysis of the pertinent literature, using text mining and subsequent topic modeling, to identify and classify major and uncover latent topics in the field. Subsequently, qualitative analysis is conducted to critically review the identified topics, exploring the concepts, definitions, modeling tools, and major research trends. Specifically, the study identified seven topics: optimization models; climate change; flood risk; inflow forecasting; hydropower generation; water supply management; and risk-based assessment and management. The study also presents three main research gaps associated with the limitations in modeling concepts, modeling tools capabilities, and the lack of resilience-guided management of dam operational safety. Overall, this study presents a road map of the currently available dam and reservoir operational safety research and associated knowledge gaps, as well as potential future research directions to ensure the resilience of such critically important infrastructure, especially in the age of climate change.

“…While design floods and historical floods provide some insight, they are not sufficient. Therefore, it is necessary to simulate reservoir inflows [22]. Disaggregation methods break down runoff from larger time scales into smaller ones based on historical runoff, which effectively captures the statistical characteristics of both large-and small-scale runoff [23].…”

Section: The Uncertainty Of Reservoir Inflowsmentioning

confidence: 99%

Research on Flood Risk Control Methods and Reservoir Flood Control Operation Oriented towards Floodwater Utilization

Zhou,

Kang,

Hou

et al. 2023

Since improving floodwater utilization may increase flood risk, flood risk control methods for trade-offs between these factors have research value. This study presented a flood risk control method oriented towards floodwater utilization which considers multiple main flood risk factors. The proposed method not only achieves the boundaries of the flood limited water level (FLWL) under various acceptable risks but also dynamically controls the water level to enhance floodwater utilization. A case study conducted on the Danjiangkou reservoir yielded the following results: (1) The proposed method provides FLWL dynamic control boundaries under various acceptable risks. (2) The proposed method reveals the potential to raise the FLWL, with a possibility to raise it by 1.00 m above the present FLWL under the absence of flood risk. (3) The available flood resources in both the wet and dry seasons increase, on average, by 0.83 and 0.81 billion m3, and the flood risk remains within the acceptable range after raising the FLWL by 1.00 m, which contributes to enhancing floodwater utilization.