Subjects: Hydraulic Engineering >> Other Disciplines of Hydraulic Engineering submitted time 2024-04-01
Abstract： A new digital twin (DT) framework with optimal sensor placement (OSP) is proposed to accurately calculate the modal responses and identify the damage ratios of the offshore jacket platforms. The proposed damage identification framework consists of two models (namely one OSP model and one damage identification model). The OSP model adopts the multi-objective Lichtenberg algorithm (MOLA) to perform the sensor number/location optimization to make a good balance between the sensor cost and the modal calculation accuracy. In the damage identification model, the Markov Chain Monte Carlo (MCMC)-Bayesian method is developed to calculate the structural damage ratios based on the modal information obtained from the sensory measurements, where the uncertainties of the structural parameters are quantified. The proposed method is validated using an offshore jacket platform, and the analysis results demonstrate efficient identification of the structural damage location and severity.
Subjects: Mathematics >> Mathematics （General） Subjects: Hydraulic Engineering >> Basic Disciplines of Hydraulic Engineering submitted time 2023-04-28
Abstract： In this paper, we mainly provide a proper maintenance plan for the Kariba Dam in Africa which falls into disrepair and is facing to collapse. Firstly, we make a threshold analysis of the three options about their costs which include people’s moving, old dam’s removing, new dams’ building, later repairing, ecological destruction and their incomes which include generation energy, avoiding of flood disasters’ loss, providing employment, tourism resources and ecological protection. Then we get the specific relationship between benefits and years with some collected data. Both of the results show that the third option is the best choice from the economic view. And the result is completely as same as the conclusion we get after studying deeply on Option 3. Secondly, we regard water management capabilities as the safety coefficient of dams. We select 30 seed points along the riverbank for preparing the establishment of dams. With flow-between-riverway model, Manning equations, large Cauchy distribute function we get the scores of the seed points. We give an advice that the number of dams should be more and the positions of dams should be well-distributed. Then, we build an assessment model by analytic hierarchy process. We select three factors among all the factors, safety, economy and population. After testing the consistency, we get the weights of each factor: 0.6442, 0.2705, 0.0852. Then we value the factors and get an optimal scheme during the assessment with 0-1 integer programming: the number of dams is 17 and the longitude and latitude of them are shown in Table 17. The sensitivity of the result is tested as well. We also provide some strategies for the managers of ZRA to use. We suggest that they should use the dams normally in general. With the Dam-break model, we find 13 points among 17 points which are shown in Table 20. The dams at the 13 points need to be closed when there is a flood and it is just the opposite when the drought happens. For the extreme water flow, we assume an ideal water flow at first. The extreme water flow has to be adjusted to satisfy the ideal one. As for the restrictions in extreme conditions, the biggest impact happens at the 8th point among the 17 points. If the duration of maximum flow is t0, the drainage time t to make the water flow return to the normal level equals to 4.95t0.
Peer Review Status:
Awaiting Review
Subjects: Hydraulic Engineering >> Hydraulic Management submitted time 2021-09-01
Abstract： "
Peer Review Status:Awaiting Review
Subjects: Hydraulic Engineering >> Flood Control submitted time 2021-09-01
Abstract： "
Peer Review Status:Awaiting Review
Subjects: Hydraulic Engineering >> Hydraulic Management submitted time 2021-09-01
Abstract： "
Peer Review Status:Awaiting Review
Subjects: Hydraulic Engineering >> River Silt Engineering submitted time 2021-09-01
Abstract： "
Peer Review Status:Awaiting Review
Subjects: Hydraulic Engineering >> Environmental Water Conservancy submitted time 2021-09-01
Abstract： Water is the lifeblood of Yellow River, and the eco-environmental health of rivers and lakes is one of the core elements for ecological protection and high-quality development of Yellow River Basin. How to realize comprehensively eco-environmental recovery of rivers and lakes in Yellow River Basin is the hot issue in current. The entropy model based on the proposed Environment Development Index is employed, in this paper, to evaluate the evolution characteristics of rivers and lakes eco-environment in Yellow River Basin and to analyze the existing problems. Then, the goal and pattern for the eco-environmental recovery of rivers and lakes in Yellow River Basin are discussed and the corresponding ideas are put forward. The results show that (1) the eco-environmental system of Yellow River Basin is changing from disordered development to orderly development; (2) Measures such as unified operation of the main Yellow River, soil and water conservation can promote the eco-environmental recovery of rivers and lakes in Yellow River Basin; (3) It is necessary to coordinate the upstream and downstream areas, the left and right banks, and the water and land areas, with the goal of ecological protection and treatment, groundwater over-extraction and comprehensive control of soil and water loss, so as to continuously promote the eco-environmental full recovery of rivers and lakes in Yellow River Basin. "
Peer Review Status:Awaiting Review
Subjects: Hydraulic Engineering >> Basic Disciplines of Hydraulic Engineering submitted time 2021-02-22
Abstract： Quality and stability are the basic characteristics of the ecosystem, which comprehensively reflect the structure, process, and functional integrity of the ecosystem and the ability to resist interference, self-regulation, and dynamic balance. The Yellow River Basin is a complex giant system composed of many elements. The management and protection of the river basin ecosystem has received more and more attention. It is necessary to start from the integrity of the ecosystem, make overall considerations, and implement comprehensive policies to improve the quality and stability of the ecosystem, and promote a virtuous cycle of the ecosystem, so the quantitative description of system quality and stability is very important. This paper uses the entropy weight model to establish a multi-index long-term series of Ecosystem Quality Index (EQI) to quantitatively describe the changes in ecological quality in the Yellow River Basin in the past 40 years; at the same time, use the dissipative structure theory and the Brussels model to establish the steady-state transformation of the ecosystem Quantitative indicators and methods provide ideas for the study of steady-state transformation of the Yellow River Basin ecosystem. The study found that: (1) The average EQI value of the Yellow River Basin ecosystem over the past 40 years is 0.64, the maximum value is 0.70, and the minimum value is 0.59. The overall quality is showing an oscillating trend for improvement; (2) The steady-state conversion power value of the system is less than 0, indicating that the steady-state conversion power of the ecological-human-society coupling system in the Yellow River Basin is low, but the overall trend is oscillating upward, and the overall trend is getting closer and closer to the critical conditions for achieving steady-state conversion.
Peer Review Status:Awaiting Review
Subjects: Hydraulic Engineering >> Basic Disciplines of Hydraulic Engineering submitted time 2021-02-19
Abstract： The Yellow River Basin is a complex giant system with numerous elements and complex relationships, which are both interrelated and mutually restrictive. Since the people's control of the Yellow River, watershed governance and protection have achieved remarkable results, but there are still some outstanding problems, which fully embodies the "appearance in the Yellow River, roots in the basin", and reveals the complexity, coordination and integrity of watershed governance and protection work. The high-quality development of the river basin needs to break the traditional "headache and foot pain" river basin governance model, and carry out more in-depth research from the perspective of comprehensive governance, system governance, and source governance. In particular, it is urgent to study the comprehensive evaluation theory of watershed development quality. Based on basic theories such as system science and information theory, this research puts forward a comprehensive evaluation theory of watershed development quality, constructs a basin development index (BDI) and a three-tier evaluation system of macro-medium-micro level, and explores the evolution law of the watershed giant system, Provide technical support and theoretical basis for river basin governance and protection."
Peer Review Status:Awaiting Review
Subjects: Hydraulic Engineering >> Basic Disciplines of Hydraulic Engineering submitted time 2021-01-30
Abstract： From the perspective of systematic thinking, this study applied the theories of information entropy and dissipative structure to comprehensively evaluate and analyze the evolution of the complex system of the Yellow River Basin over the past 40 years. With the concept of “Basin Development Index (BDI shortly)”, a preliminary scientific comprehensive evaluation method system of basin development quality is established. Results of the model calculation show that the ratio of per capita GDP in the basin to the national average and the total sedimentation in the lower Yellow River have occupied the largest weight for many years, and have had a relatively greater impact on the development of the basin in different historical periods. During the entire 40 years, the value of BDI has varied from 50.5 points in 1996 to 66.6 points in 2019, and has generally experienced a decreasing and an increasing stage. The evolution of BDI of Yellow River basin is consistent with the overall law of the basin development and has a great correlation with some major events happened in the basin. In addition, this research method can be extended to other fields such as regional governance. Compared with the current evaluation models mainly based on economic indicators, this novel methodology is more systematic and scientific, and will better serve the decision-making with more scientific thoughts.
Peer Review Status:Awaiting Review
Subjects: Hydraulic Engineering >> River Silt Engineering submitted time 2021-01-29
Abstract： This article systematically summarized the development process of the operation mode of reservoirs on sediment-laden rivers in China since the 1950s, especially explained the application and design technology of "storing clean water and regulating muddy flow". The so-called " storing clean water and regulating muddy flow " application is to fully consider the changes in the incoming water and sediment process in the reservoir according to the requirements of the reservoir development task, and coordinate the impact of the sediment on the siltation form and effective reservoir capacity to maximize the coordination degree of the water-sediment relationship in the downstream river as the core. Through the comprehensive coordinated control of "blocking, regulating and discharging", the comprehensive utilization benefits of reservoirs can be brought. In design, in order to better exert the reservoir regulation function, it is necessary to consider the demand for storage capacity of water and sediment regulation, and set up sufficient water and sediment regulation storage capacity to reduce the adverse impact of the forced sediment discharge of the reservoir on the downstream water-sediment relationship. The storage capacity distribution design is based on the rules of “deep channel for sediment regulation, medium channel for benefit and high channel for flood regulation”, to avoid the use of effective reservoir capacity due to sedimentation. Rivers with ultra-high sediment content should set abnormal sediment discharge bottom outlets to form a "normal + abnormal" double sediment erosion datum plane, to realize the recycling of part of the sediment storage capacity, and the integrated utilization of sediment storage capacity and water and sediment regulation storage capacity. Reservoir should adopt water and sediment separation development method, which is “"mainstream large reservoirs for sediment regulation, tributary small reservoirs for water supply", in rivers with super high sediment content to solve the contradiction between effective reservoir capacity maintenance and water supply regulation. On the basis of achieving long-term preservation of effective storage capacity, "storing clean water and regulating muddy flow" better takes into account the needs of reservoir water and sediment regulation in sediment-laden rivers. The results will provide guidance and reference for the reservoir engineering design and operation of sediment-laden river, in the current and future periods.
Peer Review Status:Awaiting Review
Subjects: Hydraulic Engineering >> Basic Disciplines of Hydraulic Engineering submitted time 2021-01-26
Abstract： Ecological conservation and high-quality development of the Yellow River Basin has become a major national strategy. The socio-economic development of the Yellow River Basin is one of the main factors affecting the governance and protection of the Yellow River. It has become a scientific issue to analyze the law of socio-economic development of the Yellow River Basin and give countermeasures. . This paper selects 12 socio-economic characteristic indicators from four perspectives: population characteristics, residents’ quality of life, economic growth level, and regional industrial structure. The social development index (SDI) is calculated by the entropy method, and the Yellow River Basin is quantitatively analyzed in the past 40 years. The research shows that the social development index of the Yellow River Basin in the past 40 years shows a trend of "down stable up", especially after 2012, with the gradual maturity of economic transformation, the social development of the Yellow River Basin is on the whole better. "
Peer Review Status:Awaiting Review
Subjects: Hydraulic Engineering >> Basic Disciplines of Hydraulic Engineering submitted time 2021-01-26
Abstract： The Yellow River is the mother river of Chinese nation. In recent years, the inflow and sediment of the Yellow River have decreased, with extreme climate events occurred frequently, the boundary conditions have changed greatly. As the rapid economic and social development, it is necessary to carry out river health diagnosis under the changing environment. This research adopted information entropy and entropy weight methods to study the evolution characteristics of the healthy development of the Yellow River basin. Results showed that: (1) The river system presented healthy in 1980~1986, unhealthy in 1987~1999 and sub-healthy in 2000~2019. (2) The river system showed a healthier trend within 1980~1984, an increasingly unhealthy trend in 1984~1996, while following a good development trend in 1996~2019. (3) The flood discharge capacity of the main channel of the Ningxia-Inner Mongolia reach and the total amount of erosion and deposition in the downstream are the most sensitive factors.
Peer Review Status:Awaiting Review
Subjects: Hydraulic Engineering >> Basic Disciplines of Hydraulic Engineering submitted time 2021-01-25
Abstract： The ecological environment of the Yellow River Basin is systematic and complicated. It is of great significance to study the quantitative evaluation and change characteristics of the Yellow River Basin by providing scientific basis on integrated river basin management. This in one of the current widespread concerns and urgent problems to be solved. Through calculating the entropy weights of eco-environmental indicators in Yellow River Basin from 1980 to 2019, the dynamic entropy weight results were verified. Then the importance of the individual indicator in system was proved to be variable. On this basis, the EDIs (Environment Development Indexes) of the Yellow River Basin from 1980 to 2019 were analyzed and plotted by curve, which valued between 56.64～76.60. The changing trend of EDI in the Yellow River Basin was almost presented stabilized before 2003, and continuously increasing from 2003. The results show that through the years of protection and restoration, the ecological negative feedback was exerted profound effect, resulting the ecological environment of the Yellow River Basin was changing well.
Peer Review Status:Awaiting Review
Hits
YES
Hits
Downloads
Comment