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The risk of flood or waterlogging in irrigation districts has increased due to global climate change and intensive human activities. A Model of Optimal Operation of Drainage Works (MOODW) for flat irrigation district was established by incorporating the hydrological model of waterlogging process and waterlogging loss estimation, which was solved by an optimization method of genetic algorithm. The model of waterlogging process was built based on a modified Tank model and hydrodynamic model for the ditch-river system. The waterlogging loss is calculated under the condition of inconstant inundated depth by linear interpolation. The adaptive genetic algorithm with the global optimization function was selected to solve the model. With an extreme rainfall events in Gaoyou irrigation district as cases, results showed that operation time and numbers of pumps increased, thus, operating costs were 1.4 times higher than before, but the yield loss of rice decreased by 35.4% observably. Finally, the total waterlogging loss was reduced by 33.8% compared with the traditional operation of waterlogging work. The most significant improvement was found in units with high waterlogging vulnerability. The MOODW can provide the waterlogging information visually and assist the district manager in making a reasonable decision.

A pilot-scale multilevel contact oxidation reactors system, coupled with saran lock carriers, was applied for the treatment of poultry farm wastewater. The removal efficiencies of CODcr, ammonia, and the total nitrogen as well as the elimination performance of CODcr and total nitrogen along the three-level contact oxidation tanks under six designed operational models were investigated. Based on the performance of the nitrogen removal of the saran lock carriers and the distribution of anoxic–aerobic interspace under the suitable operation model, the mechanism of nitrogen removal of the system was also explored. The results revealed that the intermittent aeration under parallel model is the most suitable operation model, while the removal efficiencies of CODcr, ammonia, and the total nitrogen were 86.86%, 84.04%, and 80.96%, respectively. The effluent concentration of CODcr, ammonia, and the total nitrogen were 55.6 mg/L, 8.3 mg/L, and 12.0 mg/L, which satisfy both the discharge standard of pollutants for livestock and poultry breeding industry (GB 18596–2001) and the first grade of the integrated wastewater discharge standard (GB 8978–1996). Moreover, the mechanism for the nitrogen removal should be attributed to the plenty of anoxic–aerobic interspaces of the biofilm and the three-dimensional spiral structure of the saran lock carriers, where the oxygen-deficient distribution was suitable for the happening of the simultaneous nitrification and denitrification process. Therefore, the multilevel contact oxidation tanks system is an effective pathway for the treatment of the poultry farm wastewater on the strength of a suitable operation model and novel carriers.

Simulation models of river reservoir functioning in which dynamic volume nomograms are used to consider the non-horizontal nature of the reservoir water surface have not been so far applied due to the lack of accurate and fast-working computer realizations of such models. In 2015–2016, the authors of this paper developed such a program. In the periods of carrying out special-purpose spring water releases to the lower reaches of the Volga River in 2016 and in 2017, the developed model was used in a trial mode for a designing the reservoirs’ water regime. The results of water releases carried out under complicated hydrological and economic conditions proved the high performance of the model and confirmed the prospects of its application to solve the inverse problem.

To make full use of inflow forecasts with different lead times, a new reservoir operation model that considers the long-, medium- and short-term inflow forecasts (LMS-BSDP) for the real-time operation of hydropower stations is presented in this paper. First, a hybrid model, including a multiple linear regression model and the Xinanjiang model, is developed to obtain the 10-day inflow forecasts, and ANN models with the circulation indexes as inputs are developed to obtain the seasonal inflow forecasts. Then, the 10-day inflow forecast is divided into two segments, the first 5 days and the second 5 days, and the seasonal inflow forecast is deemed as the long-term forecast. Next, the three inflow forecasts are coupled using the Bayesian theory to develop LMS-BSDP model and the operation policies are obtained. Finally, the decision processes for the first 5 days and the entire 10 days are made according to their operation policies and the three inflow forecasts, respectively. The newly developed model is tested with the Huanren hydropower station located in China and compared with three other stochastic dynamic programming models. The simulation results demonstrate that LMS-BSDP performs best with higher power generation due to its employment of the long-term runoff forecast. The novelties of the present study lies in that it develops a new reservoir operation model that can use the long-, medium- and short-term inflow forecasts, which is a further study about the combined use of the inflow forecasts with different lead times based on the existed achievements.

Hydropower plays an extremely important role in the energy market with the increasing energy demand. The intra-annual runoff distribution (IARD) in the hydrological year has an important impact on the energy generation of cascade hydropower plants (CHP). This study evaluated the non-uniformity of IARD of the Datong River basin (DRB) in the hydrological year. The optimal operation model of CHP was constructed based on the genetic algorithm to investigate the impact of the non-uniformity of IARD on the energy generation of CHP. This study shows the following: 1) The observed runoff series has a decreasing trend, the non-uniformity of IARD has an increasing trend overall. 2) The energy generation of CHP shows a weak decreasing trend affected by the decrease of runoff and the increase of non-uniformity. 3) With or without water diversion, the CHP energy generation decreases with the increase of non-uniformity of IARD. 4) The difference of energy generation of CHP between consideration or not the water diversion is about 400 GWh when the inflow frequency is less than 50%. 5) The impact of non-uniformity of IARD on energy generation will be greater with the inflow increasing. This study can provide theoretical support for the water resources management and operation of CHP.

The TES (thermal energy storage) tank has been widely used in CHP (combined heat and power) units to consume more renewable energy. In this paper, the hourly operation model has been established to solve the operation strategy problem of TES tank. The limitations of standard genetic algorithm used in the operation strategy of TES tank have been analyzed, then an improved genetic algorithm is proposed. At last, the improved genetic algorithm is used to optimize the operation strategy of TES tank by combining the characteristic day method. The results show that the improved genetic algorithm can enhance the local search ability and calculation speed obviously, and the calculation speed will be further improved after combining the characteristic day method. In order to obtain the maximum profit, the TES tank should store thermal energy at high minimum power load and release thermal energy at low minimum power load. In addition, the optimal capacity of TES tank in different months varies greatly during the period of thermal energy supply. The optimal capacity of TES tank should be the maximum value among all the months to ensure the thermal energy supply.

Flexible Load (FL) of electricity, heat and gas can improve the operation economy, flexibility and reliability of PIES. Aiming at the uncertainty of FL in the actual operation of the park integrated energy system (PIES), an optimal operation model of PIES with uncertainty of FL is proposed. Firstly, the uncertainty models of shiftable electric load and transferable load response are established, respectively. And then an adjustable heat load response model considering the uncertainty of solar radiation intensity is established. On this basis, an optimal operation model of PIES considering the uncertainty of the FL with the goal of maximizing the total revenue is constructed and is solved by the enhanced-interval linear programming method. Simulation indicate that FL can improve the operating economy of PIES and renewable energy consumption.

Red oak (Quercus rubra L.) is our most important exotic oak species, that possesses growing culture with almost one hundred years in our country. Plantation character of red oak growing predominates principally by applied regeneration method (mostly artificial), regular planting space, applying defined method and planting space regulation system. Forest tending model for red oak, that considered stopgap in the native literature is intended to serving the latter. Especially important equation in the viewpoint of stand growing, that describes relationship of stem number (N, in hectare) and diameter at breast height (D1.3 in cm) is: N=e9.80220-1.12607lnD1.3.

Before natural gas is supplied to the main gas pipeline, gas is cleaned and dried. Natural gas treatment is one of the main processing steps during production and preparation in the field conditions. The paper considers the separation equipment model development in the form of the Cobb-Douglas production function to define the main performance parameters.

The thermal inertia of district heating system (DHS) has been considered in the combined heat and power (CHP) system operation to reduce wind curtailments. While DHS usually operates at the quality-regulation mode, under which the potential of public buildings to regulate heat demand is not fully exploited. In this paper, according to the different heat demand characteristics of public buildings (PB) and residential buildings (RB), a CHP system operation model adopting a centralized control with flow varied by steps in DHS operation regulation is proposed. Case studies show that the proposed model has better performance in economic benefits and wind power integration.

Wind energy is a renewable and energy-rich clean energy source, which is of great significance for energy conservation and emission reduction. However, the uncertainty of wind power makes the wind aggravation. This paper focuses on the principle of cooperative operation mechanism of regenerative electric heating and wind power generation and constructs a cooperative operation model considering relevant constraints. The economics of the model are evaluated by establishing an economic evaluation system. Finally, case studies show that the coordinated operation of wind energy and regenerative electric heating improves the wind power's ability to absorb and the system's peaking ability, effectively alleviating the wind abandonment phenomenon. At the same time, it has improved economics and improved the environment. Contributed to China's resource conservation and environmental protection.

The Yaqui River Basin (YRB) is in the semiarid state of Sonora in northwest Mexico. The flow in this watershed is controlled by three reservoirs: Angostura, Novillo, and Oviachic. A daily r...

To alleviate the negative impacts on ecosystem caused by cascaded development of Yuan River, this study quantified the ecological requirements and incorporated them into the cascaded reservoir operating schemes to provide the streamflow that balances fish habitat protection and hydropower generation. Physical habitat simulation model is proposed to simulate the relationship between streamflow and physical habitat for various life stages of Cyprinus rubrofuscus Lacepede and Bagarius rutilus Ng & Kottelat , and to determine the ecological requirement as a discharge range associated with the upper area of a certain proportion of maximum Weighted Usable Areas ( WUA ). Then the optimal operation model of cascaded reservoirs is established. Maintaining over 70% of maximum WUA as an example, the optimization technique could increase the hydropower generation of cascaded reservoirs by 3.60%, 1.93% and 4.19%, and also improve the ecological conditions by increasing the WUA s by 11.3%, 17.9% and 16.2% for Section A and 7.4%, 12.4% and 14.4% for Section B under wet, normal and dry conditions, respectively. Furthermore, the trade-offs between hydropower production and fish habitat conservation are discussed. The optimal compromises were identified at the knick points in the established relations where 50%–70% of maximum WUA are conserved at a cost of 11.72–52.11 billion kW h (1.8%–8.4%) power generation loss.

In order to apply the emergency operation Model in Upstream Pools of the Accident Pool of the Middle Route of South-to-North Water Diversion Project we have developed, a one dimensional hydraulic model was developed and a case study was carried out. The results showed the emergency operation model can determine reasonable emergency operation measures in the upstream pools. In addition, some suggestions were put forward to help deal with the emergency operation measures in the upstream pools.

The objective of this study was to establish a method to calibrate a large-scale laboratory rainfall simulator through developing and implementing an automated rainfall collection system to assess the reliability and accuracy of a rainfall simulator. The automated rainfall collection system was designed to overcome the limitations caused by the traditional manual measurement for obtaining the rainfall intensity and the spatial rainfall distribution in a large experimental area. The developed automated rainfall collection system was implemented to calibrate a large-scale laboratory rainfall simulator. The adequacy of average rainfall intensities automatically collected from the miniature tipping bucket rain gauges was assessed by comparison with those based on the volumetric method using the flowmeter. The functional relationships between the system variables of the rainfall simulator and the simulated intensity and uniformity distribution of rainfall (i.e., operation models) were derived based on a multiple regression approach incorporating correlation analysis on linear and logarithm scales, with consideration of a significance level. The operation models exhibited high accuracy with respect to both the rainfall intensity and the uniformity coefficients.

The demand response and battery energy storage system (BESS) will play a key role in the future of low carbon networks, coupled with new developments of battery technology driven mainly by the integration of renewable energy sources. However, studies that investigate the impacts of BESS and its demand response on the adequacy of a power supply are lacking. Thus, a need exists to address this important gap. Hence, this paper investigates the adequacy of a generating system that is highly integrated with wind power in meeting load demand. In adequacy studies, the impacts of demand response and battery energy storage system are considered. The demand response program is applied using the peak clipping and valley filling techniques at various percentages of the peak load. Three practical strategies of the BESS operation model are described in this paper, and all their impacts on the adequacy of the generating system are evaluated. The reliability impacts of various wind penetration levels on the generating system are also explored. Finally, different charging and discharging rates and capacities of the BESS are considered when evaluating their impacts on the adequacy of the generating system.

How to make operation strategy for regional multi-energy system with less energy loss and small cost is worth studying. Optimal operation model of regional multi-energy system is built based on heating water network model, considering heating loss of hot water pipes caused by temperature drop and power consumption of circulating water pump caused by water flow. The corresponding algorithm is introduced to achieve the solution of the model built in this paper. Finally, a supposed multi-energy system is used to conduct a simulation, and the results show that the proposed optimization model of making operation strategy for regional multi-energy system can further reduce energy loss and operation cost.

Pyroprocessing is a complicated batch-type operation, involving a highly complex material flow logic with a huge number of unit processes. Discrete event system modeling was used to create an integrated operation model for which simulation showed that dynamic material flow could be accomplished to provide considerable insight into the process operation. In the model simulation, the amount of material transported upstream and downstream in the process satisfies a mass balance equation while considering the hold-up incurred by every batch operation. This study also simulated, in detail, an oxide reduction group process embracing electrolytic reduction, cathode processing, and salt purification. Based on the default operation scenario, it showed that complex material flows could be precisely simulated in terms of the mass balance. Specifically, the amount of high-heat elements remaining in the molten salt bath is analyzed to evaluate the operation scenario.

The existence of dams cannot be ignored. The dam-lake formed due to the construction of a dam can be considered an integrated part of the natural watershed. A question which must be answered is how to operate a dam-lake so that the negative impacts of the dam on the natural flow system are reduced and at the same time the intended purposes of the dam are efficiently met. Among many aquatic species, the fish species are probably the most highly impacted species by the construction of a dam. As a result of the dam, fish habitat can decrease resulting in low productivity to no productivity at all for some fish species. This paper presents a methodology to develop a dam-lake operation model to maximize fish habitat. This study considered the physical habitat of smallmouth bass in its adult life. The operation model is developed by linking one-dimensional hydraulics model HEC-2 and dam-lake simulation model HEC-5 with a meta-heuristic optimization algorithm, the Shuffled Frog Leaping Algorithm (SFLA). The computation of physical habitat, which is a function of habitat suitability index and some hydraulic parameters, is coded within the optimization algorithm. The model has been successfully applied to an unnamed dam-lake in the northeast of the U.S. The fish habitat for smallmouth bass in its adult life stage increases as the water surface in the dam-lake increases. Some recommendations to improve the model are discussed in the conclusions section.

Many estuaries present natural harbor conditions with relatively calm and shallow waters that provide a connection between the ocean and continental waterways. The increase in the demand for goods by the constant growing of the world population has forced estuaries to be altered by human activities, such as dredging, in order to maintain a safe navigation system. The development of sophisticated morphological and hydrodynamic models opened a new perspective of assisting dredging operations inside different estuaries. Thus, the aim of this study is to apply a hydromorphodynamic model to simulate the bed evolution of the Patos Lagoon estuary, southern Brazil. The results of the simulation were applied in a dredge operation model to simulate dredging inside the waterway of the Rio Grande harbor, located inside the Patos Lagoon estuary. The salinity and current velocities inside the estuary were well represented by the model simulations. An annual mean discharge of 3 407 ms3 s−1 was calculated for the lagoon for the year 2004. The morphodynamic model successfully represented the silted and eroded scenarios for the estuarine channel. The dredge operation model results affirm that dredging of the channel causes significant variations in estuarine physical parameters such as salinity, current velocity and suspended sediment concentration. The bed evolution results indicate that a fast siltation of the channel occurs right after dredging stops, stabilizing the variations after a 60-day period.

Based on the characteristics of weather modification in Yunnan Province, this paper proposed a weather modification operation model which aims to help operating managers with operating scenario and provide operating spots, fixed or mobile, with detailed intelligent decision-making information, including: operating spot, fire elevation, azimuth, amount of ammunition. The data that this model utilizes is from the conventional sounding materials, XDR radar and DPL radar together with the historical applications and actual usage.

Typhoon events occur frequently in Taiwan resulting in flood-related disasters. A well-operated reservoir can reduce the severity of a disaster. This study incorporates a genetic algorithm, a river hydraulic model, an artificial neural network and a simulation model of Tseng-Wen Reservoir to propose a real-time flooding operation model. The model includes two parts: an optimal flooding operation model (OFOM) and a reservoir inflow forecasting. Given an inflow condition, the OFOM is run based on the safety of the dam structure, reservoir flooding operation rule, and minimization of the downstream loss due to flood. A simple and robust model for reservoir inflow forecasting, which automatically chooses the most similar event from a typhoon event database as the future inflow, is developed. This study compares the model results with the real operations during Typhoons Sepat, Krosa, Kalmaegi, Fung-wong, Sinlaku, and Jangmi. This study compares the performances of the proposed model with the practical operation operated by the management center of Tseng-Wen Reservoir. The proposed model indicates shorter flooding duration in the downstream area. For example, the flood durations of the model output are 4 and 3 hours shorter during Typhoon Krosa and Sinlaku, respectively, than the practical operations.

The study develops a rule operation model for gated spillways which improves the performance of the volumetric evaluation method (MEV). MEV was proposed by Giron (1988) and is largely used in common practice in Spain. The improvement was made by applying a corrective factor to the outflow discharge proposed by MEV method. The choice of the corrective factor was based on a multi-decision environment accounting for the number of improved cases and the amount of improvement. A Monte Carlo simulation environment was created to evaluate the method under a wide range of operating conditions. The environment includes the generation of storms and inflow hydrographs and their routing through the reservoir. The methodology was applied to the Talave basin, in the south-east of Spain. The improved method (called K method) was compared with other methods for the operation of gate-controlled spillways as the MEV and PLEM methods. The results showed that if the corrective factor K is higher than 1 the number of improved cases was significant, while if it is lower than 1 there was not improvement. The analysis of the relation between the return period and the devised method showed that by using the K method the percentage of improvement of both reducing maximum outflows and reducing maximum levels reached in the reservoir is greater for events with higher return periods than for the lower ones.

Serving one of the largest metropolitan areas in the United States, the George Bush Intercontinental Airport (IAH) in Houston, Texas, is one of the 10 airports with the longest average taxi-out and taxi-in times. This paper assesses the congestion at IAH by analyzing taxi times and flight data during different hours of the day. The capacity of IAH is investigated by examining the number of departing flights on the ground. IAH is operating close to capacity most of the time. Because increasing airport capacity can mitigate congestion, this report develops a surface operation model based on analyzed results to achieve this aim. A mixed-integer programming formulation is proposed to optimize total taxi times by finding optimal taxi routes and the related schedules. The model is applied to a sample from real data.

The technology of multi-energy supply and energy storage can both improve the efficiency of energy use and the renewable energy absorption capacity of system, in which way they have wide application prospects. Based on the actual data of a park in East China, an integrated energy microgrid containing CCHP system and energy storage was modelled, in which the nonlinear characteristics of each equipment in the CCHP system, the investment cost and the maintenance cost were taken into consideration. With the objective function to minimize the total cost, an optimal economic operation model of the integrated energy microgrid was established. Finally, an example was given to demonstrate the economic benefits and the effect of improving the renewable energy absorption capacity brought by the introduction of multi-energy supply and energy storage.

This paper focuses on deriving optimal refill rules for a multi-purpose reservoir, and aims to maximize utilization benefits under the condition of flood control safety. The entire flood season is divided into multiple sub-seasons (i.e. pre-flood season, main-flood season and post-flood season). By advancing the start of the refill period to the beginning of the post-flood season, seasonal design flows during the new refill period are estimated. A multi-objective refill operation model is proposed by combining flood control and conservation together. The simulation–optimization-test framework and hybrid multi-objective genetic algorithms are developed and used to optimize the rule curves. China’s Three Gorges Reservoir is selected as a case study and the application results show that the proposed model can increase the hydropower generation by 17.4%, decrease spilled water by 43.9%, and improve the refill probability greatly without decreasing the flood control standard and navigation probability during the refill period.

The chitosan-based biocoagulant was developed and applied to reduce the turbidity of superturbid drinking water. After a serial experiment on jar tester and a continuous flow pilot plant it was concluded that the residual turbidity of the treated water can meet the regulated value, i.e., 5 nephelometric turbidity unit easily under an economical condition. In addition to turbidity reduction, an acute oral toxicity study was conducted to evaluate the toxicity of biocoagulant itself and the water after treatment in imprinting control region mice by oral gavage. The experimental results show that no death and treatment-related clinical signals were found in animals within the 14-day study period. There were no differences in bodyweights among all treated and control mice. The results indicate that the developed biocoagulant prevailed over the current chemical coagulants not only on treatment efficiency, but also on biosafety. By applying dual coagulants operation model, the superturbid water can be treated ef...

The main purpose of this research is to develop a practical operation model for water conservation, in responding to the challenges of climate change, to propose a solution for urban drought period. This paper presents an urban drought-prevention model with allocation to prevent-drought using abundant idle raft foundation of existing buildings and the information of urban reservoir implemented by linear programming. The proposed model is developed to provide substantial demand for residential water utilisation during a period of urban drought. This operation model is of adaptable system underpinned by sustainable water management principles. The simulation and validation assumed that the water used is the rainwater and just to flush the toilets. According to the results of this research, the proposed model has been proven to be practicable and feasible for urban drought-prevention solution. Practical implications: This research illustrates the important contribution of abundant idle capacity in existing building raft foundations. This paper also shows the sustainable water management technologies and the solution for the designer, which has the opportunity to implement and adapt to the best benefit for water conservation and sustainability.

Ecological water demand is given great attention in water resources research field over the past decades. Many river administrations intend to put their hands to protect ecological flow in water resources management. But its influence on the existed interests created by reservoirs operation, become a main obstacle to carrying out the further work. Therefore the objective of this paper is to analyze the responding of cascade reservoir operation on the main Yellow River under different ecological water demand. To realize the research target, a simulation operation model of cascade reservoir was established in the study. Different ecoenvironment flow control plans were setting as the constraint conditions at the Hekouzhen cross section on the main Yellow River. Based on these Preliminary Works, the simulating regulation was put into force under different constraints, and the many result schemes were obtained by computing. Then through comparative analyzing the acquired schemes on the Yellow River, we knew that two statistics of water stress index (WSI) and ecological damage rate (EDR) was improved in 2020 level year, while other ones of water-supply guarantee rate (WSGR) and annual power generation (APG) were changing in a smaller percentage after eco-flow controlling. It is thus clear that eco-flow controlling will play an important role on ecological protection to the Yellow River within the coming 10 years, but hardly impact on cascade reservoirs power generation under appropriate actions. However, in the foreseeable future reservoir ecological regulation will relieve a great increasing of ecological damage rate from water competing, but if no drawing water resources from other basin, to meet ecological water demand of the Yellow River is still a greater difficulty.

The research progress of ecological sound operation of reservoir is Summarized into two aspects-simulation method and optimization method. Through analyzing the decisive role that flow regime plays in the river ecosystem, an effective way to realize the harmony between human and nature by operating a reservoir to control the flow regime is found out. On Lower Yalong River of China, based on the rational flow cross-sections choice according to the location and regulating ability of each reservoir, a number of flow variation control schemes are presented with respect to the ecological requirement of these two flow control points. Then, a long-term optimal operation model is established and solved to maximize the total output of power generation of the cascade reservoirs. The total power generation amount and reservoir release discharge process corresponding to each flow variation control scheme are obtained. These influences on energy output of each hydropower stations are analyzed and compared. Moreover, a power loss index for ecological water demand is defined to quantify the influences on total power generation amount of different flow control schedules.

Use of a kinetic model is made to predict parameters used in the operation and control of the activated sludge process. Mean cell residence time Θ c is the basis for comparing process parameters under different conditions of operation. Effluent organic concentration, percentage of organic removal efficiency, cell concentrations, and daily sludge production are found as functions of Θ c for different influent waste concentrations and hydraulic residence times Θ. Sludge settling data are also shown as a function of Θ c . Based on graphical relationships of the preceding parameters, a sample design and operation example is formulated to illustrate practical use of the kinetic model.

In order to research on the effect on the hydropower benefits of SiPing Hydropower station by SaLiPing hydropower station in operation, cascaded optimal operation model has been established, with the objective function of maximizing minimum power and maximizing the generated energy capacity respectively, 0.5 times power probability is selected as system power constraint. The hydropower benefits in SiPing hydropower station is calculated before and after SanLiPing in operation. The result shows that after SanLiPing in operation, the hydropower benefits in SiPing are improved through the compensation of SanLiPing, as well as its flood control condition, brought huge economic benefits to cascaded hydropower stations.