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Macrophyte-dominated eutrophication (MDE) poses great challenges to lake management. However, macrophyte overgrowth research has been mainly confined to the field of invasion ecology, and eutrophic...

This study proposes a novel method to improve the fault identification performance of transformers. First, to couple multiple factors, a high‐dimensional feature map composed of the feature gas concentrations and some associated variables is constructed. Second, the deep residual shrinkage network is revised using the updated alternating direction multiplier, and the newly constructed variable soft thresholding is proposed to eliminate constant deviations. In addition, the fast iterative shrinkage‐thresholding algorithm is adopted, as it can speed up the determination of the threshold. For the output end, the uniform manifold approximation and projection algorithm are adopted to ensure the integrity of the local optimal solution and the global solution. Compared with traditional dissolved gas analysis methods, the novel refined deep residual shrinkage network exhibits superior precision, which is justified through experiments. The results show that the recognition accuracy of the new model is more than 1.3% higher than that of the existing methods. The new method has good scalability in power applications and fault prevention.

Hydrological uncertainties are the main components of a sustainable framework in agricultural water management. Prediction of drought as a meteorological phenomenon should be considered to define the groundwater exploitation strategies. This study was conducted to develop a multiobjective-bivariate structure for reducing the soil moisture deficit and groundwater withdrawal in the Qazvin Irrigation District, Qazvin province, Iran. Therefore, non-dominated sorting theory, self-organizing particle swarm optimization and bivariate copula functions were incorporated under fuzzy uncertainty analysis. The results showed that the generalized extreme values and log-normal distribution functions had the best fitness on the drought peak and severity with Kolmogorov Smirnov amounts of 0.08 and 0.17, respectively. Furthermore, the goodness-of-fit tests were indicated the Joe joint function (MLE = 11) is the appropriate function for estimating the probabilistic values of drought characteristics. Proposed plans were to increase the water use efficiency for improving the expected yield production by an average of 20%. Furthermore, the standardized groundwater index was decreased from 1.1 to –4.3 for winter crops.

A novel model has been proposed for the methodical development and safe utilization of the lower Yellow River floodplain to provide flood control with a graded standard, sediment deposition in the partitioned zone, and the free exchange of channel runoff and sediment. The wide floodplain, which is located between the dam and the main channel, has been typically divided into three zones: high, tender, and low floodplains. Meanwhile, different ecological construction models have been suggested for each zone. This paper summarizes all related research findings; describes the overall research ideas and methodologies; expounds key issues such as land planning and utilization, sediment prediction and regulation, and multi-dimensional industrial safeguards in the lower Yellow River floodplain; and provides orientation for future research on the ecological development of the lower Yellow River floodplain. This study aims to promote the refinement of the ecological development model for the lower Yellow River floodplain and accelerate the application of research findings regarding land development and utilization of the lower Yellow River floodplain.

This research proposes a novel predictive model to improve the gas prediction accuracy in transformer oil and provide guarantees for accident prevention. First, this study constructs a cross-entropy loss function with variable thresholds and dynamic weights to reduce error transmission in the deep residual shrinkage network, enhancing the sensitivity of the normal and abnormal transformer states by the network. Second, the multiobjective particle swarm algorithm and random walk strategy are adopted to optimize the long short-term memory (LSTM) network to ensure the prediction model’s objectivity. Finally, the improved subchannel threshold depth residual shrinkage network is integrated with the optimized LSTM network. The new model can identify potential abnormal conditions in advance and preproduce an approximate fault model using a feature gas vector (similar to image recognition). Experiments verify the effectiveness of the method. Compared with the existing prediction methods, the new method can avoid blind prediction and significantly improve the prediction accuracy and efficiency, which provides essential value for transformer fault prevention.

In this study, a model for the development of the wide floodplain in the lower Yellow River Basin, in China was developed. This model includes flood control schemes using grading criteria, enables sediment deposition in partitioned zones, and allows free exchange between channel runoff and sediment. The wide floodplain located between the main channel and levees is divided into three typical regions: the tender, low, and high floodplains. Different ecological models should be applied when these floodplains are constructed. This paper describes the associated research ideas and methodology, and clarifies several key issues, including sediment prediction and regulation, land planning, land use, and a multi-dimensional framework of safeguard measures for industries on the lower Yellow River floodplain. A refined ecological development model is proposed for the lower Yellow River floodplain, and future work on ecological and sustainable development of the lower floodplain is suggested. To establish a comprehensive system integrating runoff and sediment resource regulation in the Yellow River Basin, future work should focus on runoff and sediment exchange mechanisms in the wandering lower reaches. Furthermore, it is necessary to improve theories on floodplain planning and ecological construction, and these theories should be integrated with the research findings on land development across the lower Yellow River floodplain.

It has been over 110 years since China’s first hydropower station, Shilongba Hydropower Station, was built in 1910. With the support of advanced dam construction technology, the Chinese installed capacity keeps rising rapid growth, hitting around 356 GW nationwide by the end of 2019, and the annual electricity production exceeds 10,000 TWh. At present, China contributes to 25% of global installed hydropower capacity, ranking first in the world for 20 consecutive years since 2001 and surpassing the combined of the 4 countries ranking second to fifth. This paper reviews China’s progress in the context of global hydropower development and examines the role of technological advance in supporting China’s hydropower projects, especially dam construction technology. China is currently actively promoting the “integration of wind, solar, hydro, and coal power generation and energy storage” and building a smart grid of multi-energy complementary power generation. New technologies and new concepts are expected to continue to lead the world’s hydropower development trends.

Water-energy-food (WEF) are essential for human survival and development and they interact complexly. The research on Water-energy-food-coupling security risk (WEF-CSR) is crucial to promoting multi resource collaborative management. In this study, a comprehensive index system was constructed using three dimensions: reliability (Ra), coordination (C), and resilience (Rs). We selected the middle and upper reaches of the Yellow River Basin in China to study WEF-CSR conflicts, coupled with the Copula method of risk probability calculation. The results showed that: 1) from 2005 to 2021, the WEF-CSR index in the study area showed a progressively increasing trend, with a mean value of 0.49 in a critical safety state and lower values in the upper reaches of Ningxia and Gansu provinces. 2) The Ra-indexes in the criterion layer is not clearly affected by resource endowment conditions between annual periods; C-indexes are growing rapidly, with their annual growth rate four times as fast as the Ra-indexes, and Rs-indexes growing at about 2.7 times faster. 3) "Energy consumption per capita, carbon emissions, and water-related indicators" are the six main limiting factors, with a combined impediment degree of over 35 %, water resources are major constraint. 4) The Ra-C, C-Rs, and Ra-C-Rs indexes are well fitted by Clayton copula, and the C-Rs indexes are well fitted by Frank copula. The three-dimensional joint distribution risk probability, Ra-C-Rs (Ra ≤ 0.4, C ≤ 0.4, Rs ≤ 0.4) is 0.29. When the Ra or C indexes increases, the probability of unsafe Rs rises to 40 %-50 %, meaning future development must emphasize synergy, especially in Rs. In future, the five provinces in the middle and upper reaches of the Yellow River should focus on reducing energy pressure, improving water shortage conditions, and enhancing the overall resilience to avoid single-factor adverse conditions affecting WEF's coordinated and sustainable development.

The tournament operator genetic algorithm (TGA) often shows poor convergence and easily gets trapped in a local optimum when solving optimized reservoir scheduling problems. The selection operation is the most important operation determining an algorithm’s convergence; therefore, this study proposes a proportional reproduction selection-based operator genetic algorithm (RGA) and a steady-state reproduction selection-based operator genetic algorithm (SGA) as alternatives to TGA. This study used TGA, RGA, and SGA to solve the maximum power generation model for the Gezhouba hydropower station, the largest runoff hydropower station in the world. Then, by using the maximum hydropower station output under a given typical runoff scenario as the optimization criterion, this study evaluated the optimized solution performance of the GA using different selection operators. The results show that TGA, SGA, and RGA can be applied to solve the short-term reservoir scheduling model. As the number of iterations increases, the hydropower station output optimized by these three GAs increases. Based on the maximum power generated by the Gezhouba hydropower station, SGA and RGA provide better results than TGA, and between SGA and RGA, the former provides better results.

A method is presented for optimal load dispatch in large-scale hydropower plants using a genetic algorithm integrated with simulated annealing. The genetic algorithm overcomes dependence on an init...

The forecasting accuracy of downstream water levels greatly impacts the economic operation of reregulating hydropower stations. If present, large errors in water level forecasting may require the hydropower station to discard water, which decreases the revenue from hydropower generation. Especially when the reregulating hydropower station undertakes the task of peak load regulation of the power grid, its power output may change drastically over a short period of time. Such large changes in the discharged flow of the hydropower station may inevitably cause an unsteady flow, which can lead to large fluctuations in the water levels of downstream rivers. In this case, the current forecasting methods, such as standard rating curves and empirical formulae, may inevitably result in large deviations when forecasting the change in the downstream water level. In order to reduce the volume of water discarded as a result of forecasting errors, a back propagation neural network-based forecasting model for downstream water levels of a reregulating hydropower station was constructed. The model enabled the direct, accurate, real-time forecasting of changes in downstream water levels by using measurable operation data from a hydropower station and process data on downstream water level changes. This method was applied to the actual hydropower generation dispatch of the Gezhouba Hydropower Plant in China. The results showed that as the peak load regulation volume increased, the forecasting errors of two conventional methods (standard rating curves and empirical formulae) became continuously superimposed. However, the water level forecasting error of the neural network-based method was small and could fully meet the real-time dispatching requirements of the hydropower station. In particular, under large peak load regulations, the maximum absolute values of the forecasting errors of the two conventional methods were close to 1 m, while that of the neural network-based method could be controlled within 0.3 m.

Intense vibrations in hydraulic turbine generator unit draft tubes lead to a run-out of the unit shafting and threaten its safe and stable operation. Correct maintenance is therefore important for the safe operation of such units. This study involves assessing the condition of the turbine generator unit by extracting the feature information of its vibration signals. Based on previous research, we present an enhanced Hilbert–Huang transform (HHT) method with an energy-correlation fluctuation criterion to extract feature information and effectively verify the method with simulated signals. An inspection application based on the signal from a vortex strip in the draft tube of a prototype turbine under suboptimal operating conditions indicates that this method is more effective than the traditional one, with a better component identification capability and better suited to the analysis of the complex and dynamic feature information of hydro turbines.

The Jinghe River remains the major sediment source of the Yellow River in China; however, sediment discharge in the Jinghe River has reduced significantly since the 1950s. The objective of this study is to identify the causes of sediment yield variations in the Jinghe River Basin based on soil and water conservation methods and rainfall analyses. The results revealed that soil and water conservation projects were responsible for half of the total sediment reduction; sediment retention due to reservoirs and water diversion projects was responsible for 1.3% of the total reduction. Moreover, the Jinghe River Basin has negligible opportunity to improve its vegetation cover (currently 55% of the basin is covered with lawns and trees), and silt-arrester dams play a smaller role in reducing sediment significantly before they are entirely full. Therefore, new large-scale sediment trapping projects must be implemented across the Jinghe River Basin, where heavy rainfall events are likely to substantially increase in the future, leading to higher sediment discharge.

With the economic growth, continuous global environment deterioration, and increasingly serious water resources shortage, droughts have become more and more serious and produced great impacts on both the regional ecology and sustainable economic development. This paper has established the &ldquo, green, blue, yellow, orange, and red lights&rdquo, as the early warning grades for agricultural droughts. By using the two influencing factors, namely precipitation and soil moisture, this paper has established the drought assessment index evaluation model using weighted coupling method. It has carried out the analogue simulation of the early drought warning based on the Jinghui Channel&rsquo, s 2013 water source situations. The soil moisture in January and February is relatively ideal, and the actual early drought warning is expressed by the &ldquo, green light&rdquo, The soil moisture deficit is comparatively serious in March, but the situation concerning water inflow is ideal with the &ldquo, Actually, the early warning signal is basically consistent with the soil moisture drought degree between April and August. The actual early warning is expressed by the &ldquo, as well, but the soil moisture is not so ideal, however, this is the seeding time of the winter wheat so the lack of soil moisture has no impact on the crops output. In November and December, the winter wheat is at the growth and development stage and does not need much moisture. At this stage, the soil moisture is relatively poor. By integrating the time effects into the early drought warning system, this paper provides administrators of irrigation areas with a scientific decision-making based on the drought control measures.

Glaciers are a critical freshwater resource of river recharge in arid areas around the world. In recent decades, glaciers have shown evidence of retreat due to climate change, and the accelerated ablation of glaciers and associated impacts on water resources have received widespread attention. Glacier variations result from climate change, so they can serve as an indicator of climate change. Considering the climatic differences in different elevation ranges, it is worthwhile to explore whether different responses exist between glacier area and air temperature in each elevation zone. In this study, we selected a typical arid inland river basin (Sugan Lake Basin) in the western Qilian Mountains of Northwest China to analyze the glacier variations and their response to climate change. The glacier area data from 1989 to 2016 were delineated using Landsat Thematic Mapper (TM), Enhanced TM+ (ETM+) and Operational Land Imager (OLI) images. We compared the relationships between glacier area and air temperature at seven meteorological stations in the glacier-covered areas and in the Sugan Lake Basin, and further analyzed the relationship between glacier area and mean air temperature of the glacier surfaces in July–August in the elevation range of 4700–5500 m a.s.l. by the linear regression method and correlation analysis. In addition, based on the linear regression relationship established between glacier area and air temperature in each elevation zone, we predicted glacier areas under future climate scenarios during the periods of 2046–2065 and 2081−2100. The results indicate that the glaciers experienced a remarkable shrinkage from 1989 to 2016 with a shrinkage rate of −1.61 km2/a (−0.5%/a), and the rising temperature is the decisive factor dominating glacial retreat; there is a significant negative linear correlation between glacier area and mean air temperature of the glacier surfaces in July–August in each elevation zone from 1989 to 2016. The variations in glaciers are far less sensitive to changes in precipitation than to changes in air temperature. Due to the influence of climate and topographic conditions, the distribution of glacier area and the rate of glacier ablation first increased and then decreased in different elevation zones. The trend in glacier shrinkage will continue because air temperature will continue to increase in the future, and the result of glacier retreat in each elevation zone will be slightly slower than that in the entire study area. Quantitative glacier research can more accurately reflect the response of glacier variations to climate change, and the regression relationship can be used to predict the areas of glaciers under future climate scenarios. These conclusions can offer effective references for assessing glacier variations and their response to climate change in arid inland river basins in Northwest China as well as other similar regions in the world.

Scientific assessment provides important tools for the sustainable use of water resources. This paper applies the set pair theory of entropy weight to evaluate the uncertainty involved. A preliminary classification of samples is conducted by calculating the connection degree of each evaluation index, and then uniform, differential and confrontational analyses of set pairs are carried out on the samples to identify their level. In identifying the weight of each evaluation index, the entropy value theory of information theory is introduced into the model. Combined with Tarim 2004 to 2007 water resource data, an evaluation of the sustainable water resource utilization in this region is made from the social and economic, water resource and ecological environmental water resource evaluation index system. The results show that the development and utilization of water resources in the Sanyuanliu region of Tarim are saturated, and the utilization of water resources in the Hotan region (III), Aksu region (III) and Kashgar region (III) appears to be unsustainable. After a comparison with other methods, it is concluded that the evaluation result provided by the method is reasonable and objective.

Watershed is an important existing form of water, with various functions such as water supply, irrigation, fishery, tourism, and flood prevention, playing a major role in the daily production and lives of residents and regional social and economic development. As a brand new management objective, watershed development is a significant means for supporting and ensuring the sustainability of social, economic and environmental development. This paper elaborates the importance of preserving the ecological and hydrological connections of river systems to sustain their healthy life cycle, as a harmonious relationship is essential for the current and future watershed management. By emphasizing the importance of the watershed ecological and environmental management and restoration, on the basis of the existing research results, this paper sums up the basic concepts and connotation of the ecological operation of reservoirs, analyzing the research achievements and existing problems of ecological operation study, and resulting in a fundamental framework of ecological operation model based on the multiscale coupling mechanism, objective coordination mechanism, generative mechanism of characteristic flows and operation scheme of the rolling correction mechanism.

This study proposes and tests a new approach to detect and analyze changes in flood regime using a distributed hydrological model (EasyDHM), using the Second Songhua River basin, China, as a case s...

The joint operation of cascaded reservoirs can generate various compensation benefits. How to calculate all compensation benefits scientifically and fairly, and how to share these benefits reasonably, will be of great importance for the sustainable development of the basin and for the rolling development of a cascaded reservoir of a hydropower station. This article examines the joint operation of Longyangxia and Liujiaxia reservoirs at the upper reaches of the Yellow River in China. To study the reservoir compensation benefits, the authors have built a compensative regulation model for the joint operation of the reservoir group. The electricity generation compensation economic effects of the joint operation of the Longyangxia and Liujiaxia reservoirs in 2005 were calculated. The results showed that the joint operation of cascaded reservoirs can generate remarkable economic benefits.

The Middle Route of the South-to-North Water Diversion Project is important for China. Any sudden water pollution accident along the route would threaten normal water supply. We studied four techno...

Flash floods cause extensive loss of property and human life. Early warning systems present a more efficient approach to flood prevention and mitigation than engineering measures. This article revi...

The completion of Shuibuya, the last hydropower station to be constructed in the Qingjiang cascade, signifies China's successful development of the world's largest mixed cascade hydropower generation system. Joint operation of such cascaded hydropower stations is considered necessary to improve hydropower output in China. In this study, two modeling methods – routine and optimal operations – were adopted, based on existing rules of reservoir operation, to determine the effects of joint operation. To investigate the realistic and potential effects, the two models were computed using observed runoff data (1951–2009). The potential effects were identified by comparing the total hydropower generation two single cascades and their cogeneration. Under the routine operational mode, the incremental power generation of joint operation would be 5.73 × 108 kWh, an increase of 5‰ compared to isolated operation. However, even in isolation, if reservoir operation is optimized through the dynamic programming algorithm, the incremental power generation of the cascade would be 42.24 × 108 kWh, which is seven times that of joint operation with routine reservoir operation (5.73 × 108 kWh). The results showed that, under current reservoir operating rules, there is little room for improvement in hydropower generation, although joint operation could increase hydropower generation to a certain extent, especially in the reservoirs' refill and release stages. China must amend its existing operational mode for reservoirs to enhance the economic benefits of cascade hydropower stations. Furthermore, to meet increasing demands for both water and energy, carefully considered planning of constructing clusters of these stations is required.

China’s coal-based energy supply inflicts destructive damage upon the ecological environment, though it has simultaneously safeguarded the rapid development of China’s economy in recent decades. To promote ecological recovery and accelerate the adjustment of its industrial structure, China is poised to fully implement a total coal consumption cap through the “13th Five-year Plan” (2016–2020). This study assesses the feasibility of this strategy from the perspective of water resources, exploring and predicting outcomes from 2012 to 2050. After first measuring the water resources demands for the life-cycle of coal, this study then analyzes the destructive effects on water resources from coal production through to consumption, before finally evaluating the water conservation synergy effects under different plans for capped coal consumption. The results reveal that implementing a total coal consumption cap could reduce the adverse effects on the water resources system due to coal mining, washing, conversion, and utilization by comprehensively promoting conservation and protection of water resources. The study directly compares the two cap strategies of “behave as usual” and “reinforced total consumption control,” finding that neither of these strategies can totally satisfy China’s existing requirements for water resources management. In future, China’s total coal consumption will exceed the feasible scale of coal mining as restrained by total water use limits, and the required quantity of water for conversion and utilization of coal will also exceed its water use limit. Therefore, to achieve coordinated progress between the development of the coal-related industry and sustainable utilization of water resources, the Chinese government urgently needs to further reinforce total coal consumption controls and actively popularize the application of water-saving technology. In addition, the study estimates the damage to water resources due to China’s coal consumption, determining the value of lost water resources per ton of coal consumption nationwide to be 52.76 yuan. If all of China’s coal enterprises could apply water-preserving mining technology and make full use of mine water for production, the loss of water resources nationwide per ton of coal consumption could be lowered to 40.91 yuan. Therefore, the study advocates the combination of a market price adjustment mechanism and a macro total control strategy to maximize the synergic benefits between energy and water resources in China.

Calibrating the coefficients of discharge formulas of gates has great significance for the simulation and control of water flow. By investigating three discharge formulas derived from the energy equation and one discharge formula derived from dimensionless analysis of radial gates, the new parameter identification models for these discharge formulas were established using the least squares method, and the coefficients of discharge formulas were obtained. Followed by that, these discharge formulas of radial gates were applied through a case study. The results showed that the mean relative errors of the four formulas were 18.99%, 34.26%, 24.10% and 21.11%, respectively; while the mean relative errors were reduced to 3.54%, 3.54%, 1.90% and 1.09% by the use of parameter identification technique, respectively, indicating that the accuracy was greatly improved. The results proved that the parameter identification method may have potential application to improve the accuracy of calculating the discharge under the radial gates, and can also be applied to the sluice gates.

This paper presents a practical genetic algorithm (GA)-based solution for solving the economic load dispatch problem (ELDP) and further compares the performance of the improved GA (IGA) with that of dynamic programming (DP). Specifically, their performance is comprehensively evaluated in terms of addressing the ELDP through a case study of 26 turbines in the Three Gorges Hydropower Plant with a focus on calculation accuracy, calculation time, and algorithm stability. Evaluation results show that the improved GA method can significantly reduce the ineffectiveness of the GA in current use and could avoid the running of the turbines in the cavitation/vibration zone, thereby ensuring the safety of the turbines during generating operations. Further, the analysis comparing the performance of the IGA and DP show that the IGA is superior to DP when a small number of turbines are involved. However, as the number of turbines increases, the IGA requires more calculation time than DP; moreover, its calculation accuracy and convergence rate are significantly reduced. It is difficult to guarantee the stability of IGA in high-dimension space even though the population grows, on account of the exponential expansion of the calculation dimension, the algorithm’s premature convergence, and the lack of a local search capability. The improvement of the GA as well as the evaluation method proposed in this paper provide a new approach for choosing and improving optimization algorithms to solve the ELDP of large-scale hydropower plants.

The presence of native adsorptive substances (NAS) cause uncertainties in the analysis of sediment phosphorus (P) adsorptive capacity. Therefore, HCl washing pretreatment is now used to clean sediment NAS. However, uncertainties still exist because the concentration (C) varies widely, from pH 3.5–12 mol/L, among studies. In this study, sediment samples from four sites were washed with HCl at different concentrations (C), and then analyzed to evaluate washing effects on the native absorptive substances (phosphorus, metals, and organic matter), the phosphorus equilibrium adsorption capacity (EAC), and sediment skeleton erosion. Study results reveal that washing efficiency, sediment skeleton erosion, and adsorption capacity varied with C. Micromorphology analysis showed that sediment erosion increased with increasing C; the optimum C value is 0.0–1.0 mol/L (STG1) level based on its small negative impact on the sediment skeleton. Additionally, NAS analysis further showed that washing efficiency increased with increasing C. Most native adsorptive substances (NAP, Fe, Al, Ca, and OM) were released when the HCl concentration was in the range of 0.5–1.0 mol/L. Therefore, 0.5–1.0 mol/L (in STG1) may be the best choice for sediment washing because of its fairly satisfactory washing efficiency. Finally, P equilibrium adsorption capacity (EAC) analysis showed that the sorption capacity varied greatly with C at 0.5–1.0 mol/L, due to the erosion of the sediment skeleton. Therefore, C at 0.5 mol/L is the optimal concentration because the skeleton erosion was minimized when C decreased to the minimum point in the 0.5–1.0 mol/L range. The HCl washing pretreatment (C = 0.5 mol/L) can also be used for analyzing other basic physicochemical substances (P, Ca, OM, Fe, Al). Our findings are an important step in providing important data for ecological restoration of wetlands, streams, rivers, lakes, and reservoirs, especially for those controlled by the internal source.

At present, the urbanization and energy consumption complex system enters the stage of ultimate development. So it is not certain about synergistic development. From the perspective of causal feedback mechanism system and based on the mechanism of various elements of urbanization and energy consumption, this paper explores the path of synergistic development of urbanization and energy consumption, simulates the baseline scenario from 2005 to 2020 through establishment of the SD model of urbanization and energy consumption complex system, predicts the future behavior of the state variable when the control variable changes in the system through simulation, seeks for interaction and interrelationships between various elements in the process of evolution and development, and finally puts forward three paths to optimize the synergistic development of urbanization and energy consumption which are population transfer, industrial upgrading and technological improvement, which provides some references and foundation for making decisions of synergistic development of new urbanization and energy consumption.

In order to ensure economic development, China plans to build fourteen large-scale coal bases during the period of the 13th Five-Year Plan (2015–2020). Coal production and washing, coal-fired power generation, and coal chemistry are the major developing industries in relation to the coal bases. In this study, we predict that by 2020, the newly increased water demand of these three industries will reach 3.8 billion m 3 . Even if water saving measures are reinforced, the newly increased water demand will still be 2.3 billion m 3 . Water resources will become the weak link, restricting the energy industry development of coal bases in areas such as Xinjiang, Ordos, Northern Shaanxi, and Huanglong. In addition, according to current plans, the scale of development for coal bases in water-deficient areas such as Northern Shaanxi, Huanglong, Shendong, Eastern Mongolia, Eastern Ningxia, and Xinjiang is expected to increase substantially. This will drive increased water demand, intensifying competition for water among different industries and regions in the context of a limited capability to guarantee regional water resources. Severe water resources challenge China’s energy development strategies is foreseeable, and if we are to guarantee the water supply required by these coal bases, it is necessary to begin expanding supply and controlling demand now.

Water conservancy project bidding involves many aspects including nature, society, economy, and environment. In water conservancy project bidding evaluation, both quantitative and qualitative indexes are involved; moreover, different targets are often incommensurable and compete with each other. Scientific decision-making in bidding evaluation is key to linking the stages of project bidding; selecting an appropriate contractor is not only conducive to improving the project quality, but also helpful to achieve the goal of saving on investments. This paper intends to study the problem of multi-target group decision-making in project bidding processes via the use of the mathematical method of fuzzy clustering. Bidder 3 is finally chosen as the most suitable contractor for the construction of this project by determining the score matrix and index weight vector of the four bidders concerned. Results have indicated that the aforementioned method is more reasonable and reliable; thus, the bidding evaluation decision is more scientific.

Optimizing energy structure to reduce carbon intensity is an effective way to build the low-carbon city development model. To assess the contribution potential of energy structure optimization in order to achieve the carbon intensity target in Hangzhou City, the component data prediction, scenario prediction, GMI (1, 1) model and other multidisciplinary approaches were adopted to predict the carbon intensity trends in the above said City from 2014 to 2020. This contribution potential is evaluated based on 9 kinds of combined scenarios. The results show that: 1. Under the same economic growth rate, with the increase in energy structure adjustment range, the carbon intensity “decline range” becomes larger, and the higher is the “contribution potential” of energy structure optimization to achieve the carbon intensity target. 2. Within the same range of energy structure optimization, the economic growth rate is lower, the carbon intensity “decline range” is smaller, and the “contribution potential” of energy structure optimization is higher for the same carbon intensity objective. By optimizing energy structure and industrial structures adjustment, the technology upgrading for carbon emissions and the scientific and technological level of the systematic industrial policies are more conducive to supporting the realization of low-carbon city.

China is a country with a serious water shortage. Irrigation water accounts more than 60% of total water use. With the nation’s population forecasted to peak approximately 2030, the production of food for additional people will require more water resources, which exacerbates water shortages. North China is a typical case for studying water-food nexus because water shortage has become a primary factor in restricting food production. From the perspective of virtual water, the study calculates the changing trend of the virtual water (VW) flow related to grain transfer in China, for which three primary crops of China, including rice, wheat and maize, are considered. The results demonstrate the impact of changing the spatial patterns of grain production on water resource utilization is large, and water resources are redistributed related to grain trade. Northern China imports water-intensive products from southern China and exports water-extensive products, and the VW flow from North to South from 2004 to 2013 was approximately 42.6 billion m3 per year, about 10.2 billion m3 irrigation water was transferred per year which accounts for about 10% of the water consumption for crop production in the North. Although the South–North Water Diversion Project, a mega-engineering scheme constructed from the Yangtze River Basin to the Huang-Huai-Hai River Basins, alleviates water pressure on the North to a certain extent, it is insufficient for exporting to provinces, and water resources for meeting grain production in the North is problematic. Based on the results, this paper suggests that virtual water flow among provinces should be linked to water resource management. The next step in water management should focus on water demand management, rather than increasing crop trade from the North to the South, which is governed by governmental policies and economy.

This study analyzed the contributions of output, technological, and structural factors to industrial water use. Using Tianjin, a National Water-Saving City in China, as a case study, we adopted the refined Laspeyres and Logarithmic Mean Divisia Index models to decompose the driving forces of industrial water use changes. The decomposition results of both models show that output and technology have long-term, stable effects on industrial water use in Tianjin. Output stimulates water use, leading to an average annual growth of 7700 × 104 m3, while technology inhibits water use, with an average annual reduction of 7900 × 104 m3. However, the effects of structure on industrial water use are not stable. During the study period, the stimulation and inhibition of industrial water use alternated; however, stimulation was dominant after 2008, implying increased partiality of the industrial structure toward high water use. The results of the study contrasted the hypothesis that Tianjin's primary goal in restructuring local industries over the past decade has been the achievement of water use efficiency. Reduced water use may have resulted from Tianjin's development with targets other than water-savings.

To ease the growing water crisis, Tianjin has pioneered the implementation of the most stringent water management system in China. Presently, Tianjin achieves the highest industrial water efficiency in China. In 2010, Tianjin was named the first “Water-Saving Society Construction Demonstration City” by the Chinese central government. To provide a theoretical basis and supporting data for the construction of “national water-saving cities”, a decomposition method is adopted to quantitatively analyze changing industrial water use in Tianjin. Data are decomposed using a refined Laspeyres model, highlighting changes associated with industrial restructuring, followed by detailed sectoral analysis. There are two distinct stages of industrial water use: before 2008, industrial water use decreased, driven predominantly by technological advances; after 2008, higher industrial output led to greater industrial water use that overshadowed the water savings achieved by technological development. Nevertheless, water efficiency showed limited improvement, despite the increasing industrial scale and output of certain industrial sectors. The findings show that in Tianjin, reduced industrial water use is not the primary objective, but an associated combination of industrial development and structural adjustment.

Changes in industrial water use are of the utmost significance in rapidly developing countries. Such countries are experience rapid industrialization, which may stimulate substantial increases in their future industrial water use. Local governments face challenges in formulating industrial policies for sustainable development, particularly in areas that experience severe water shortages. This study addresses the factors driving increased industrial water use and the degrees to which these factors contribute, and determines whether the trend will change in the future. This study explores the options for quantitative analysis that analyzes changes in industrial water use. We adopt both the refined Laspeyres and the Logarithmic Mean Divisia Index models to decompose the driving forces of industrial water use. Additionally, we validate the decomposition results through a comparative study using empirical analysis. Using Tianjin, a national water-saving city in China, as a case study, we compare the performance of the two models. In the study, the driving forces of changes in industrial water use are summarized as output, technological, and structural forces. The comparative results indicate that the refined Laspeyres model may be preferable for this case, and further reveal that output and technology have long-term, stable effects on industrial water use. However, structure may have an uncertain influence on industrial water use. The reduced water use may be a consequence of Tianjin’s attempts to target water savings in other areas. Therefore, we advise the Tianjin local government to restructure local industries towards water-saving targets.

The inverse relationship between water and sediment is hindering the regulation of sediment in silt-laden rivers. Under natural conditions and insufficient water flow, sediment deposits along river channels, resulting in the accumulation of suspended river sediments above the ground level on both sides of the river. Then, during flooding, dam collapse and overflow can easily occur, threatening the life of residents in floodplain. The operation of upstream reservoirs to maximise the sediment transport capacity of downstream rivers into the sea is deemed the best strategy for the management of silt-laden rivers. However, as incoming water and sediment form a dynamic system, optimising the operation mode of reservoirs has become the most severe challenge in the field. This study proposes a method to remodel the water–sediment relationship of natural rivers by optimising the reservoir operation. First, data were collected and analysed to investigate sediment transport in the downstream river channel and the response relationship between erosion–deposition. Then, an empirical equation for calculating the desired incoming sediment was derived, and the threshold for sedimentary transport balance in the lower reach of silt-laden rivers was determined through mathematical modelling. Finally, the reservoir operation mode was optimised within the threshold range to study the discharge process of the reservoir with the highest sediment transport efficiency downstream. The Yellow River in China exhibits the highest sediment concentration worldwide and was used as a case study to verify the practicability of the proposed method. The critical threshold for sediment transport balance in the lower Yellow River was determined to be 250 million tons. The results demonstrate that the proposed method improved the sediment transport capacity of the lower reaches of the Yellow River. Moreover, it reduced the siltation of the XiaoLangDi Reservoir and the lower reaches of the Yellow River. The XiaoLangDi Reservoir can be jointly operated with the Guxian Reservoir, which is under construction and is expected to maintain the bankfull discharge of the lower reaches of the Yellow River at 4000 m3 for a long time. The optimisation process described in this study can be used to improve the management of silt-laden rivers.

In this paper, a processing conversion and parallel control platform (PCsP) is proposed for transitioning serial hydrodynamic simulators to a cluster-computing system. We previously undertook efforts to promote the research and development of this type of platform and to demonstrate and commercialize it. Our PCsP provide distributed and parallel patterns, a centralized architecture, and user support. To validate our employed methodology and highlight its simplicity, we adopted the technology in various applications based on multi-grid algorithms. The methodology was shown to be reliable and feasible across computational domains, partitioning strategies, and multi-grid codes. Furthermore, its effectiveness was demonstrated using a complex engineering case in addition to code based on slightly less complex mathematical models. Eventual transition to a cluster-computing system will require further investigation of the impact of different model combinations on calculation accuracy, efficiency of operating models, and PCsP functional development.

This study identifies the driving forces behind maximizing Tianjin’s industrial water use efficiency in China. For this purpose, a decomposition method is developed to quantify the degree of the impact of each factor. The results show that industrial expansion was responsible for an increase in annual water use of 78 million m³, while technical advances and water efficiency measures contributed annual water savings of about 76 million m³. Further, the results highlight that Tianjin has not considered the rise in water efficiency to be the primary goal of restructuring local industries over the past decade.

Coal is China's most important primary energy source, and is supporting the rapid economic growth going on there. However, the reverse geographical distribution of coal production and consumption results in a high cost of coal transportation and low efficiency of coal utilization. To ease the pressure on coal transportation, and to mitigate pollution in eastern coastal regions, China has kicked off a strategic west–east transfer of energy industries that requires the movement of coal power projects to the arid northwest regions. Under this strategic framework, the regulation is focused on “clean production”, “consumption reduction” and “reuse”, rather than conservation and protection of water resources. This study found that the northwest areas are unable to accommodate fully the planned scale of coal-fired power industry. Moreover, the subsidiary chemical industry, even if the scale of electric power development is determined according to the need for coal production, is problematic because the current water demand for the coal industry has exceeded “allowed water withdrawal”. Given limited water saving potential and the huge demand-and-supply gap, it is also unrealistic to balance water demand by combination of water conservation in the power industry and water right diversion from agriculture. This study on the synergies between energy and water is urgently needed, in order to provide scientific and technological support for laying out new energy industries. A critical change should involve conciliation of conflicting policies or plans before implementation begins.

China is an energy starved country that has faced a severe energy crisis for the last few decades. In response to China’s increasing dependence on non-renewable fuels, the Chinese government has discussed current and potential biomass energy resources as well as energy conversion and promotion policies. Bioethanol production has proven to be environmentally friendly and energy-efficient and is a potentially important source of renewable fuels. However, the uneven distribution of water and the implementation of the Three Red Lines water conservation policies may limit the development of bioethanol in China. From the perspective of water footprint (WF), this paper analyzes the water requirements of producing bioethanol from crop straws, and shows that water consumption in the bioethanol conversion stage is less than that in the crop growth stage; in other words, producing bioethanol from crop straws may be more water-efficient than that from grains or non-grain crop because water that would be consumed for grain growth is already being allocated to the agricultural sector. There is an abundance of crop straws of approximately 150.71 million tons that can be used for bio-ethanol production in China; if converted, 41.83 billion L ethanol would be produced annually, and an amount equal to 4 times China’s fuel ethanol production in 2014. According to a crop straws and water resource conditions, the provinces of Jilin, Shandong, Henan and Sichuan are the best for developing bioethanol from crop straws however, variations in the local availability of water resources and crop straws prevent us from drawing immediate conclusions about which crop straws would be most suitable for bioethanol production in China.

As floods could be effectively forecasted by distributed hydrological model, their study and application became the key points of flood forecasting and early warning. Based on high performance computing clusters, a parallel flood forecasting and warning platform with the characteristics of partition, classification, and complicated process coupled was established to forecast and warn flood across China, especially for flash flood in China. In addition, the platform was based on China Flash Flood Hydrological Model (CNFF-HM). It used files (not MPI), which based on a shared hierarchical storage system, to pass message to control the start and stop of simulation processes, and the rapid communication among simulation processes was realized; pre-allocation and dynamic allocation methods was together applied to manage the resource of the high performance computing clusters; the automatic switch among different time scale models was realized by simulation driven strategy based on rainfall events; the reboot framework was designed to deal with the process crash and delayed rainfall data. The effectiveness and stability of the platform has been tested by the flood events of 2017. Finally, a case of Weishui catchment in Hunan Province was shown.

The Thirsty Energy initiative of the World Bank assists countries to address water and energy planning challenges in an integrated manner. The first two Case Studies for South Africa and China have been completed. The approach to developing “water-smart” energy planning models was different in the two Case Studies, with key findings and important insights arising from each. The most fundamental conclusion from both studies is that policies being pursued to mitigate climate change impacts reduce both CO2 emissions and water needs by the energy sector—with only modest increase in energy system cost, and that including the supply and cost of water has a dramatic effect on the upstream technology choices. For example, government mandated policies forcing dry cooling for new coal-fired power plants was reaffirmed as wise and appropriate, though at odds with achieving Nationally Determined Contributions (NDC) which quickly disincentivizes the use of coal while promoting renewables and nuclear, as a major step towards achieving below 2 °C emission reductions. Thirsty Energy also examined the influence of climate change on energy and water planning, where results for the two Case Studies proved to be very different, as water availability in China’s northern Energy Bases may actually increase slightly, while in South Africa the water system is stressed forcing more dramatic changes in the energy sector.