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In the current society, the frequent occurrence of urban floods has attracted wide attention in China. Based on the research literature of urban flood disaster in CNKI Chinese periodical database from 2001 to 2021, this paper used Citespace and SATI3.2 software to analyze the annual publication frequency, journals and institutions, research hotspots, research frontiers and development trends of urban flood disaster related literature. The results show that the urban flood disaster has always maintained a high heat, involving many disciplines and cross phenomenon; the publishing institutions are mainly concentrated in design and planning colleges and universities; sponge city construction, low-impact development and risk assessment are still the main research hotspots. Resilient city, vulnerability and coupling model will be the future research trend. [ABSTRACT FROM AUTHOR]

The middle reaches of the Yellow River is an important national ecological function area and energy base. It is an arduous task to prevent and control soil erosion and protect ecology. In view of the problems of large quantity of soil and water conservation supervision work area, insufficient supervision ability and weak timeliness of traditional supervision way in the Yellow River Basin, this paper puts forward some countermeasures for establishing the pilot demonstration zone of high quality supervision of soil and water conservation in the contiguous area of Shanxi, Shaanxi and Inner Mongolia, and probes into its working mechanism and mode: First, the goal of innovation management is to take the lead in implementing non-violation projects, Second, the goal of innovation cooperation is to jointly build a working system, and build a working mechanism with consistent goals, self-awareness of actions, and coordinated efforts, Third, the endogenous motivation of innovation, taking self-discipline as the core to promote the overall level of credit for soil and water conservation, Fourth, leaders at all levels, construction units, young people and the general public should improve the cognition and ability of ecological civilization in soil and water conservation to achieve the unity of knowledge and practice, Fifth, the connotation of innovation evaluation will be improved to comprehensively enhance the level of scientific and technological support, Sixth, digital empowerment, scientific classified management and innovative smart platform will enable production and construction projects to achieve smart technology guidance, smart tracking, smart early warning. Reset [ABSTRACT FROM AUTHOR]

In order to explore the internal relationship between digital economy and green total factor productivity of manufacturing industry in the Yellow River Basin, this paper empirically analyzes the impact of digital economy on green total factor productivity of manufacturing industry in the Yellow River Basin by using systematic GMM model and panel threshold model based on panel data of 73 prefecture-level cities in the Yellow River Basin from 2011 to 2020. The research shows that digital economy can significantly promote the improvement of green total factor productivity of manufacturing industry in the Yellow River Basin, and this promoting effect is nonlinear with marginal increasing. Further investigation shows that the impact of digital economy on green total factor productivity of manufacturing industry has a single threshold effect based on opening to the outside world and government support. Heterogeneity analysis shows that digital economy has a more significant effect on the improvement of green total factor productivity of manufacturing in the middle and downstream regions. [ABSTRACT FROM AUTHOR]

Taking the built, under construction and planned hydropower stations in the upper and middle reaches of the Yellow River and their surrounding wind and light resources as the object, based on the output characteristics and complementary characteristics of hydropower, wind power and photoelectric power, and based on the principle that the access of wind power and photoelectric power does not increase: the abandoned water of hydropower, and the abandoned wind and light rate were controlled economically, the research on the integrated configuration and operation of hydropower, wind power and photovoltaic power generation in the main stream of the Yellow River was carried out. Combined with the complementary operation characteristics, it made full use of the regulation capacity of hydropower, improved the utilization efficiency of transmission channel, and coordinated the local consumption and transmission. On the basis of technical feasibility and economic rationality, this paper constructed the hydropower, wind power and photoelectric configuration model and economic analysis model of the main stream of the Yellow River. Through model analysis and calculation, this paper put forward the economically reasonable proportion scheme of hydropower, wind power and photoelectric installation scale, and put forward the development goal and layout of water scenery integration in the main stream of the Yellow Rive r in 2025 and 2035. [ABSTRACT FROM AUTHOR]

The research object of this paper was a cemented sand gravel dam in the design stage. The foundation overburden at the dam site was sanely pebble soil layer, and the dam body was cemented sand gravel. Exploring its stress deformation law and reasonable shape had guiding significance for the design of similar projects. In the early stage of this paper, the parametric design command flow of ANSYS was used for secondary development. Taking Duncan Zhang classical and modified models as material constitutive models, the finite element calculation of the overall structure was carried out and the law of stress and deformation was analyzed. In the later stage, based on the actual design requirements, from the perspectives of overburden compression and shear resistance, it connected the ANSYS finite element analysis and MATLAB optimization module, and obtained the optimal dam type through optimization design and scheme evaluation, so as to reduce the material consumption (save 11 .3%·) and improve the foundation stress state (remove the shear failure point and reduce the maximum compressive stress by 9.2%) . [ABSTRACT FROM AUTHOR]

When evaluating the safety status of hydraulic steel gate in service, it is usually necessary to comprehensively consider the influence of evaluation indexes from many aspects, among which there are qualitative and quantitative indexes, which is an issue of uncertainty and fuzziness. Based on this, this paper combined the intuitionistic fuzzy hierarchy method and cloud model method to evaluate the safety state of the gate. Firstly, this paper built the evaluation structure system of hydraulic steel gate based on the idea of hierarchy method, and then invited experts to evaluate and compare the indicators on the basis of intuitionistic fuzzy theory, established the judgment matrix and comprehensively analyzed the weight of each indicator. To adopt the method of cloud model, combining with engineering example, set up the index of diagnosis of cloud, the diagnosis of synthesis of various cloud chart, finally got the diagnosis cloud gate test result and comparing with state chart, finally it was concluded that the gate security status. Comparing with the actual situation, the results of this method are accurate and intuitive. [ABSTRACT FROM AUTHOR]

Water supply system is an important system for the production and life of urban residents and the development of social ecology. However, with the increasing demand for water resources, the current urban water shortage is becoming increasingly serious. In addition, the overall construction and operation cost of urban water supply system is also increasing. In order to save water resources as much as possible and minimize the cost of water supply on the basis of ensuring the quality, pressure and water demand of various users, this paper proposed a multi-source water supply system scheme and carried out the optimal allocation of water intake, treatment capacity of water plants and distribution capacity of various users. Firstly, the structure of urban water supply system was briefly introduced; secondly, the mathematical model of multi-source water supply system optimal allocation was established, and the working process of the optimization algorithm used in the optimization process was analyzed; finally, the optimal allocation method of multi?source water supply system proposed in this paper was verified with the Zunyi tourism development zone as the research area. The results show that the proposed optimization method can achieve the optimal configuration of multi-source water supply system with less iterations. [ABSTRACT FROM AUTHOR]

In order to systematically analyze and accurately quantify the matching characteristics of water resources and economic and social development in prefecture-level cities, typical factors such as total water resources, water consumption, population, GDP and cultivated area were selected in this paper, and a new quantitative research idea that simultaneously applying the calculation methods of matching degree based on Gini coefficient and data sequence was proposed. Taking 10 prefecture-level cities along the Shaying River as examples, this paper quantitatively analyzed the spatial-temporal matching relationship between water resources and economic and social development from 2009 to2018. The results show that the application of the above two methods can comprehensively study the matching issue of the two systems elements from the perspective of the whole time/space and the single city/time. There are some differences in the temporal Gini coefficient among prefecture-level cities, but the matching degree of different elements is basically consistent and the results are all good. Except that the temporal matching degrees of total water resources and GDP, water consumption and GDP present a low-high-low evolution trend, the results of other elements present a fluctuation trend over time. The spatial Gini coefficient varies little on the time scale, while there are significant differences among different matching elements. The spatial matching degree is basically consistent in time and the results of some prefecture level cities are poor, especially in Zhengzhou, Nanyang and Zhumadian cities. [ABSTRACT FROM AUTHOR]

This paper proposed an improved method for automatic extraction of multi-band spectral relationship of narrow and deep rivers in mountains and valleys with high sediment concentration from Landsat 8 OLI images, which overcame the mixed pixel effect of mountain shad ow and exposed bedrock in the downstream section of the reservoir. Taking Jingeun to Dongzhuang Reservoir section in the middle reaches of Jinghe River on the Loess Plateau as an example, it separated the water body and mountain shadow, bare mountain and bedrock beach by considering the characteristics of the multi-band spectral, and then constructed a water body extraction model suitable for narrow and deep rivers with high sediment concentration in valleys. Compared with other water extraction models, the method proposed in this paper can over come the influence of shadow close to river channel and bedrock downstream of reservoir on water extraction, and improve the extraction accuracy of narrow and deep rivers with high sediment concentration in mountain canyon. [ABSTRACT FROM AUTHOR]

In order to realize the safe operation and long-term service of South-to-North Water Transfer Project (SNWTP), it is significant to avoid adverse effect led by abnormal state of open channel. Considering the fuzziness of evaluation index and one-sidedness of single method, the evaluation index system of open channel was established with objective analysis method. The improved extension-hierarchical analysis model was proposed to determine the subjective weights based on interval quantization in extension theory, then the subjective and objective weights were combined as fusion weight. The advantages of fuzzy comprehensive evaluation method and grey clustering evaluation method were assembled in order to build the grey-fuzzy evaluation method for open channel. Taking the open channel in the Middle Route of SNWTP as an example, the method and model established in this paper were utilized to evaluate its serviceability and the evaluation results prove their validity and feasibility, which can provide a basis for the operation and maintenance of the open channel projects in the Middle Route of SNWTP. [ABSTRACT FROM AUTHOR]

In order to explore the current characteristics of the temporal and spatial changes of water quality in the Taoge Basin, the paper analyzed the future change trend of the water environment in the basin. Taking the main inflow and outflow rivers in the Taoge Basin as the research object, according to the monitoring data of main pollutants of the Taoge Basin from 2020 to 2021 and using the methods such as comprehensive water pollution index and dynamic analysis, it comprehensively evaluated the water quality of the basin. A differential moving average autoregressive model（ARIMA） was selected to perform multi-step forecasting of the main pollution factors of water quality. The results show that the water quality of the Taoge Basin has been generally improved, and the comprehensive pollution index of the Taoge Basin in October 2021 has been decreased by 9.88% compared with that in July 2020. The concentration of total phosphorus, permanganate index and total nitrogen in the water environment of the Taoge River Basin shows a downward trend from 2020 to 2021, with a decrease of 14.57%, 9.36% and 14.78% respectively. But phosphorus is still the main factor restricting the water quality of rivers. The water system is divided based on the connection of rivers and lakes. The comprehensive pollution index of Changdang Lake-Gehu Lake and Beijing-Hangzhou Canal-Xinmeng River water system has been decreased by 7.26% and 9.99% respectively, the comprehensive pollution index of Gehu Lake-West Taihu Lake water system has been increased by13.14%. The ARIMA model can better predict the change trend of river pollutants in a long period of time in the future, which can provide technical support for the water environment management of Taoge River Basin. [ABSTRACT FROM AUTHOR]

Under the background of the country’s vigorous development of “double carbon” and the development of clean energy, hydropower projects have been significantly supported and promoted. The investment and construction of hydropower projects are inseparable from accurate value assessment. In order to improve the shortcomings of non-random uncertainty in the traditional investment decision-making method, this paper improved the B-S option pricing model based on the payment dividend and trapezoidal fuzzy number, and combined the free cash flow discount model and the real option model to construct a hydropower station project value evaluation and expansion model. The empirical analysis of small and medium-sized hydropower stations was selected as a case study, and the evaluation results were compared with the evaluation results obtained by the pure application of the net present value method and the real option pricing model to verify the feasibility of the model. The results show that the fuzzy real option method has good applicability for hydropower station projects, the payment of dividends will reduce the option value, and the volatility and option value calculated by the model are more objective and reasonable. [ABSTRACT FROM AUTHOR]

The water body in the Yellow River basin is complex. Rapid and accurate water extraction in the basin is of great significance to the ecological protection and high-quality development of the Yellow River Basin. However, the existing water body indexes can not meet the requirements of removing the inherent mountain shadow of remote sensing images and accurately extracting complex water bodies. Based on Google Earth Engine (GEE) platform and Sentinel-2 remote sensing images, this paper proposed a Yellow River Basin Water Index (YRBWI), and the effect of water extraction results were compared with the Normalized Difference Water Index (NDWI), Modified Normalized Difference Water Index (MNDWI) and Shadow Water Index (SWI). The results show that YRBWI achieves an excellent water extraction effect in the Yellow River Basin, specifically: YRBWI can solve the confusion of mountain shadows and accurately extract water bodies with high sediment content; compared with NDWI, MNDWI, and SWI, YRBWI has the largest OA and Kappa values, indicating that YRBWI has the highest water extraction accuracy; the water body extraction accuracy of YRBWI is insensitive to the change of threshold value and has high robustness. [ABSTRACT FROM AUTHOR]

In order to promote the rational allocation of water resources in Shaanxi Province and the Yellow River Basin and ensure regional water security, based on virtual water theory and inter-regional input-output table of China, this paper calculated the water consumption coefficients of three major industries virtual water volume in Shaanxi Province, and the virtual water trade volume between this province and other provinces in China in 2007, 2010, 2012, 2015 and 2017 with the help of input-output model, and explored the main factors affecting the change of virtual water volume in Shaanxi Province by using gray correlation model. Further, the inter-industry allocation characteristics of virtual water in Shaanxi Province were analyzed and the virtual water trade network between Shaanxi Province and other provinces were established. The results show that a) the coefficient of direct water consumption and complete water consumption coefficient of the primary industry in Shaanxi Province are higher than that of the secondary and tertiary industries, but all show a decreasing trend over this time, indicating that the province’s water use efficiency are constantly improving. b) The primary and secondary industries account for the majority of the virtual water supply in Shaanxi Province, and the level of agricultural technology, population size, urbanization rate, food production, industry and construction development level are the main factors affecting the virtual water supply of the primary and secondary industries in the province. c) More than 70% of the virtual water in Shaanxi Province are consumed by itself and transported to other provinces mainly are Guangdong, Shanghai, Tianjin, Hebei, Shandong, Shanxi, Inner Mongolia and Henan provinces. It mainly exports to the primary industry. More than 90% of the virtual water input derives from the secondary and tertiary industries of Jiangsu, Guangdong, Shanghai, Anhui, Zhejiang and Hunan provinces. d) Shaanxi Province has maintained net input state for a long time in the inter-provincial trade; compared with the actual water resources trade net virtual water trade between Shaanxi Province and Sichuan, Liaoning, Jilin and other provinces is unreasonable. Shaanxi Province should promote the spatial and temporal matching of virtual water and physical water by adjusting the industrial structure and optimizing the inter-provincial trade network, which is of great significance for the rational use of water resources at the Yellow River Basin scale and even at the national scale. [ABSTRACT FROM AUTHOR]

In order to improve the effectiveness of interprovincial ecological protection and control in the Yellow River Basin, this paper used evolutionary game model to study the dynamic evolution process of government collaborative management in the upper and lower reaches of the river basin, and analyzed the factors affecting the main body’s strategy selection. The applicability of the model in the Yellow River Basin (Henan-Shandong Section) was evaluated by empirical analysis based on cost-sharing model combined with the “Ecological Compensation Agreement” (hereinafter referred to as “Compensation Agreement”) signed by Henan and Shandong provinces. The results show that a) the stability of the evolutionary game model has nothing to do with the benefits of ecological protection and the ratio of rewards and punishments in the downstream region. The core of upstream and downstream governments’ participation in ecological protection and control lies in whether the maximum reward amount of the government is enough to cover the governance cost. b) When the government’s incentive and constraint amount is more than twice the upstream ecological protection cost, it is more conducive to achieve the overall optimal decision. c) Taking Henan and Shandong provinces as examples, the ecological protection cost and compensation amount of the river basin are calculated. According to the Compensation Agreement, the current compensation amount is relatively small for the importance of the ecological protection of the two provinces and the Yellow River. Based on this, suggestions are put forward to increase the award and punishment, explore diversified compensation methods and promote the sustainable development of ecological compensation. [ABSTRACT FROM AUTHOR]

In order to study and discuss the influence of groundwater on each channel section of the Jiaodong Water Diversion Project, this paper used the Analytic Hierarchy Process coupled with Criteria Importance though Intercrieria Correlation (CRITIC) to calculate the weight, based on the variable fuzzy theory, combined with the water quality sampling data and engineering data along the Jiaodong Water Diversion Project, and comprehensively considering the actual conditions, chose the two subsystems of effects of engineering corrosion and effects of engineering form, including seven index values, to construct the impact evaluation system of groundwater on the Jiaodong Water Diversion Project, and analyzed the open and closed channels including nine channel sections. The results show that the average comprehensive score of each channel section is 1.748, in which the comprehensive score of the open canal section is higher (the highest is 2.308 in the section of Pingdu) and the score of culvert section is lower (the lowest is 1.411 in the section of Laishan), indicating that the groundwater has a greater impact on the open channel and a lesser impact on the closed channels. In general, groundwater has weak influence on each channel section of Jiaodong Water Diversion Project. [ABSTRACT FROM AUTHOR]

It is necessary to accurately monitor the scope of land inundated by rainstorm and flood disasters in a short time and evaluate the disaster situation. In this paper, the flood range of “July 20” rainstorm flood disaster in northern Henan was extracted by SAR image. Combined with the land use classification data before flood, the disaster situation of the land inundated by the rainstorm and flood disaster in northern Henan was evaluated by using the system collaborative superposition analysis method. The total area of water body before flood in northern Henan is 9.16 km² and the area of water body after flood is 268.91 km², increasing 259.75 km². Among them, Junxian County, Weihui City and Qixian County are closer to the Taihang Mountains and located at the intersection of Weihe River, Qihe River and Communist Canal. The low-lying area is the main flood detention area. Therefore, the flood inundation range in this area is the largest and the three counties (city) are most seriously affected. The areas inundated by rainstorm and flood are mainly rural areas. The land use types are cultivated land and construction land, accounting for 81.57% and 17.23% of the total affected area respectively. Extracting the flood water body range from SAR image can quickly and effectively monitor the flood inundated area. Combined with land use classification data, it can accurately evaluate the rainstorm and flood disaster, and provide scientific data support and reference for reducing post disaster risk, preventing adverse effects and post disaster reconstruction. [ABSTRACT FROM AUTHOR]

Planning of guide lines of river regulation is an important evidence for river conservation and regulation as well as water front function maintenance and management. Studying the flood control guide lines of river regulation is of great significance to protect river ecosystem and settle water rights scientifically and rationally. In this paper, thelayout principles of guide lines of river regulation in Qingzhang River were examined and proved. Several guide lines of river regulation width control parameters such as flow per unit width, flow velocity and water level rising value were proposed. Taking the Qingzhang River as an example for further research, the layout principle of the flood control guide lines of river regulation was refined, and the specific control parameters of the flood control guide lines of river regulation were put forward based on the analysis and calculation of the hydrological data of the Qingzhang River, and the application analysis of the results was carried out. The results show that the proposed layout principles and control parameters of flood control guide lines of river regulation are suitable for Qingzhang River, and the flood control guide lines laid out of river regulation in this way are reasonable. [ABSTRACT FROM AUTHOR]

Happy River is the new guidance and requirement of river management in the new period of China. In order to provide reference for the measurement and evaluation system of happy river, this paper analyzed the connotation of happy river, summarized the existing methods of river evaluation, and conducted the bibliometric analysis of the research literature. The results show that, the current research in this field is basically based on the concept of river health and human-water harmony. Most of the research is still from the perspective of rivers, and there is a lack of discussion on the mechanism of happiness. The future research direction of happy river evaluation method is put forward: to explore the connotation of happy river and its influencing factors; to study the selection of evaluation index and the construction of evaluation system; and to carry out practical application based on the established evaluation system in the specific watershed, therefore to verify its reliability. [ABSTRACT FROM AUTHOR]

In order to promote low-carbon transition and high-quality development process of agriculture in the Yellow River Basin, this paper used coefficient method to calculate the agricultural carbon effect of nine provinces（regions） in the Yellow River Basin from 2000 to 2020 and analyzed its spatial-temporal evolution law. The fairness and difference of provincial agricultural carbon emissions in the Yellow River Basin were researched from the perspectives of ecological carrying capacity and economic contribution capacity. The results show that the overall agricultural carbon effect of the Yellow River Basin maintains a stable growth trend, with the maximum increase in Inner Mongolia and the minimum increase in Sichuan. The agricultural carbon effect of each province (region) shows the characteristic of net carbon sink. The agricultural carbon effect of the Yellow River Basin shows the unbalanced spatial distribution of “high in the eastern area and low in the western area, high in the upstream and low in the downstream.” Based on the numerical difference of ecological carrying coefficient and economic contribution coefficient in the fairness evaluation model of agricultural carbon emissions, the nine provinces (regions) in the Yellow River Basin are divided into four categories of double-advantage type, ecological dominant type, economic dominant type and double-disadvantage type. Among which, Shandong has always been the double-advantage type; Henan has always been the ecological dominant type; Sichuan and Qinghai have always been the economic dominant type; Inner Mongolia has transformed from the double-advantage type into the ecological dominant type; Shaanxi and Shanxi have changed from the ecological dominant type to the economic dominant type and the double-disadvantage type respectively; Ningxia and Gansu have always been the double-disadvantage type. [ABSTRACT FROM AUTHOR]

Dredged soil is a kind of material with complex properties and uneven distribution. In order to study the compression characteristics of dredged soil containing organic matter and the corresponding improvement scheme, this paper investigated the engineering indicators of natural dredged soil with 0%-11% organic matter content by experiments. The micro-structure and mineral composition of dredged soil were analyzed by scanning electron microscopy（SEM） and X-ray fluorescence spectroscopy（XRF）. The compression characteristics of improved soil by adding lime, fly ash and volcanic ash were analyzed by one-dimensional consolidation test, and the influence of OMC to the improvement effect was discussed. The study results show that with the increase of OMC, the water content limit of natural dredged soil increases, combined with the density decreasing and the alkalinity decreasing from medium alkalinity to slightly alkalinity. The compression index of natural dredged soil ranges from 0.10 to 0.32. With the increase of organic matter content, the compressibility and expansibility become higher. Both lime and fly ash can effectively improve the anti-compression ability of dredged soil while fly ash has obvious improvement effect on dredged soil with various organic matter contents. When the content of fly ash exceeds 15%, compressibility can be greatly reduced. The volume compression coefficient and compression index increase after the addition of volcanic ash, indicating adverse effects of anti-compression ability. The study can provide reference for the utilization of dredged soil in water transportation projects for building materials. [ABSTRACT FROM AUTHOR]

Border irrigation is the most widely used irrigation method in north China. Optimizing border irrigation technical parameters is an important measure to improve the irrigation and fertilization performance and reduce agricultural non-point source pollution. The multiple technical parameters of border irrigation and the spatial variability of soil infiltration and solute transport parameters make it difficult to study the fertilization performance of border irrigation. This paper collated the commonly used evaluation indexes of irrigation and fertilization performance, summarized the research progress of border irrigation technology factors such as soil texture, fertilization mode, fertilization opportunity and water improvement percentage on the impact of irrigation and fertilization performance, and the appropriate threshold of related parameters, described the application of surface solute transport model suitable for border irrigation and fertilization in different scenes, and summarized the combination of border irrigation technology parameters with high irrigation and fertilization performance. Based on the previous research, the potential research directions in the future were prospected in order to provide valuable reference for further improving crop yield and reducing the impact of fertilizer use on the environment. [ABSTRACT FROM AUTHOR]

Sustainable supplier selection is very important for the sustainable development of water environment treatment PPP project. On the basis of considering the sustainability of suppliers, this paper built a sustainable supplier selection index system from five aspects of financial status, technical strength, management ability, reputation and technical solutions. On this basis, the sustainable supplier decision-making model of water environment treatment PPP project based on probability hesitation fuzzy and Multiplicative and Multi-Objective Ratio Analysisl（MULTIMOORA） method was established. In order to overcome the difference of experts′ cognition, Shapley value method was introduced to modify the index weight determined by AHP. In order to preserve the integrity of decision information to the greatest extent and reduce the complexity of decision model, probability hesitation fuzzy Maclaurin symmetric mean operator（PHFMSM operator） was introduced to integrate decision information. Taking the sustainable supplier selection of a water environment treatment PPP project as an example, the validation of the model showed that it was reasonable to consider the supplier′s own sustainability in the decision-making process, which could improve the reliability of the decision results. [ABSTRACT FROM AUTHOR]

Urban water demand prediction is an important basis for urban water resources planning, management and decision-making. In order to improve the accuracy of water demand prediction, a nonlinear prediction model based on least squares support vector machine（LSSVM） was proposed. Aiming at the issue that the optimization process of Grey Wolf Optimization Algorithm（GWO） was easy to fall into local optimization, general opposition-based learning and nonlinear control parameters were used to improve the global optimization performance. The improved GWO algorithm was more suitable for the fitting of nonlinear model parameters. Therefore, IGWO was introduced into LSSVM water demand prediction model to fit the super parameters of the model. The model was tested by using the urban water supply data of Shanghai in recent years. The simulation results show that the average relative error of the urban water demand prediction model proposed in this paper is 0.78%, and the maximum relative error is 1.37%. It has good generalization ability and can be used as an effective method of water demand prediction. [ABSTRACT FROM AUTHOR]

Exploring the beach land function change and its driving factors in the lower reaches of the Yellow River is one of the important ways to promote the optimization and sustainable development of land function in the study area. Based on the land use remote sensing data from 1980 to 2020, this paper analyzed the temporal and spatial variation characteristics of various types of land functional land in the study area, and used geographical detectors to study the influence intensity and interaction mechanism of various factors on the land function change of the river beach and water area in the lower reaches of the Yellow River. The results show that a) the economic and water-sediment functional land covers the largest area and has the widest distribution range. The former is distributed along the river channel, and the area shows a trend of “sharp decrease-slow increase-stable”; the latter is along the river channel. b) Soil type and population spatial distribution are important driving factors affecting land function change in the study area. The spatial-temporal differentiation exhibits two-factor enhancement and nonlinear enhancement. [ABSTRACT FROM AUTHOR]

In order to comprehensively evaluate the ecological sustainable development capacity of water-energy-food system in the Yellow River Basin, based on the energy theory and method, and combining with the entropy method, this paper built an evaluation index system for the ecological sustainable development capacity of the water-energy-food system in the Yellow River Basin, and comprehensively evaluated the ecological sustainable development capacity of this system from 2008 to 2018. The results show that a) from the overall perspective of the Yellow River Basin, the nexus system belongs to the resource-consuming economic development mode from 2008 to 2018. The rapid economic development has exerted great pressure on the local ecological environment, and the system has been in a state of high environmental load for a long time, resulting in the continuous weakening of the ecological sustainability of the system. b) From the perspective of provinces in the Yellow River Basin, the ecological environment pressure of the lower reaches of the river basin is increasing day by day and the ecological sustainable development capacity is poor. Therefore, the exploitation of renewable resources should be strengthened and the dependence on non-renewable resources should be reduced. The upstream provinces have relatively less environmental pressure and better ecological sustainability. It should strengthen infrastructure construction and promote economic development. c) The overall structural equilibrium of water-energy-food in the Yellow River Basin provinces and regions shows significant variability in time and space, and the ecological sustainability of the system is weakening. [ABSTRACT FROM AUTHOR]

The previous studies on flood evolution in floodplains followed the analysis method of channel flood evolution, which failed to fully reflect the characteristics of floodplain evolution in floodplains. Taking the Changyuan beach in the lower reaches of the Yellow River as an example, this paper proposed a two-line flood evolution diagram of flood flow and direction changing with time in the floodplain. According to the characteristics of flood water volume, the flood evolution characteristics of the floodplain were divided into four types: complete flood discharge, stable flood storage, increasing flood storage, and peak storage and stagnation. According to the flood direction characteristics, the flood evolution characteristics of the floodplain were divided into four types: monostable independent type, single-variable independent type, double-variable independent type, and double-variable cross type. It could more intuitively reflect the distribution characteristics of flood inflow and outflow water volume and direction at different locations in the floodplain. By analyzing the three characteristic values of concentration, consistency and turning angle, the process of flood in the floodplain from dispersion to concentration and then to dispersal under different inundation time and topographical conditions in Changyuan floodplain was analyzed, in order to lay a foundation for the determination of flood inundation information in the floodplain in the future. [ABSTRACT FROM AUTHOR]

The ice flood of the Yellow River is characterized by short prediction period, difficult information acquisition, difficult prevention and control, and wide disaster range. Therefore, it is need to carry out research on the problems related to the ice flood of the Yellow River. Based on the basic theories and research methods of hydrology, thermodynamics, river bed evolution, statistics, water kinematics, blasting and so on, this paper summarized the basic laws of ice evolution, integrated ice monitoring technology, ice forecasting technology, reservoir ice control and regulation technology, and ice breaking technology, etc. The relevant achievements have basically solved many difficult problems that seriously affect the ice disaster prevention and mitigation in the Yellow River, such as the difficulty in obtaining the ice situation information, the lack in grasping the ice situation information, the low accuracy of the ice situation prediction, the rapid formation of the ice jam and ice dam, the low efficiency in breaking the ice jam, and the poor experience of the ice control dispatching. [ABSTRACT FROM AUTHOR]

Although self-accelerating turbidity current has been demonstrated in theory, it is only occasionally observed at the estuary of some large rivers due to the difficulty in obtaining field currents data. This paper set up a water and sediment density current experimental flume, where the decelerating currents and self-accelerating currents had been achieved under different conditions. Based on this experimental results, adjoined water and sediment characteristics have revealed at current head evolution, thereafter, the experimental results verify the theoretical critical conditions for the occurrence of self-accelerating turbidity current. [ABSTRACT FROM AUTHOR]

Continuous sharp bends exist widely in natural rivers. Studying the law of water and sediment movement has important guiding significance for the regulation and disaster prevention of sharp bends. Based on the movable bed physical model test of unsteady flow bed, this paper discussed the cumulative effect of continuous sharp bends on sediment transport capacity of the lower Yellow River reach. The results show that the continuous sharp bends cause additional energy loss, which leads to the overall deposition of the river channel under specific water and sediment conditions. The sediment transport capacity of the continuous sharp bend sections declines along the river and presents a characteristic of the greater the discharge, the greater the reduction of sediment transport capacity. The horizontal geometric characteristics of sharp bends can be expressed by the product of the ratio of center angle and curvature radius to river width. In the flood stage, the cumulative effect of continuous bends on sediment transport capacity is that the horizontal geometric characteristics of sharp bends are negatively correlated with sediment transport capacity. In the recession stage, when the floodplain discharge is close to the bankfull discharge, the sediment transport capacity slightly recovers in local bends, and after the flow returns to the channel, the horizontal geometric characteristics of the bends and the sediment transport capacity return to a negative correlation again. [ABSTRACT FROM AUTHOR]

Alleviating the contradiction between economic development and energy conservation and emission reduction is an urgent issue to be solved in resources-based cities in the Yellow River Basin. In order to discuss the influencing factors of carbon emissions of resources-based cities in the Yellow River Basin and make the peak prediction of carbon emission, this paper selected the data of resources-based cities in the Yellow River Basin from 2000 to 2020, used the extended STIRPAT model to analyze the influencing factors of carbon emissions and built a carbon emission prediction model based on BP neural network to analyze the carbon emission trends under different scenarios. The results show that: from 2000 to 2020, the carbon emissions of resources-based cities in the Yellow River Basin show a fluctuating upward trend; population size, per capita GDP, urbanization rate and energy consumption per unit of GDP can promote the increase in carbon emissions, while industrial structure has a inhibitory impact on carbon emissions; the carbon emissions of resources-based cities have bigger differences under different scenarios. Based on this, it is proposed that the resources-based cities in the Yellow River Basin should promote the speed of urban transformation, accelerate the optimization of industrial structure, vigorously develop clean energy, optimize the energy consumption structure, encourage energy conservation technology innovation and improve energy utilization efficiency. [ABSTRACT FROM AUTHOR]

The construction of high-standard warping dam is one of the main measures to achieve the national strategic goals of ecological protection and high-quality development of the Yellow River Basin, which will play a greater role in promoting the high-quality development of water and soil conservation and regional economic and social development. Based on the goals and requirements of high-quality warping dam construction, this paper analyzed the historical process of warping dam construction and technical standard development in the Yellow River Basin, discussed the definition and connotation of high-standard warping dam, put forward scientific issues and key technologies that need to be studied, and looked forward to the development prospect of high-standard warping dam. The warping dam in the Yellow River Basin has gone through a development process of more than 450 years in six stages, and the high-standard warping dam marks that the construction of warping dam has entered into a new period from “quantity”development changed to “quality”promotisn. The technical standards of warping dams have undergone a development process from the formation in the mid-80s of the 20th century to continuous improvement and revision along with the level of science and technology and practical experience in different periods. Compared with ordinary warping dams, high-standard warping dams have special essential characteristics, value and richer connotation and extension. The status and driving mechanism of high-standard warping dams in the comprehensive benefit chain and the technical standards of high-standard warping dam construction are topics that need to be studied in the future. The construction of high-standard warping dams will surely promote the high-quality development of soil and water conservation, and play a greater role in the coordinated development of multiple elements such as regional ecological governance, derivative economy, social culture, and landscape pattern. [ABSTRACT FROM AUTHOR]

With the large-scale integration of new energy into the grid, there is an urgent demand for peak-shaving resources in the power system, and it is urgent to comprehensively improve the utilization level of flexible power sources in the power system to maintain the safe and stable operation of the power grid and improve the efficient of clean energy consumption. As a regional power grid with the highest proportion of new energy grid-connected in China, the Northwest Power Grid is affected by the factors of few newly installed coal power plants in recent years, the pumped storage power plant has not been put into operation on large scale, and the scale of electrochemical energy storage is insufficient. In a word, the insufficient flexible resources restrict the efficient use of new energy. In this paper, by exploiting the role of cascade reservoirs that have been put into operation on Upper Yellow River, and further excavating the peak regulation potential of cascade hydropower stations, it can achieve the effectiveness that is similar to energy storage and effectively save the construction cost of peak regulation resources. By establishing a comparison model, three scenarios of cascade hydropower not participating in peak shaving, direct hydropower participating in peak shaving, and cascade hydropower participating in peak shaving were analyzed, and the positive contribution to the grid peak shaving resources under the mode of participating in peak shaving was verified. [ABSTRACT FROM AUTHOR]

At present, it is difficult to evaluate the feasibility of the current reservoir dam emergency plan and lack of technical guidance in the evaluation process. From the four dimensions of organization system, operation mechanism, emergency support and emergency training, this paper established the secondary feasibility evaluation index system of reservoir and dam emergency plan. It used analytic hierarchy process and entropy weight method to calculate the principal and objective solid weight of each index and introduced genetic algorithm and variable weight theory to make coupling correction. Combined with cloud model theory, a comprehensive evaluation model for the feasibility of reservoir dam emergency plan was established. The results show that the comprehensive score of the feasibility of the reservoir emergency plan is 85.66, and the evaluation grade is excellent, which is consistent with the evaluation result of the plan. The validity and applicability of the improved method in the feasibility evaluation of reservoir dam emergency plan are verified. [ABSTRACT FROM AUTHOR]

Different types of machine learning models have great differences in the prediction of groundwater arsenic. The existing machine learning models cannot simulate the spatial variation characteristics of groundwater arsenic pollution well. Based on 1081 measurements of arsenic concentration in shallow groundwater in northern Henan region of the Lower Yellow River, combined with human activities, climate, sedimentary environment, soil physical and chemical characteristics, hydrogeology and other environmental factors, this paper constructed a stacking integrated model with RF, XGBoost, SVM as the base learners and LDA as the meta learner to predict the spatial distribution of high arsenic groundwater in the study area, and identified the key environmental variables. The results show that arsenic concentration in groundwater in the study area ranges from 0.01 to 190 μg/L, and the excess rate is 16.74%. Comparing with RF, XGBoost and SVM, the Stacking integrated model has the maximum AUC, Accuracy, Specificity and Recall. The groundwater with high arsenic content is mainly distributed in the Taihang piedmont depression and the Yellow River rupture fan area, accounting for 33.81% of the total area. The Yellow River breach, the annual average temperature, annual precipitation, elevation and hydraulic gradient are the important environmental variables affecting the groundwater with high arsenic content in the study area. The comprehensive analysis shows that the sedimentary environment is significantly correlated with the arsenic enrichment in the groundwater. [ABSTRACT FROM AUTHOR]

In view of various problems faced by China’s levee project management and on the basis of sorting out and analyzing the experience of standardization management in pilot areas, this paper expounded the connotation of levee engineering standardization management. The five-element structure model was composed of five dimensions: project status, safety management, operation management and protection, management guarantee and information construction, and the key factors of dike management were analyzed. Based on the analytic hierarchy process, taking engineering safety as the bottom line and improving capacity as the goal, the standardized management evaluation system of levee engineering was preliminarily built. [ABSTRACT FROM AUTHOR]

Social value assessment is an effective means to comprehensively reflect the value of PPP project in urban water environment treatment. In this paper, the social value assessment model based on social return on investment (SROI) was constructed for the connotation of social value and project characteristics, based on the logic model of change theory and the content of PPP project in urban water environment treatment, identifying key information such as stakeholders, project inputs and project outcomes. Based on the stakeholder theory, SROI was used to monetize the economic, environmental and social outcomes and the inputs of PPP project, and then comprehensively assessed the social value of the project. Case studies show that the social value assessment framework is feasible and the social value created by the project is much higher than that of the project inputs, with good outcome benefits. [ABSTRACT FROM AUTHOR]

In order to further optimize the urban water-saving evaluation system and provide effective reference for the establishment of regional water-saving evaluation system and the prediction of water-saving potential, this paper analyzed the temporal and spatial evolution trend of urban water use and water saving in six provinces (cities), including Beijing, Tianjin, Shandong, Shanxi, Hebei and Henan province from 2006 to 2018, and adopted the maximum mutual information coefficient algorithm to evaluate the mutual correlations between each urban water use indicator, excavated the deep relationship between these indicators, and identified the key drivers of water saving development. The results show that total water consumption in the study area shows an increasing trend, and the water structure is changing from production and operation water to household water. The proportion of household water consumption is increasing, while the proportion of production and operation water consumption is decreasing. The amount of water saving is mainly contributed by industrial water saving during the studied range, while the importance of domestic water saving is gradually enhanced. The correlation between regional population size, economic development level and water saving is stronger than the correlation between per capita water resources and water saving. Compared with technological progress, the improvement of the comprehensive efficiency of industrial water use brought about by the adjustment of the industrial structure has a more significant effect on promoting industrial water saving. The urban water supply system and wastewater treatment system are highly compatible with the economic scale, but the leakage loss rate of water supply network and the utilization level of reclaimed water are not compatible with the current development stage. There still has space for promotion in the leakage loss control of urban water supply networks and the replacement of unconventional water sources. [ABSTRACT FROM AUTHOR]

Since the operation of Xiaolangdi Reservoir, great social and economic benefits have been brought into play in ensuring the flood control and silt reduction, the safety of living, production, irrigation and ecological water use. Based on the measured data, this paper analyzed the outflow conditions of high water level density flow and the influence factors of sediment discharge of Xiaolangdi Reservoir. The results show that during the high water level operation (above 235 m) of Xiaolangdi Reservoir, two conditions shall be met for the density flow to reach the front of the dam. a) The inflow flood process shall not be less than 3 days and the fine sediment content shall be higher than 40%. b) Inflow discharge Qi shall not be less than 4000 m³/s. And meet the sediment concentration shall not be less than 13.0 kg/m³. Alternatively, if inflow discharge Qi is between 1700 m³/s and 4000 m³/s, and meet the sediment concentration Si shall not be less than 86 minus 0.018Qi. Sediment discharge ratio of reservoir η is inversely proportional to the ratio of the water storage body and the outflow discharge and the ratio of the inflow and outflow discharge. The larger the maximum continuous 3-day inflow sediment transport rate, the stronger the flow power and the better the sediment discharge effect. The research results can provide a certain technical support for the high water level density flow sediment discharge operation of Xiaolangdi Reservoir. [ABSTRACT FROM AUTHOR]

Affected by the rare autumn rain in West China, severe autumn floods occurred in the middle and lower reaches of the Yellow River in 2021. In the face of the flood situation, in accordance with the principle of “system, overall planning, science and safety”, with the concept of comprehensively balancing flood storage and release space and reasonable sharing of flood risk as the dispatching concept, through the fine dispatching water project, Huayuankou twice more than 10000 m³/s flood had been reduced to about 4800 m³/s, successfully fighting the autumn flood. During the autumn flood season, there were no major dangers, major disasters or casualties, ensuring the safe flow of flood waters into the sea, preventing the displacement of 1.4 million people and the inundation of 266 thousand hectares of farmland in the downstream flood-plain, and ensuring the safety of people’s lives and property in the downstream flood-plain. This paper briefly introduced the situation of autumn flood control in 2021, summarized the concept of this flood control, and put forward the understanding of doing a good job in autumn flood control and prevention. [ABSTRACT FROM AUTHOR]

Under the changing environment, the study puts forward the sediment disposal scheme that can maintain the stability of the lower reaches of the Yellow River and the floodplain to meet the requirements of the new situation, which plays an important guiding role in the control of the lower reaches of the Yellow River and even the watershed. Through the analysis of measured data and mathematical models, this paper analyzed the temporal and spatial distribution changes of sediment entering into the Yellow River. It is considered that after the completion of Sanmenxia Reservoir, the sediment discharge into the sea during the three reservoir operation stages is dominant, but after the completion of Xiaolangdi Reservoir, the sediment retaining in reservoir is dominant. Large reservoirs are important factors affecting the spatial distribution of sediment and the scouring and silting of the river channel. Under the scenario of 800 million to 300 million tons of incoming sediment of the Yellow River, the lower reaches of the Yellow River cannot achieve the stability of the river channel and the floodplain. Five sediment disposal schemes have been proposed. Through calculation, analysis and evaluation, the optimal scheme has been obtained, that is, Guxian and Taohuayu reservoirs plus floodplain ecological management scheme. The construction of Guxian Reservoir can basically realize that the riverbed of the lower reaches of the Yellow River will not be silted up for 50 years, and the floodplain ecological management can eliminate the secondary suspended river, in addition, the Taohuayu Reservoir can significantly improve the flood control standard for floodplain, so the comprehensive evaluation of the scheme is the best. [ABSTRACT FROM AUTHOR]

The realization of the “Double Carbon Goal” needs to be supported by scientific and technological innovation, and at the same time, it will also promote the continuous progress of scientific and technological innovation. In order to explore the interaction between scientific and technological innovation and low-carbon economy in the Yellow River Basin and its influencing factors, this paper analyzed the obstacle factors in the coupling and coordination of scientific and technological innovation and low-carbon economy in the Yellow River Basin based on the coupling coordination degree model and the obstacle factor diagnostic model. The results show that the overall level of technological innovation and low-carbon economy in the Yellow River Basin has shown a steady upward trend, and there is a large gap in the level of technological innovation development between provinces. The level of coupling and coordination between the two systems is increasing year by year, and the degree of coupling and coordination between the downstream provinces and regions is better than that of the upper and middle regions. The order of the first-level obstacles for the coordination and coordination of technological innovation and low-carbon economy in the Yellow River Basin is: innovation output, green technology, innovation input, social foundation, and ecological environment. However, due to differences in location conditions and development status, the key obstacle factors in each province are different. [ABSTRACT FROM AUTHOR]

Inspection and testing is an important part of national quality infrastructure and plays an important basic supporting role in the high-quality development of water conservancy. In order to better play the important role of inspection and testing in serving the high-quality development of water conservancy, this paper studied the current situation of inspection and testing in water conservancy industry, analyzed the contents of inspection and testing served the high-quality development of water conservancy industry from the four aspects of inspection and testing served the sustainable development of environment, the quality improvement of water conservancy projects, the quality improvement of water conservancy products and equipment and inspection and testing standards supported the development of inspection and testing industry. This paper put forward the problems existing in the inspection and testing of water conservancy industry and some suggestions from the four aspects of optimizing the layout of inspection and testing market, improving the level of inspection and testing technology, strengthening the construction of integrity system and strengthening the construction of inspection and testing information platform. [ABSTRACT FROM AUTHOR]

The improvement of saline-alkali soil should be adapted to local conditions by combining protection and utilization. The Yellow River irrigation area in Binzhou, Shandong Province is rich in land resources, but the salinization is serious and the available water resources are few, which have seriously restricted the construction of Beihai economic development zone. Combined with the local actual situation, this paper discussed the feasibility of improving saline-alkali land in Beihai New District by using sediment deposited in the Yellow River irrigation area. According to the existing water system, water source, sediment source and other data, the paper demonstrated the utilization potential of water and sediment resources of the Yellow River, and proposed the layout scheme of the implementation of Xiaokaihe and Bojili joint pipeline sediment transport project and the pipeline sediment transport project of diverting water from the Yellow River to Qingdao. [ABSTRACT FROM AUTHOR]

The quality inspection and assessment is an important part ofa project construction. Traditional construction quality inspection and assessment mainly use manual paper documents for inspection, filling, signing, circulation and archiving. The data is difficult to count in real time and there are problems such as large workload, low efficiency and inconvenient query. The digital technology of engineering quality inspection and assessment was studied by this paper. Through the analysis and research based on standardize workflow, form electronization, BIM lightweight and data fusion and other related information technology methods, it designed a digital evaluation and inspection platform for engineering quality inspection and evaluation. Combining with mobile terminals, it had achieved real-time reporting, circulation and sharing of review data, on-site pictures, videos and other materials, making the review more convenient and efficient, improving work efficiency, realizing the digital and intelligent quality review and improving the quality of engineering works. [ABSTRACT FROM AUTHOR]

Funding scheme research is an important basis for the relevant department’s investment decision of Huangzangsi Dam Project. It is the comprehensive development and utilization project as the main task of ecological water distribution, which belongs to social welfare projects. Based on the benefit analysis of Huangzangsi Dam Project, the paper used different methods to share the cost, calculated the irrigation water price and engineering tariff and analyzed the tolerance capacity of irrigation water price. On this basis, the paper calculated the loan capability of the project. Considering the lending capacity of the project, the tolerance ability of irrigation water price and the possible engineering tariff scheme, the paper recommend the funding scheme and made financial evaluation for project decision-making reference. [ABSTRACT FROM AUTHOR]

The Xiaolangdi Reservoir has been mainly used for sediment trapping and water-sediment regulating in order to reduce sedimentation of the lower Yellow River after operation, which results in lower sediment transport efficiency. At present, a suitable river channel scale of median water with the bankfull discharge capacity of 4 000 m³/s has been formed in the lower Yellow River. Under this riverbed condition, how to maintain the river channel of median water of the lower Yellow River and give full play to the river sediment transport capacity becomes new requirement to the operation of the reservoir. This paper analyzed the sediment transport efficiency at different sediment concentration levels and discharge levels based on the measured data of 306 non-overbank floods in the lower reaches of the Yellow River from 1960 to 2016 and proposed that the downstream river channel had a higher sediment transport efficiency when the large flow with sediment concentration greater than 60 kg/m³, but it was also prone to cause sedimentation in the river channel. The paper further proposed the sediment transport requirement to the operation of the reservoir based on maintaining the river channel of median water of the lower Yellow River. In order to improve the sediment transport capacity of the downstream river, when the bankfull discharge capacity of the downstream river channel was about 4 000 m³/s, the Xiaolangdi Reservoir could discharge large-flow processes with sediment concentration less than 100 kg/m³. When the bankfull discharge capacity of the downstream river channel was greater than 4 500 m³/s, the Xiaolangdi Reservoir could discharge large-flow processes with sediment concentration less than 200 kg/m³. When the bankfull discharge capacity of the downstream river channel was less than 4 000 m³/s in the future, the Xiaolangdi Reservoir would still mainly trap sediment to reinvent the river channel. The calculation results of the mathematical model show that the adjustment of the operation mode of the reservoir can improve the sediment transport capacity of the downstream river, alleviate the sedimentation of the reservoir and the downstream river and maintain the river channel of median water with the bankfull discharge capacity of 4 000 m³/s for a longer period of time. [ABSTRACT FROM AUTHOR]

The changes of water and sediment in the Yellow River, especially judging the trend of the amount of incoming sediment is an important basis for determining the strategy for controlling the Yellow River. The runoff and sediment of the Jialu River Basin in the middle reaches of the Yellow River have been decreased sharply in recent years. Taking the Jialu River Basin as the research object, the paper analyzed the possible amount of incoming sand in extreme rainstorm conditions. The result shows that based on 204 rainfall events in the Jialu River Basin from 1962 to 2017, the flood rainfall-sedimentary double cumulative curve plotted on the measured data points of sediment transport shows significant inflection points in 1972 and 2002. After the inflection point, the amount of sediment transport is significantly reduced under the same rainfall conditions. Then this paper took 1971 as the natural period and 2002 and later as the current stage. The relationship between rainfall over 50mm and sediment yield was analyzed by sub-rainfall fitting method, rainfall erosion method, sub-rainfall time-segment rainfall fitting method and outsourcing line method. The fitting effect was ideal. The amJysis of rainfall by period fitting shows that, during the rainfall, the maximum 1h rainfall, the maximum 2h rainfall minus the maximum 1h rainfall, the maximum 3h rainfall minus the maximum 2h rainfall, the three sub-period rainfalls have a greater impact on the amount of sediment transported by the sub flood. Adopting 4 fitting formulas and extreme torrential rain set by historical measured extreme rainfall combined method, the current calculation of the possible amount of sediment in the Jialu River is between 12 million and 22 million tons. Compared with the natural period, the benefit of sand reduction is 88.7%-94.8%. The maximum possible sediment load of 22 million tons is 42.3% of the measured maximum subsurface flood discharge of 52 million tons. [ABSTRACT FROM AUTHOR]

To address insufficient of high spatial resolution and multi-temporal remote sensing image fusion in crop classification, a spatial-temporal image fusion method was presented for crop identification of irrigation area. In this paper, taking Hetao irrigation area as an example, the phenology differences of different crops were analyzed, combining its performance in normalized difference vegetation index（NDVI） time-series data of Sentinel 2. Then three temporal images with large differences in crop phenology were selected to fuse with 2 m spatial resolution panchromatic images by using Gram-Schmidt image fusion method. The fused high spatial resolution NDVI images were stacked to generate spatial-temporal fusion images. Based on image segmentation of spatial-temporal fusion images, cropland types were extracted by using decision tree classification. The proposed method of crop planting structure extraction obtained high accuracy with an overall accuracy of 94.8% and a Kappa coefficient of 0.921. [ABSTRACT FROM AUTHOR]

The existing two-dimensional prediction method of reservoir bank collapse has the problems with the characteristics of large amount of calculation and low accuracy. Especially in the large undulating or large curvature area of the reservoir bank, the bank collapse factors are superimposed, and the prediction accuracy is poor. In order to effectively solve the above problems, the paper used CATIA 3 D modeling platform and selected the Two Section Method that reflected the weak wave action to slice the underwater bank slope, establish a 3 D graphic model of the reservoir bank collapse and predict the bank collapse line and collapse volume with high precision. According to the research results and compared with the two-dimensional method, the model can quickly and accurately calculate the bank collapse width and volume. Especially when the topography of the reservoir bank has larger undulations and multi-sided waterfronts, this method has more prominent advantages in the prediction of bank collapse and provided a new idea for the study of reservoir bank collapse prediction. [ABSTRACT FROM AUTHOR]