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Using cooling pipes is a main temperature control measure for mass concrete dams during construction, the influence of the layout of cooling pipesto the internal temperature and stress of concrete is significant. In this paper, Xiajiang gravity dam was taken as an example, the ANSYS finite element model was used to analyze the influence of different layout of cooling pipes to the internal temperature and stress of concrete during the construction period of mass concrete. The results show that the way of encrypted water pipes layout can effectively improve the cooling effect of concrete, hut if the pipe spacing is too small, it will lead to greater tensile stress on the surface of concrete, resulting in cracks on the surface of concrete. [ABSTRACT FROM AUTHOR]

Victoria is the earliest state to establish water rights system in Australia, in which water markets have been fully developed in last three decades. China is currently in the period of deepening its reform of water rights, the advanced Victorian experiences could provide significant guidance for water rights reform and water markets growth in China, which ultimately allows markets to play a critical role in water resources reallocation. This paper analyzed the water rights system in Victoria from the aspects of water legal system, water administration, water rights allocation and types, as well as water registration and water markets, and put forward recommendations for China’s water rights reform. The results show that, in order to enhance the sustainability of water use and socioeconomic development, China should further promote research on water trading laws and regulations, establish water property rights, use water price leverage to stimulate market vitality, and rearrange the functions between government and market. [ABSTRACT FROM AUTHOR]

Agricultural efficient water saving technology develops very fast in Xinjiang, hut as the main water supply source, the fact that sediment concentration of surface water is high affecting the promotion of the technology. So, it's necessary to research the bed cleaning device which can treat sediment effectively and meet the requirements of drip irrigation and the investment is relatively lower. The water drip gravity sinking sand filter tank has better solved the above problems. In this paper, we took the gravity desilting and filter basin of river water drip irrigation as the research object and studied the effects of water-sediment separation by the physical experiment, which the settling basin was 25 m long and the lateral overflow weir is 5 m, 3 m and 2 m long. The results show that the total processing efficiency of sediment can reach more than 55% under the working condition of the structure and the optimal side weir length is 3 m. 'Hie imported maximum sediment concentration is about 1.5 kg/m3 which meet the pool water quality standard. [ABSTRACT FROM AUTHOR]

This paper applied trans-log stochastic frontier analysis (SKA) based panel data model to estimate the water resources efficiency of the industrial sectors and water-saving potential of total 38 industrial sectors in Henan. 'Hie results indicate that the current efficiency of industrial water resources is 0.695 and gross water-saving potential of industrial sectors is 855 million m3; the water-saving potential is relatively high in 12 industrial sectors, which accounts for 92% of the gross water-saving potential of all the 38 industrial sectors in Henan. Baser! on case analysis, it explorer! the problems in analysis of industrial sectors water-saving potential based on SKA. [ABSTRACT FROM AUTHOR]

It is an effective and risky way to solve the contradiction between the large amount of abandoned water and the shortage of water resources in flood season. In this paper, the influence of three uncertainties including flood process, flood time and operating rules on over-storage was analyzed. Considering the risk of dam and downstream flood control, a risk analysis model was established. The highest water level of reservoir and the maximum downstream outflow were taken as the evaluating indexes. The stochastic simulation method was used to solve the model. The study results show that increasing the water level will increase the risk, and the use of appropriate flood regulation rules can reduce the risk. [ABSTRACT FROM AUTHOR]

This paper studied the effects of the dates to start impounding of each reservoir of a cascade reservoir on flood control, water storage , power generation and sediment discharge during the operation of the cascade reservoir. Based on that, a multi-objective decision model of impounding time of a cascade reservoir was established. And then a non-inferior solution set was obtained through the multi-objective particle swarm optimization algorithm. Finally, the non-inferior solution set was evaluated by the combination weight - idea point method, finding an optimal solution. The results indicate that the optimal scheme, compared with the original one, shows an increasing by 59% of the fill storage ratio, and the average annual energy generation increases 28 million kW • h, with the risk rate of flood control and the rate of storage loss only increasing a little. It can significantly improve the profit with little influence on the sediment deposition or security of flood control. [ABSTRACT FROM AUTHOR]

In the southwest of China, where terrain conditions are complicated and highsteep slopes are common, large topographic relief and precipitous mountains are the remarkable characteristics of this area. Traditional geological logging method is field geological mapping using compass and tape, which not only costing huge workload and getting low precision achievements, but also putting life security at risk. By terrestrial laser scanner technology, dense point cloud data of slope can be quickly and precisely attained through noncontact measurement, which can be used to interpret the development regularity and spatial distribution character of the largescale structure planes and joint fissures on the slopes, including structural plane distribution, ascendant attitude, extending length, interval distance and other geological element information to study the combination relation of structural planes and failure patterns. The new geological logging technology has overcome the weakness of the traditional one. This paper took a hydropower slope for an example and described the method of applying this technology in the geologic logging. The interpretation results of geological elements had the characteristics of abundant information and high accuracy. This technology which transformed the complex field work to the data processing in the door, had overturned the traditional survey method and had a certain innovative and advancement. [ABSTRACT FROM AUTHOR]

The quality of earth-rock clam directly affects the safety of the dam. Most of the traditional methods for the evaluation of the quality of the earth-rock dam are mainly controlled by the rolling parameters and the physical parameters of the compaction and eannot quantitatively reflect the safety of the dam. In order to solve this problem, taking Jiulongtan Clay Rockflll Dam in Sichuan Province as an example, this paper put forward a method to evaluate the quality of earth-rock dam based on dam slope stability, in the situation of plenty physical properties and laek of mechanical properties, which took the indicators of mechanical shear strength (cohesion and internal friction angle) and physical indicators (the rate of water content and dry density) of non-linear regression equation to give a detailed physical and mechanical properties of each filling layer and then accordingly the safety factor of anti-sliding stability of the dam slope was cheeked and compared with the original design value and standard value, so as to judge the construction quality. The results show that the method is feasible and can reflect the safety of the dam quantitatively, which has significance of the quality evaluation of similar projects. [ABSTRACT FROM AUTHOR]

In this paper, the analysis was carried out for the circulation background, water vapor characteristics and energy field during a continuous autumn rain process from September 22 to October 4, 2017 in the source region of the Yellow River. The results indicate that the anomalous changes in the south Asian high and the subtropical high made the atmospheric circulation change significantly over the same period. The continuous convergence of the northern cold air and the warm wet air that come from the periphery of the subtropical high led to the occurrence of this continuous rain weather. The strong southerly flow of the west side of the subtropical high continuously transport water vapor from the western Pacific and the South China Sea to the source region of the Yellow River and the water vapor convergence is formed on the 500-400 hPa layer. When the specific humidity of 500 hPa layer is more than 4 g/kg, strong precipitation is easy to occur in the source region of the Yellow River. During the continuous rain period, a large amount of unstable energy accumulates in the lower layer (mainly below 400 hPa), which provides advantageous thermodynamic conditions for the continuous rain. [ABSTRACT FROM AUTHOR]

Based onmeeting the test section selection principle, this paper selected seven typical canal lining with different section forms and lining materials to conduct geometrical parameters hydraulic elements of the prototype monitoring tests. It obtained the channel measured roughness through the measured data calculation by using Manning's equation. Single channel lining material roughness binding complex design and measured data calculated from the weighted average value and the measured roughness groups designed to compare roughness, combined with the specific circumstances of the test section causes roughness size were analyzed. The results show that calibration of roughness value is mainly due to larger cross-sectional geometry is not standard, discrete channel bottom slope and channel siltation. Eventually come to the actual situation of different channel lining material roughness irrigated areas of Ningxia, and gives a variety of masonry materials protective roughness in the range of design, Ningxia Yellow River Irrigation channel design provides the basis for selecting roughness. [ABSTRACT FROM AUTHOR]

The study of flow velocity on grassland slope is of great significance to understand dynamic of erosion deeply and to make scientific decision on soil and water conservation and ecological construction in Loess Plateau. In order to study the variation of flow velocity with rainfall intensity and slope on grassland slope, in the paper, we adopted artificial rainfall experiment to study flow velocity. The results show that: a) under five different rainfall intensities and slopes, variation of flow velocities with time first increase rapidly after becoming increase slowly or stably and relationships between them can be described by the power function equations; b) average runoff velocities on grassland slopes increase with the increase of rainfall intensities and slopes respectively, which can be described by the logarithmic function equation; c) average velocities of grassland slope with rainfall intensities and slopes can be described by the dual logarithmic function equation and in the experiment, the influence of slope on grassland average velocity is greater than the influence of rainfall intensity to the grassland average velocity. [ABSTRACT FROM AUTHOR]

The vertical streambed hydraulic conductivity plays an important role and has great significance in the study of the conversion mechanism of streambed water and groundwater. This paper studied on the determination of the Yurungqash River a total of 25 test points of vertical streambed hydraulic conductivity using seepage meter method and standpipe method. It studied the spatial variation characteristics of vertical streambed hydraulic conductivity with different depths, vertical directions of river and route directions, analyzed the influencing factors of variability, and summarized the dimensional effect of the variability of the vertical streambed hydraulic conductivity. The results show that Yurungqash River vertical streambed hydraulic conductivity is affected by many factors, including floods, aeolian sedimentation and water dynamic effect; in different dimensions, the dominant factors of vertical streambed variability of hydraulic conductivity are different. Variability of vertical streambed hydraulic conductivity can not be determined by a single factor. [ABSTRACT FROM AUTHOR]

Henan Province, as a traditional agricultural province is the core region of grain production in China, where the situation of water resources is complex. The study of matching characteristics of water and soil resources has positive influence on ensuring the agricultural food production. In this paper, considering the portfolio analysis of regional cultivated soil and water resources, the matching coefficients of water and soil resources was calculated firstly based on the data from 2000 to 2014 of 18 cities in Henan Province. Moreover the Lorenz curve was mapped. Therefore the Gini coefficient was calculated to reflect the unbalanced degree of the matching of water and soil resources. Finally, the changing characteristics of the water and soil resources were comparatively analyzed from the spatial and temporal distribution view of Henan Province by considering the parameters of agricultural water and using proportion, water and soil matching coefficient and Gini coefficient. The results show that the degree of the matching of water and soil resources is undesirability and the quantity of water resources is relatively deficient in Henan Province. Therefore, some useful suggestions which contribute to optimization of the matching degree of water and soil resources were put forward to ensure the benign development of the future agriculture in Henan Province. [ABSTRACT FROM AUTHOR]

This paper put forward a calculation method of the ecological water demand of lakes based on dissolved oxygen balance. Taking Nansi Lake as an example, it worked out the atmospheric reoxygenation, aquatic plant photosynthetic oxygen production, consumption for organic pollutants degradation of oxygen consumption and oxygen in the sediment in the aquatic respiration through the research of lake water dissolved oxygen in the source and destination. It is concluded that the Nansi Lake monthly aquatic water requirement under different water quality conditions according to the lake dissolved oxygen balance equation. The lake basic ecological water requirement is found by the number of monthly evaporation and leakage. [ABSTRACT FROM AUTHOR]

With the increasing of running water head and speed of the pumped storage station, the influence of boundary condition on the vibration of the powerhouse became increasingly prominent. In this paper, the three-dimensional finite element model of Hohhot pumped storage power station underground powerhouse was established, using the finite element analysis software ANSYS. The influence of different boundary conditions on powerhouse structure was analyzed. The modal analysis and resonance composite of powerhouse structure were also described. At the same time, the change law of vibration displacement of the plant structure with frequency under the action of hydraulic pulsation was discussed. The results showed that the plant would produce resonance if the vibration response of local structure was not within the allowable range, and needed to take measures to reduce vibration. [ABSTRACT FROM AUTHOR]

In view of numerous monitoring items, wide distribution of monitoring spot, low degree of visualization, needing real-time analysis of monitoring data and other characteristics in the riverside slope monitoring, the safety monitoring information system of the riverside slope with two-dimensional and three-dimensional geographic information visualization and monitoring data management and prediction was developed by using the Visual Studio development platform by the paper. Three-dimensional geographic information model of riverside slope was established by using TIN surface and raster surface respectively. According to the characteristics of the monitoring data, a neural network prediction model was constructed by VB language to analyze and forecast the monitoring data. Through the establishment of Access database, a lot of monitoring data such as displacement, osmotic pressure, rainfall and so on would be summarized for conveniently managing. The engineering example proves that the information system can realize two-dimensional and three-dimensional visualization of riverside slope safety monitoring and manage the monitoring data effectively. Mathematical modeling analysis module can effectively analyze and forecast the monitoring data effectively. [ABSTRACT FROM AUTHOR]

In order to analyze Heihe River middle reaches area of the ecological environment change trend and its formation mechanism，this paper selected the 2000 and 2011 study area remote sensing image data to establish the land use type matrix for remote sensing image data analysis. The results show that:a） in 2000-2011，in the middle reaches of Heihe River，the mainly evolution trend of the ecological environment is from the unused land to cultivated land，other types of land use conversion is also frequently; b) the main factors which the trend of the ecological environment are the results of the interaction between the natural factors and human factors, among them, human factor occupies the mainly position. [ABSTRACT FROM AUTHOR]

Based on the five years (2010-2014) water quality evaluation results of the key water function zones in the Yellow River basin, combining with the distribution of water function zones and water functional properties and using related evaluation methods of quality assessment technical specifications of surface water, this paper analyzed the water quality compliance status and trends in nearly five years systematically. It showed that the water quality in nearly five years tended was improved in the key water function zones of the Yellow River basin. Concerning the existing problems in the evaluation of the past five years, it proposed to build an evaluation information system for key water function zones in the Yellow River basin, carry out special investigation and research on background and the background value, optimize the monitoring station network settings and draw up a reasonable monitoring scheme. [ABSTRACT FROM AUTHOR]

The paper had a brief review on the studies of evolution and regulation of the Yellow River estuary. In response to the new situations like a significant decrease in the regime of the runoff to the Bohai Sea, the single-thread estuarine course having running for decades and the Xiaolangdi Reservoir having been put into operation, the authors put forward recent research objectives on channel evolution, coastline change, key technologies and schemes and measures. There are four key scientific and technological issues to be broken through: a) mechanisms of estuarine channel avulsing; b) responses of the coastal form to river runoff and ocean dynamics; c) multiple spatial and temporal scaled hybrid simulating of the estuarine course changing and; d) flow and sediment allocating of the estuary. There are six important research tasks, i.e. a) the estuarine channel avulsing process and its triggering mechanism; b) dynamic mechanisms of the channel evolution and index system of the course stabilization; c) the coastal evolving processes and its dynamic mechanism; d)multiple spatial and temporal scaled hybrid simulation of the estuarine evolution; e) technologies and demonstration of flow and sediment fluxes allocation of the estuary and; f) operating scheme and measures to stabilize the estuarine course for 100 years. The project achievements will provide technological support for integrated management of the Yellow River estuary and the construction of efficient ecological and economic zone of the delta. [ABSTRACT FROM AUTHOR]

Regionalization of key preventing and controlling areas of soil erosion is not only defined as the basis of soil erosion plans and controlling and measures layout, but also it is regarded as the legal obligations for all levels of government. This paper took the town information as a unit, used qualitative and quantitative analysis, expert consultation and other methods, and conducted a research based on the remote sensing and geographical information system platform for division of key preventing and controlling areas of soil erosion in Gansu Province. It constructed the index system and index parameters of key preventing and controlling areas of soil erosion in Gansu Province. It divided Gansu Province into seven key preventing areas and six key controlling areas. The result of the division reflects the new changes of soil erosion and social economic development in Gansu Province and provides a scientific basis for the preparation of soil and water conservation planning and implementation of soil and water loss control in Gansu Province, other cities and counties. [ABSTRACT FROM AUTHOR]

CFRD's design basically follows the related experience, blanket and coverage zone would be set on the upstream side of panel in general. Under special circumstance, the landslide's occurrence would cause damage to the panel sealing structure, affecting seepage and structure stability of the dam. A CFRD project in northwest of China was analyzed, due to its related emergency. Water level was rapidly decreased around 100 m within 56 hours due to diversion tunnel accident, causing the slide of lower blanket as well as the coverage zone and the damage of panel sealing structure. In this paper, simulation of the accident was carried out by using non-circular sliding method, and it found that the damage of sealing structure was caused by the movement of blanket as well as coverage zone under the interaction of percolation force. At the meantime, the sliding range of the deck pavement and coverage zone was between the 638.76-680.98 m elevation, and the sealing structure in the 11 m range below the landslide accumulation remained possible. In the reinforcement project, the risk was treated carefully. Besides, a series of engineering measures revolving around the seepage control and seepage monitoring of the coverage zone were carried out to ensure safe operation of this project. [ABSTRACT FROM AUTHOR]

Sorts of exciting force will be generated when hydraulic turbine-generator units are operating. Given that generator pedestal is the main supporting part of unit, exciting force directly manifest loads in various directions acting on foundation, so the vibration of generator pedestal is more obvious than other parts. Establishing three-dimensional finite element model of the underground powerhouse, dynamic calculation was applied by using harmonic response method. This paper primarily researched vibration responses of each typical part of generator pedestal under different exerting mode of mechanical horizontal dynamic loads in actual engineering. The result shows that the exerting mode of mechanical horizontal dynamic loads greatly affects the vibration of generator pedestal. According to the practical characteristic of mechanical dynamic loads, appropriate exerting mode is suggested to be adopted to take full account of adverse effect produced by vibration of unit. [ABSTRACT FROM AUTHOR]

This paper reviewed the progress of the extraction of lake water from different remote sensing data. First, it reviewed the advantages and disadvantages of different extraction techniques from commonly used data sources, such as Landsat TM, ETM and MODIS. Second, it summed up the advantages and disadvantages of linear blending, neural network blending and vector blending in order to solve the problems in the extraction of lake water information. Finally, it pointed out that under the conditions of the rapid development of multiple satellites and multi-sensor, the cooperative observation of lake water based on multi-source data is the future development trend, and the scale conversion is the key point in the fusion between spatial matching of multi-source remote sensing data and different inversion results. [ABSTRACT FROM AUTHOR]

Based on the experimental results of the shear capacity of 6 reinforced concrete corbels with steel fiber，this paper discussed the regulations of the STM（strut-and-tie）of the corbels. The regulations of the STM under load were studied by the FEM and the experimental observation. According to this rule, the theoretical formula of the bearing capacity of the corbel was deduced and calculated, and compared with the actual measurement. The result shows that STM is irregular shuttle which has a bigger head than the tail. The bearing capacity of the corbel is influenced by the shear span ratio and the volume of steel fiber. The theoretical formula is well fitted with the actual test value, and can express the actual ultimate load of the corbel accurately. [ABSTRACT FROM AUTHOR]

Based onthe analysis of observation data of Beiluo River basin from 1950 to 2012, including rainfall, runoff, sediment and soil and water conservation, the characteristics of flow and sediment of Beiluo River basin and cause of water and sediment variation were discussed in this paper and the cause of water and sediment variation since 2000 was analyzed quantitatively and qualitatively. The results show that with high sediment concentration, non-uniform annual distribution of water and sediment and unequal distribution during the year, the sources of sediment and water of Beiluo River basin are different. The sediment of Beiluo River basin comes from the upper reaches and runoff mainly comes from the middle-lower reaches. The water and sediment of Beiluo River basin, sediment in particular, is reduced dramatically since 2000, which is mainly due to the reduction of rainfall, rainstorm in particular and the improvement of underlying surface condition. Comparing with the period of 1959-1969, the coming sediment of Beiluo River basin in the period of 2000-2012 had been decreased 85.54 million tons, of which, the sediment reduction affected by human activity is 63.1%-69.2% and the proportion affected by rainfall is 30.8%-36.9%. [ABSTRACT FROM AUTHOR]

This paper briefly introduced the engineering geology and safety monitoring design of the flood discharging tunnel of Qianping Reservoir and expounded in detail the safety monitoring results during the construction period and the stability of the surrounding rock of the tunnel. Through the comparison of safety monitoring instrument data, the deformation, stress law and characteristics of surrounding rock were analyzed in depth. It is concluded that the deformation of surrounding rock is closely related to the step excavation and the deformation increases with the excavation process. In general, the deformation is mainly caused by bursts and is related to bench excavation. When the upper step is excavated, the deformation is relatively smaller and the deformation is relatively larger when the lower step is excavated. If the height of the step excavation is too high and the progress is too fast, the sudden release of stress energy will be too large, resulting in sudden deformation of surrounding rock. The construction of the sluice tunnel of Qianping Reservoir has been completed and the deformation of surrounding rock is in a stable state at this stage. The safety monitoring design should be adjusted accordingly with the progress of the project and the geological conditions revealed. The safety monitoring itself needs to be designed dynamically. [ABSTRACT FROM AUTHOR]

With the development of urban construction in recent years, the problem of urban being waterlogged has become increasingly prominent. At present, the requirements of different standards and codes for controlling being waterlogged in the urban area are also different. Rainwater of the northern cities in China is discharged to the drainage area through a drainage pipe network, which requires that the drainage design scale of urban rainwater pipes should meet the requirements of eliminating urban being waterlogged caused by frequent rainstorms and rare rainstorms. At present, the design of municipal drainage concerning the waterlogged issue generally determines the design scale according to the common occurrence of heavy rain, but it lacks the analysis of the drainage requirement for the heavy rain occurred with low as well as high frequency, however, the urban waterlogged disasters tend to be caused by the rare heavy rain. Through the analysis and calculation of the drainage scale of the center urban area of Yinchuan City, the paper found out the corresponding relation between the drainage criteria of the waterlogged ground with the rainwater main pipe drainage standard, then determined its standard for the handling as well as prevention of the waterlogged disasters by combining the related specifications, hoping that it could provide certain reference to the transformation and construction of other urban rainwater pipe networks.It is concluded that there is a certain corresponding relationship between the regional ground drainage standard and the reappearance period and the scale of the drainage design of the rainwater pipe, especially the scale is drainage flow,so that the urban rainwater pipe can ensure the requirements of the timely elimination of the frequent rainstorm and the elimination of the rare rainstorm in a period. This thought should be reflected in the reconstruction and construction of the urban rainwater pipe network. [ABSTRACT FROM AUTHOR]

Xichuan County is the core source area and the main flood zone of the Mid-Route of the South-to-North Water Transfer Project and also the location of the head work, which the land area of the stone desertification is 745.539 3km2, which accounts for 26.44% of the total land area, which cause very serious problems of soil erosion and regional ecological resources. Slope and lithology are important factors of soil erosion development. Using DEM geological map, etc, the paper studied the land slope and lithology characteristics of stone desertification in Xichuan County based on 3S technique. The results show that the stone desertification in Xichuan County mainly occurred in the area of carbonate formation, range of 8°-25° and carbonate rocks; the total area of 8°-25° is 588.001 5 km2, which accounts for 78.87%; stone desertification land slope increases with the increase of slope at less than 25°, and the slope over 25° decreases with the increase of slope, the minimum area of >35° is 2.679 3km2, which is only 0.36%. The land lithology of Xichuan County is mainly carbonate rock group, clastic rock group, multilayer soil, metamorphic rock group and intrusive rock group. The land distribution area of stone desertification in each rock area is 461.59 km2, 164.54 km2, 119.20 km2, 66.86 km2 and 40.63 kin2 respectively and the average incidence are 58.26%, 23.56%, 1.96%, 30.74% and 24.98% respectively. The distribution area of stone desertification in carbonate formation area is obviously higher than that of other lithologic regions. [ABSTRACT FROM AUTHOR]

Luhun Reservoir is a key control project of the Yihe River, which plays an important role in controlling floods in the lower reaches of the Yihe River. In recent years, many river-crossing bridges have been built on the middle and lower reaches of the Yihe River. Taking a newly built river.crossing bridge near Longmen Town as an example, this paper analyzed the influence of bridge construction on the riverbed erosion and siltation evolution of the river reach where the bridge is located. The results show that the construction of the river.crossing bridge in the river course of Yihe River will have some influence on the erosion of the river course near the bridge site and the rise of the water level and may also cause local adjustment of the river regime. Several bridges will also have cumulative effects on the riverbed evolution. [ABSTRACT FROM AUTHOR]

Ｂａｓｅｄ ｏｎ ｔｈｅ ａｎａｌｙｓｉｓ ｏｆ ｔｈｅ ｐｌａｎｅ ｂｏｕｎｄａｒｙ ａｎｄ ｖｅｒｔｉｃａｌ ｂｏｕｎｄａｒｙ ｏｆ ｔｈｅ Ｋａｒｓｔ ｗａｔｅｒ ｓｙｓｔｅｍ ｉｎ Ｍｉａｎｃｈｉ Ｂａｓｉｎ， ｔｈｉｓ ｐａｐｅｒ ｃａｌｃｕｌａｔｅｄ ｔｈｅ ｇｒｏｕｎｄｗａｔｅｒ ｒｅｓｏｕｒｃｅｓ ｏｆ ｔｈｅ ｋａｒｓｔ ｗａｔｅｒ ｓｙｓｔｅｍ ｂｙ ｕｓｉｎｇ ｅｑｕｉｌｉｂｒｉｕｍ⁃ａｐｐｒｏａｃｈ． Ｔｈｅ ｏｕｔｃｏｍｅｓ ｓｈｏｗ ｔｈａｔ ｔｈｅ ａｎｎｕａｌ ｇｒｏｕｎｄｗａｔｅｒ ｌｅｖｅｌ ｉｓ ｄｅｃｒｅａｓｅｄ ｂｙ １．７９ ｍ ｄｕｒｉｎｇ ｔｈｅ ｂａｌａｎｃｅ ｐｅｒｉｏｄ， ｉｔ ｉｓ ｉｎ ｔｈｅ ｓｔａｔｅ ｏｆ ｐｏｓｉｔｉｖｅ ｂａｌａｎｃｅ ｉｎ ｗｅｔ ｙｅａｒｓ ｗｉｔｈ ｗａｔｅｒ ｌｅｖｅｌ ｉｎｃｒｅａｓｉｎｇ ｂｙ ０．０１ ｍ， ｗｈｉｌｅ ｉｔ ｉｓ ｉｎ ｔｈｅ ｓｔａｔｅ ｏｆ ｎｅｇａｔｉｖｅ ｂａｌａｎｃｅ ｉｎ ｎｏｒｍａｌ ａｎｄ ｄｒｙ ｙｅａｒｓ， ｔｈｅ ｇｒｏｕｎｄｗａｔｅｒ ｌｅｖｅｌ ｄｏｗｎｒａｎｇｅ ｉｓ ４．６０ ｍ ｉｎ ｎｏｒｍａｌ ｙｅａｒｓ ａｎｄ １６．８９ ｍ ｉｎ ｄｒｙ ｙｅａｒｓ． Ｔｈｅ ｇｒｏｕｎｄｗａｔｅｒ ｌｅｖｅｌ ｉｓ ｉｎ ａ ｃｏｎｔｉｎｕｏｕｓ ｄｅｃｌｉｎｅ ａｃｃｏｒｄｉｎｇ ｔｏ ｔｈｅ ａｎａｌｙｓｉｓ ｄａｔａ ｏｆ ｔｈｅ ｇｒｏｕｎｄｗａｔｅｒ ｌｅｖｅｌ ｏｆ ｂｏｒｅｈｏｌｅｓ ｗｉｔｈｉｎ ｔｈｅ ｒｅｇｉｏｎ； ｔｈｅ ｇｒｏｕｎｄｗａｔｅｒ ｌｅｖｅｌ ｈａｓ ｂｅｅｎ ｄｅｃｒｅａｓｅｄ ｂｙ ４０－１４０ ｍ ｄｕｒｉｎｇ ｔｈｅ ｐｅｒｉｏｄ ｏｆ １９８４－２００８， ｔｈｅ ａｎｎｕａｌ ｄｅｃｌｉｎｅ ｏｆ ｔｈｅ ａｖｅｒａｇｅ ｇｒｏｕｎｄｗａｔｅｒ ｌｅｖｅｌ ｏｆ ｂｏｒｅｈｏｌｅｓ ｉｓ ５．６８ ｍ， ｔｈｅ ｃａｌｃｕｌａｔｉｏｎ ｒｅｓｕｌｔｓ ｆｉｔ ｗｅｌｌ ｗｉｔｈ ｔｈｅ ａｃｔｕａｌ ｄａｔａ ｏｆ ｏｂｓｅｒｖａｔｉｏｎ ｂｏｒｅｈｏｌｅｓ． Ｔｈｅ ｇｒｏｕｎｄｗａｔｅｒ ｒｅｃｈａｒｇｅ ｍａｉｎｌｙ ｃｏｍｅｓ ｆｒｏｍ ｉｎｆｉｌｔｒａｔｉｏｎ ｏｆ ｐｒｅｃｉｐｉｔａｔｉｏｎ， ｍａｋｉｎｇ ｕｐ ７４．０％， ｗｈｉｌｅ ｔｈｅ ｄｉｓｃｈａｒｇｅ ｃｏｍｅｓ ｆｒｏｍ ｅｘｐｌｏｉｔａｔｉｏｎ ｏｆ ｗａｔｅｒ ｓｏｕｒｃｅ， ｃｏｖｅｒｉｎｇ ａｂｏｕｔ ９７．５％. [ABSTRACT FROM AUTHOR]

The slow flow under the ice-cover can be approximated to laminar flow between two parallel inclined plates, which provides a basis for the theoretical solution of the vertical flow velocity distribution under the ice-cover. In this paper, the vertical velocity distributions of laminar flow in open channel and that under ice-cover were studied comparatively by means of theoretical analysis. It was shown that the vertical velocity distribution of laminar flow in open channel and that under ice-cover could be expressed in a unified parabolic form, however, the vertical velocity distribution of the laminar flow in open channel could be completely determined, but which of the laminar flow under ice-cover varied with the longitudinal pressure gradient. At the same time, flow velocity in vertical line, the maximum value of vertical velocity, the average value of vertical velocity, the unit discharge and the maximum velocity gradient of laminar flow under ice-cover were all less than the corresponding values of the laminar flow in the open channel. The results show that the ice-cover affects the discharge by affecting the vertical velocity distribution and both the discharge and the water transport rate are greatly reduced. In order to ensure the adequate water supply of water conveyance channels in winter, the adverse effects of ice-cover should be avoided. [ABSTRACT FROM AUTHOR]

Land use in the beach area of the Lower Yellow River is closely related to the production and life of the people in the beach area and the safety of flood control in the lower reaches of the Yellow River. This paper summarized the investigation and change of land use in the beach area of the lower Yellow River in recent years, the different viewpoints of land use and flood control safety, and the many solutions of "people and water competing for land", analyzed the new trend of land use of floodplain immigrants, and finally proposed to strengthen the unified planning of land use and flood control in beach area. Objective to provide new ideas and references for the development and utilization of land in the Yellow River beach area and the control of the Yellow River. [ABSTRACT FROM AUTHOR]

The energy dissipation characteristic of stepped spillway is one of most important research, while energy dissipation ratio cannot effectively reflect the value of the steps in the aspect of energy dissipation. In order to accurately reflect the contribution of step structure to the flow energy dissipation, the paper conducted the comparative analysis on mechanism of energy dissipation between the stepped spillway and corresponding smooth spillway. The hydraulic model test on skimming flow had been conducted by using three different chute slopes of 26.56°, 38.66°and 51.30° at a step height of 0.5 m, 1.0 m and 2.0 m, focusing on the relationship of relative energy dissipation ratio with ratio of the length of flow path and depth, step height, unit discharge and bottom slope. Experimental results show that the relative energy dissipation ratio varies linearly with ratio of the length of flow path and depth and the linearly correlation coefficient between them is 0.984 6-0.996 2. The unit discharge, step height and bottom slope have a great influence on the relative energy dissipation ratio that increase with it. The result manifests that it is necessary of studying the relative energy dissipation and the unique linear relationship provides an important theory for further exploring the mechanism of energy dissipation of stepped spillway. [ABSTRACT FROM AUTHOR]