Critical discharge at Datong for controlling operation of South-to-North Water Transfer Project in dry seasons

Previous research shows that there is a strong correlation between saltwater intrusion in the Yangtze Estuary and discharge at Datong. In the near future, the discharge of the Yangtze River during dry seasons will decrease due to the construction and operation of large water diversion projects, including the South-to-North Water Transfer Project, which will further exacerbate saltwater intrusion in the estuary. In this paper, a nested 1D river network model and a 2D saltwater numerical model are used to associate saltwater intrusion in the Yangtze Estuary with different values of discharge at Datong. It is concluded that 13 000 m3/s is the critical discharge at Datong for preventing saltwater intrusion and controlling the volume of water transferred by the South-to-North Water Transfer Project. Furthermore, based on the analysis of river discharge from Datong to Xuliujing and in consideration of the influence of all of the water diversion projects, operation schemes are proposed for the Eastern Route of the South-to-North Water Transfer Project for different hydrological years.

Geological conditions and key rock mechanics issues in the Western Route of South-to-North Water Transfer Project

In terms of special geological conditions of the Western Route of South-to-North Water Transfer Project, the classification method for surrounding rocks is discussed by combining with the construction method of tunnel boring machine （TBM）. The classification standard of surrounding rocks is put forward on the basis of physical simulations and engineering practices. Damage, deformation and evolution of surrounding rocks induced by TBM excavation are discussed. Meanwhile, the long-term deformation mechanisms and stability of surrounding rocks are also studied. On this basis, a three-dimensional constitutive model for interbedded sandstone slate and a fiat shell-joint element-foundation system for calculating internal forces of segment lining are established. The deformation features of surrounding rocks of deep and steep interbedded sandstone slate and their influences on internal forces of segment lining are presented. Finally, the design methods of segment lining constructed in deep and steep flysch are proposed.

Forecasting Loss of Ecosystem Service Value Using a BP Network: A Case Study of the Impact of the South-to-north Water Transfer Project on the Ecological Environmental in Xiangfan, Hubei Province, China

Objective To recognize and assess the impact of the South-to-north Water Transfer Project (SNWTP) on the ecological environment of Xiangfan, Hubei Province, situated in the water-out area, and develop sound scientific countermeasures. Methods A three-layer BP network was built to simulate topology and process of the eco-economy system of Xiangfan. Historical data of ecological environmental factors and socio-economic factors as inputs, and corresponding historical data of ecosystem service value (ESV) and GDP as target outputs, were presented to train and test the network. When predicted input data after 2001 were presented to trained network as generalization sets, ESVs and GDPs of 2002, 2003, 2004... till 2050 were simulated as output in succession. Results Up to 2050, the area would have suffered an accumulative total ESV loss of RMB 104.9 billion, which accounted for 37.36% of the present ESV. The coinstantaneous GDP would change asynchronously with ESV, it would go through an up-to-down process and finally lose RMB89.3 billion, which accounted for 18.71% of 2001. Conclusions The simulation indicates that ESV loss means damage to the capability of socio-economic sustainable development, and suggests that artificial neural networks (ANNs) provide a feasible and effective method and have an important potential in ESV modeling.

Evolution trend of the water quality in Dongping Lake after South-North Water Transfer Project in China

To investigate the evolution trend of water quality in Dongping Lake after South-North Water Transfer Project operation as well as to ensure the safe usage of the water receiving areas, water samples were collected and determined before and after water delivery in different hydrological seasons. Then, comprehensive pollution index method, comprehensive nutrition state index method and health risk assessment model were utilized to evaluate the quality, nutrition, and health risk of Dongping Lake water. Results showed that the quality of Dongping Lake water still met level Ⅲ (light pollution) no matter before or after water delivery. The nutrition state was improved from light eutropher before water delivery to mesotropher after water delivery. The health risk level was reduced from high-medium before water delivery to medium level after water delivery. In summary, the operation of the eastern route of South-North Water Transfer Project is beneficial for water environment improvement of Dongping Lake.

Energy model of projected transfer with additional mechanical force in the welding process

Based on the theory of electrodynamics and other relational subjects,through introducing “Surface Evolver” as the means of FEM analysis, by computing and describing the energy (electromagnetic, gravity, and so on) in the droplet transfer system, an energy model was accomplished for studying the mechanism of projected transfer mode.Furthermore, the behavior of droplet transfer was studied by analyzing its menisci with FEM, and the theoretical results coincide well with the experiment results.

Eco-environmental benefit assessment of China's South-North Water Transfer Scheme——the middle route project

This paper assess the eco-environmental benefits that may come from the middle route project of China's South-North Water Transfer Scheme(SNWT) with principles and methods of eco-economics and planning reports of SNWT's middle route project. Some benefits were calculated in monetary units. To make sure that the results can be comparable with normal monetary indices, concrete assessment objects and the parameters are prudently selected according to the major characteristics of the project and its water import region. Primary assessment revealed that in different project construction stages, the benefit could be more than 13 07 billion RMB Yuan in 2010 and 19 79 billion RMB Yuan in 2030, respectively. The monetary value tends to increase with social-economic development. To realize these potential benefits, however, calls for more endeavors.

Preliminary Study on Strategic Water Transfer Project in Western China

Strategic Water Transfer Project of Western China will transfer water from the Dadu river, the Yalong river, the Jinsha river, the Lancang river and the Nujiang river to the Daliushu project as head work of main canal on the Yellow river. And then,the water will be diverted to Neimongol and Xinjiang Uygur autonomous regions,with transfered annual volume of water 80 billion m\+3. The project possesses great comprehensive benefit. The construction of the project will not only change the appearance of the whole Northwest China, but also open up a wide way for the sustainable development of China in future.

LONG AND DEEP DIVERSION TUNNELS OF 1^(ST) STAGE PROJECT IN WEST ROUTE OF SOUTH-NORTH WATER TRANSFER PROJECT

West Route of South-North Water Transfer Project,situated in southeastern Qinghai-Tibet Plateau,is a giant project,which will deliver 17 billion m3 of water from the main stream and tributaries upstream of the Yangtze River to the upper reaches of the Yellow River. It is to be constructed in 3 stages, of which the 1st stage project includes delivering 4 billion m3 of water by gravity from two tributaries of Yalong River and three tributaries of Dadu River. The project consists of 5 dams,7 tunnels and a channel in series,with the dam height of 63～123 m and water transfer length of 260.3 km,of which the tunnels measure 244.1 km. The special climatic,environmental and geologic conditions make the project much more complicated in construction,especially 3 tunnels with the length longer than 50 km each create challenges to the technical requirements of engineering survey,design and construction.

Water Security Situation in Haihe River Basin after South-to-North Water Transfer Project

The over-exploitation of water resources in the Haihe River Basin （HRB） has now become a serious problem. This is clearly evidenced by the fact that many local rivers and lakes are drying up and the total amount of over-exploited groundwater has reached over 1000×10^8m^3. It is important to note that the exploitation of water resources in HRB was reasonable before 1979. After 1980, however, over-exploitation happened with an annual average amount of 40×10^8m^3. Both the dry season and rapid economic growth in HRB took place at the same time. Therefore, the over-exploitation of water in HRB was actually the negative result of the conjunction of a continuous dry season and rapid economic growth. So the over-exploitation would not be as serious as it is today if either of the above two stopped. After the first stage of south-to-north water transfer project, the water shortage problem in HRB could be eased for the following reasons： firstly, water transfer project will bring to the Basin 60x108m3 water resources; secondly, a wet season will come back eventually according to natural law of climate variability; finally, its agricultural and industrial use and total water consumption all have decreased from the peak value, so that the groundwater table will raise certainly and ecological water in rivers and lakes that were dried-up will be partly restored. In the future, the main problem of water resources security in HRB will include water pollution, operation risk of the south-to-north water transfer project, groundwater pollution and engineering geological hazards that may be brought by groundwater rise. The proposed countermeasures are as follows： keeping strengthening water demand management, raising water price as well as subsidies for the low- income family and improving other water related policies, preventing and dealing with water pollution seriously and getting fully prepared for the operation of south-to-north water transfer project.

Estimating minimum ecological water required of the western route first stage project of China＇s south-to-north water transfer scheme for water exporting rivers

It is well known that there is abundant water resources in basin of the Yangtze River, the first largest river in China, which is mainly located in Southern China. However, water resources is very scarce in the basin of the Yellow River, which is mainly located in Northern China. So the western route project of south-north water transfer scheme （WRP-SNWTS） aims to transfer water from the Yangtze River to the Yellow River. The area of WRP-SNWT, located in the upper reaches of the Yangtze River and the main areas of Sichuan and the marginal areas of the Qinghai-Tibet Plateau, has sufficient water resources but fragile ecology and environment. Therefore, it is necessary for WRP-SNWT to analyze the ecology water required. Based on the planning principles of from low elevation to high elevation, from small to large, from short to long and from easy to difficulty, the WRP-SNWT will be constructed through three stage projects. The western route first stage project of the south-north water transfer scheme （WRFST-SNWTS） is planned to transfer 4×10^9m^3/a from six tributaries of the Yalong river and from Dadu river to Jiaqu of Yellow River.. Daqu river and Niqu river are the branches of Xianshui river. Sequ river, Duke river, Make river and Ake river are the branches of Dadu river, which account for 65-70% of the total river run-off. It need more research and the rest run-off can satisfy channel ecology water required. According to analysis ecological water required which mainly satisfy for aquicolous biology in water-exporting region, such as low air temperature. Fish and aquicolous biology main living from May to August, and rivers are iced up from December to March of next year, ecology water required mainly for fish and aquicolous biology. The flow criterion of Tennant method is modified. The ecology water required of WRFSP-SNWTS is estimated by the flow data of Zhuwo gauging station, Zhuba gauging station, Chuosijia gauging station and Zumuzu gauging station. The result show that the ecology water required calculated by modified Tennant less 1 l percent than that of Tennant. This estimating result can supply more water resources for transferring to Yellow River. Meanwhile, this can supply gist for research transferring water of WRFSP-SNWTS.

Price Analysis of Water Supply for South-to-North Water Transfer Project

The factors influencing the water supply price of a hydraulic project include natural conditions and economic policies. This paper thoroughly demonstrates the water price of South-to-North Water Transfer Project from the viewpoint of economic policies. It is considered that if the project is assigned as a profitable one and built depending on commercial loan from bank completely or mostly, the water price will be too high to be undertaken by users,and if the project places the public good at first while considering the economic benefit, its investment mainly relies on the state (national or local governments) appropriation and self-raised funds and a little from the bank loan on favorable terms, the price determined according to the principle of satisfying the cost and reasonable profit will be relatively lower and can be undertaken by the users in the North China where water shortage is serious. The problem of higher water price of agricultural irrigation to the north of the Yellow River can be tackled by taking measures such as "compensating agriculture by industry" according to foreign practical experiences and relevant suggestions.

Coupling interaction between biodiversity and aquatic habitat area in Western Route Project vicinity

The Western Route of the South-to-North Water Transfer Project will divert water from the upper Yangtze River and its tributaries, the Dadu River and Yalong River, to the upper Yellow River. The project may ease the water shortage in the Yellow River Basin. However, it may also have some effects on the ecosystem in the upper Yangtze River Basin. Benthic invertebrates play an important role in the river ecosystem, particularly in the circulation of materials and nutrition. Benthic invertebrates are widely used to quickly assess river ecosystems because of their rapid response to changes in the water environment. The diversity of benthic invertebrates is closely associated with the aquatic habitat area. This study examined this interaction by sampling the benthic invertebrates in an expanding area. The conclusions are that the diversity of benthic invertebrates begins to decrease when the aquatic habitat area is reduced to 45% of the original area, and decreases dramatically when the aquatic habitat area is reduced to 10% of the original area. The aquatic habitat area should be kept at more than 45% of the original area in order to maintain the significant diversity of benthic invertebrates.

A Cooperative Activity on Quenching Process Simulation Japanese IMS-VHT Project on the Benchmark Analysis and Experiment

Japanese IMS-VHT project on the Virtual Heat Treatment tool for monitoring and optimising HT process in relation with the international cooperative programs is briefly introduced. This project motivates to develop virtual tools for computer to optimize the heat treatment condition and to support decision for HT operation by knowledge based database in addition to process simulation. As one of the activities with the cooperation of the Society of Materials Science, Japan and the Japan Society for Heat Treatment, a benchmark project is undergoing. This includes simulation of carburized quenching process of a cylinder, disc, and ring as well as a helical gear by use of common data of materials properties and cooling characteristics by several available simulation programs. A part of the newly obtained results is presented as an interim report.

长距离调水工程安全风险综合评估

以某跨流域、跨多省市的长距离调水工程为例,分析工程安全面临的各类风险事件,确定两座节制闸之间的运行调度渠段为风险评估单元,发展基于层次分析法的风险综合评估模型;以一梁式输水渡槽为例,阐释建筑物风险因子识别、风险事件分析和风险等级标准划分的方法,描述风险评估过程;以该渡槽所在的运行调度渠段为评估单元,采用层次分析法进行风险综合评估;在此基础上,对其余运行调度渠段进行风险综合评估,讨论造成较大风险的主要原因。结果表明:提出的方法辨识出了较大风险的运行调度渠段,造成运行调度渠段工程安全风险综合评估结果为较大风险的因素可归结为左岸水库溃坝或超调水工程防洪标准泄洪导致的风险、交叉河道过流能力不足风险以及左排下游通道排水不畅风险等,进而有针对性地提出了风险管控措施。研究结果可为类似长距离调水工程安全风险综合评估和管控提供参考。

南水北调东线一期工程受水区生态环境效益演变

研究南水北调东线一期工程通水以来受水区生态环境效益的演变态势,对南水北调后续工程高质量建设、加快构建国家水网以及促进工程综合效益发挥有决策参考作用。以定性定量相结合的方式分析东线一期工程在优化水资源配置、保障饮水安全、复苏河湖生态环境和畅通南北经济循环等方面的作用,进而结合层次分析法,从直接效益和间接效益2个方面,筛选构建东线一期工程受水区生态环境效益评价指标体系,主要包括工程年供水量、水质改善度、生态补水量、地下水压采量、地下水水位、水域面积、绿地面积和涵养水源等,并采用VlseKriterijumska Optimizacija I Kompromisno Resenje(VIKOR)多准则妥协解排序方法对南水北调东线一期工程通水以来即2013-2022年受水区生态环境效益演变态势进行分析。结果表明:南水北调东线一期工程通水的10年以来,受水区的生态环境整体复苏效果明显,近3年排序值保持在0.8以上;受降水偏枯进而影响地下水开采量和地下水水位等因素影响,2019年间接生态环境效益下降29.2%,之后迅速恢复并保持稳定。在分析直接效益和间接效益演变的基础上,从工程提质增效、提高工程水质状况以及完善体制机制建设等方面提出东线一期工程进一步促进受水区生态环境持续改善的策略和建议,以期为东线工程及受水区生态环境保护及高质量发展相关研究、决策制定等提供参考。

基于支持向量机的蓄水工程土地利用分类与动态变化

为进一步恢复和重建蓄水工程建成前后土地利用变化的历史过程,更好掌握和预报土地利用转移方向,本文利用支持向量机理论开展了土地利用类型解译的适应性研究,通过梳理土地利用动态变化,剖析了蓄水工程建成前后土地利用结构的自适应调节能力和演变方向。结果表明:(1)依靠自学习和自适应等优势能力,支持向量机解译土地利用分类的总体精度高达91.7%、Kappa系数为0.90;除耕地生产者精度相对较低外,水体、林地等其他土地类型具有较高的分类识别能力。(2)利用谷歌地球引擎(GEE)平台梳理土地利用类型演变过程发现,受“三北防护林”工程二阶段(2001—2020年)等项目实施影响,建设用地、林地面积出现较大增幅,其中,林地面积较2000年实施初期增加了近5倍。(3)工程建设运行后林地和建设用地近2/3面积保持了原貌,水体和未利用土地受水利和城建工程影响,原貌类型超过65%以上面积变成了其他类型;“三北防护林”工程加快了林地面积的增加和草地植被覆盖度的提高,低覆盖度草地转移到中、高覆盖度草地的面积净增幅达48.0%、50.2%。

协同推进南水北调后续工程和长江经济带高质量发展

推动长江经济带高质量发展,是以习近平同志为核心的党中央作出的重大决策,是关系党和国家事业发展全局的重大战略。南水北调东、中、西三条线均以长江为水源,是跨流域跨区域配置水资源的骨干工程,是国家水网的主骨架和大动脉,在保障国家经济安全、粮食安全、生态安全等方面具有基础性、战略性作用。两者联系紧密,互促共生。文章通过对长江经济带高质量发展内涵的分析,以及在国家水安全保障、长江经济带高质量发展对南水北调高质量发展的具体要求梳理的基础上,对共同推进南水北调和长江经济带高质量发展提出了初步的认识和思考。

不同调水方式对巢湖水质影响模拟

引调水工程是目前用来改善湖泊水质的重要手段,然而引调水的调水路线、来水水量以及来水水质对湖泊水质改善效果都至关重要。本文以“引江济巢”工程为例,针对巢湖的浅水湖泊特征,考虑引调水入湖后不仅对水量和水质有直接改善作用,还可能因为湖区水动力条件改变及内源释放影响水质,通过构建二维水动力水质模型,模拟不同调水路线、水量下湖区水动力条件,进一步考虑不同来水水质和底泥释放对水质改善的影响。结果显示,调水对流场的扰动在丰水年较弱、枯水年较强,流量对湖区水质影响随流量增大而增强,来水水质的优劣是决定湖区水体水质是否改善的关键。整体而言,西湖区受调水影响较小,东湖区能够对全湖水质变化起到指示作用。调水方案应基于湖泊实际水量与水质状态综合考虑调水流量与水质制定。

南水北调西线工程水源区和受水区降水变化及丰枯遭遇特征分析

基于规划中的南水北调西线工程区域内274个国家气象站1961—2022年逐日降水资料,分析了西线工程水源区和受水区年和四季降水量的时空分布特征,以及两区降水的丰枯遭遇特征。结果表明:近62年来,南水北调西线工程水源区年降水量总体呈增多趋势,而受水区年降水量没有明显变化趋势;夏、冬季水源区和受水区降水量均增多,春、秋季水源区降水量增多而受水区降水量减少;年和春、夏、秋季水源区枯水频率均低于受水区枯水频率,并且水源区枯水频率呈减少趋势,而丰水频率呈增加趋势;水源区和受水区年和四季降水丰枯异步频率普遍在60%以上,远大于丰枯同步频率,有利调水的5种丰枯遭遇在年和春、夏、秋季发生频率均超过50%。总体而言,南水北调西线工程水源区和受水区的降水具有较强的丰枯补偿性,且1971年以来有利调水发生频次呈增加趋势,理论上存在保证供水的可能性。但水源区出现连续枯水年的频次较多。因此,在南水北调西线工程规划设计和运行调度时需充分考虑水源区和受水区降水的变化。

江苏省江水北调工程水量调度

江水北调工程以向江苏境内工农业及城乡生活供水为主,同时保障改善洪泽湖、骆马湖生态,但工程运行现状存在运行成本高、湖泊弃水量大等不足。为此,采用模拟和优化技术相结合的方式,以供水缺额最小、湖泊水位超限制最小和泵站运行成本最低为优先级设定目标函数,构建江水北调工程年水量调度概化模型,开展不同水平年、不同补湖水位以及高水低用3种调度情景分析。结果表明:骆马湖调蓄库容小,调水运行期使得水位波动频繁,中运河泵站会同频开启补湖,且容易达到输水能力上限;适当降低洪泽湖补湖水位,可充分利用湖泊富余水量,使调水成本降低;完全禁止骆马湖高水低用会加重洪泽湖以下梯级线路供水任务的运行负担,同时增加骆马湖的弃水量,适当允许高水低用可使成本减小,减少泵站抽水任务。建立的模型以及相关研究成果可为江水北调工程调度运行提供一定参考。