Penalty model for delay of bidding section construction period in South-to-North Water Diversion Eastern Route Project from perspective of programs

According to the multi-project and program management theory, this paper analyzes the program generation principle and establishes a program based on progress goals. On the basis of the present situation of calculation of penalty for delay of the bidding section construction period with the critical path method, we studied the effects of contractor-induced delay of the bidding section construction period in detail, including the effects on the construction period of the bidding section itself, the earliest start times of the next bidding section and other subsequent bidding sections, and the construction period of the program, and then constructed a penalty model for delay of the bidding section construction period from the perspective of programs. Using the penalty model, we conducted a practical analysis of penalty for delay of the construction period of the Baoying station program in the South-to-North Water Diversion Project. The model can help determine the amount of penalty for delay of the construction period in bidding sections scientifically and reasonably,

Land Cover Changes and Drivers in the Water Source Area of the Middle Route of the South-to-North Water Diversion Project in China from 2000 to 2015

The Middle Route of the South-to-North Water Diversion Project(MR-SNWDP)in China,with construction beginning in 2003,diverts water from Danjiangkou Reservoir to North China for residential,agriculture and industrial use.The water source area of the MR-SNWDP is the region that is most sensitive to and most affected by the construction of this water diversion project.In this study,we used Landsat Thematic Mapper(TM)and HJ-1 A/B images from 2000 to 2015 by an object-based approach with a hierarchical classification method for mapping land cover in the water source area.The changes in land cover were illuminated by transfer matrixes,single dynamic degree,slope zones and fractional vegetation cover(FVC).The results indicated that the area of cropland decreased by 31%and was replaced mainly by shrub over the past 15 years,whereas forest and settlements showed continuous increases of 29.2% and 77.7%,respectively.The changes in cropland were obvious in all slope zones and decreased most remarkably(–43.8%)in the slope zone above 25°.Compared to the FVC of forest and shrub,significant improvement was exhibited in the FVC of grassland,with a growth rate of 16.6%.We concluded that local policies,including economic development,water conservation and immigration resulting from the construction of the MR-SNWDP,were the main drivers of land cover changes;notably,they stimulated the substantial and rapid expansion of settlements,doubled the wetlands and drove the transformation from cropland to settlements in immigration areas.

IMPACTS OF THE SOUTH-TO-NORTH WATER DIVERSION PROJECTS (MIDDLE ROUTE)ON THE WATER ENVIRONMENT OF THE MIDDLE AND LOWER REACHES OF THE HANJIANG RIVER

In this paper, according to the rule of unbalanced sediment transport and the analysis of field data, different water diversion schemes were theoretically studied, including the erosion and sedimentation trend as well as their impacts on the environment of the middle and lower reaches of the Hanjiang River. The results showed that the 95×10 8m 3 water diversion scheme will cause less erosion and water level decrease than the 15×10 8m 3 water diversion scheme. Using a water diversion scheme of 95×10 8m 3, the decrease of water quantity can impact the river hydrodynamic regime substantially and the environments of the middle and lower reaches of the Hanjiang River will be greatly affected. It is therefore necessary to develop new water resources or build projects to meet the need of the environment and the needs for navigation.

Critical chain construction with multi-resource constraints based on portfolio technology in South-to-North Water Diversion Project

Recently, the critical chain study has become a hot issue in the project management research field. The construction of the critical chain with multi-resource constraints is a new research subject. According to the system analysis theory and project portfolio theory, this paper discusses the creation of project portfolios based on the similarity principle and gives the definition of priority in multi-resource allocation based on quantitative analysis. A model with multi-resource constraints, which can be applied to the critical chain construction of the A-bid section in the South-to-North Water Diversion Project, was proposed. Contrast analysis with the comprehensive treatment construction method and aggressive treatment construction method was carried out. This paper also makes suggestions for further research directions and subjects, which will be useful in improving the theories in relevant research fields.

Reliability model of organization management chain of South-to-North Water Diversion Project during construction period

In order to analyze the indispensability of the organization management chain of the South-to-North Water Diversion Project （SNWDP）, two basic forms （series connection state and mixed state of both series connection and parallel connection） of the organization management chain can be abstracted. The indispensability of each form has been studied and is described in this paper. Through analysis of the reliability of the two basic forms, reliability models of the organization management chain in the series connection state and the mixed state of both series connection and parallel connection have been set up.

Impact of the eastern water diversion from the south to the north project on the saltwater intrusion in the Changjiang Estuary in China

The south to the north project (WDP) on the saltwater intrusion in the Changjiang Estuary is studied by the improved three-dimensionai (3D) numerical model.The net unit width flux in the Changjiang Estuary as well as the sectional salt flux is calculated in the North Branch (NB),the South Branch (SB),the North Channel (NC),the South Channel (SC),the North Passage (NP) and the South Passage (SP),respectively.The net seaward water flux in the SB is reduced,and the net water flux spilling over from the NB to the SB is enhanced after the eastern WDP.Under the mean river discharge condition in the dry season,the net salt flux spilling over from the NB to the SB is increased by 2.09 t/s and 0.52 t/s during the spring and neap tides,respectively,due to the eastern WDP.The saltwater intrusion in the Changjiang Estuary is enhanced by the eastern WDP.Compared with that during the spring tide,the net water diversion ratio during the neap tide in the NC is smaller,and thus the enhancement of the saltwater intrusion by the eastern WDP is smaller in the NC,and larger in the NP and the SP.The tidally averaged surface salinity at the water intakes of the Dongfengxisha Reservoir,the Chenhang Reservoir and the Qingcaosha Reservoir rises both during the spring and neap tides.

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.

Water-saving potential evaluation of water-receiving regions in Shandong province on the East Route of the South-to-North Water Transfer Project of China

Taking 13 water-receiving areas on the East Route of the South-to-North Water Diversion Project(ERSNWDP)in Shandong Province as the study area,and comparing it with Jiangsu Province on the ERSNWDP and the Middle Route of the South-to-North(MRSNWDP),the current water-saving potential of the water-receiving areas within the municipalities of Shandong was analyzed.Different water-saving scenarios were constructed and analyzed with key water-saving indexes in various industries.These indexes include the effective utilization coefficient of farmland irrigation water,total water consumption of industrial sectors with an added value of over 10000 RMB,average leakage rate of the urban public water supply pipe network and the penetration rate of water-saving appliances.Based on the scenarios,comprehensive water-saving potential of the 13 water-receiving area cities was calculated.The results show that the water-saving potential of the study area is at a relative high level.However,some cities still have a certain amount of water-saving potential for agriculture and industry to be elevated.Under the recommended water-saving scenario,the water-saving potential is 1.134 billion m3,accounting for 5.33%of the current total water consumption,of which 460 million m3 is in agriculture,600 million m3 in industry,is and 74.20 million m3 in urban domestic sector.Comprehensive water-saving measures for the study area were proposed from the aspects of agricultural,industrial and domestic water uses.Agricultural and industrial water saving are more significant.The major cities for agricultural water saving include Jining City,Heze City,Weifang City and Jinan City;the focus cities of industrial water saving mainly include Weihai City,Jining City and Qingdao City and etc.;the key water-saving areas for urban use mainly include Zaozhuang City,Jining City and Heze City.

Water diversion and agricultural production:Evidence from China

Water diversion can alleviate water shortages caused by the uneven distribution of water resources.China’s Southto-North Water Diversion Project(SNWD)is the largest water diversion project worldwide.Based on the prefecturelevel data of China’s Huang-Huai-Hai Plain from 2000 to 2020,this study employs an empirical strategy of Differencesin-Differences(DID)to analyze the impact of SNWD on agricultural production.The results show that SNWD has significantly increased agricultural production,measured by the agricultural value added.The estimated results of the benchmark model remain robust when the contemporaneous policy is addressed,an alternative outcome is used,subsamples are estimated,and alternative estimation techniques are employed.This study argues that the potential impact mechanism may be that SNWD significantly increases the acreage for cash crops but reduces that for grain crops.Heterogeneity analysis shows that in prefectures with high temperature or land potential,SNWD’s impact on agricultural value added is relatively low.In contrast,in areas with prolonged sunshine or high slopes,SNWD’s impact on agricultural value added is relatively large.Given the low added value of grain crops,the government should consider strengthening food security by subsidizing water supply to sustain grain production.

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.

On conservation and development of architecture and environment in the construction of large-scale national infrastructure——Exemplified by the Jiangsu Section of the Eastern Route South-to-North Water Diversion Project

The water-diverting route project’s characteristics,natural landscapes,and histories and humanism of the Jiangsu Section of the Eastern Route South-to-North Water Diversion Project were systemically analyzed through proposing and studying the canal culture routes,the water resources heritage corridors,the landscape and recreation corridors,and the town economic corridors.The station areas along the water-diverting route were scientifically zoned and graded through quantitative and qualitative synthetic methods.Both planning compendiums and construction controlling methods were proposed based on the project grades of points,lines,and areas.Conservation and development of architecture and environment in the large-scale national infrastructure construction were explored systemically.Theories and methods of developing harmonious water-supplying functions,ecological functions,landscape effects,and cultural effects of large-scale water resources were examined.

Computing payment for ecosystem services in watersheds: An analysis of the Middle Route Project of South-to-North Water Diversion in China

Payment for ecosystem services （PES） has attracted considerable attention as an economic incentive for promoting natural resource management recently. As emphasis has been placed on using the incentive-based mechanism by the central government, rapid progress on PES research and practice has been achieved. However PES still faces many difficulties. A key issue is the lack of a fully-fledged theory and method to clearly define the design scope, accounting and feasibility of PES criteria. An improved watershed criteria model was developed in light of research on PES practices in China, investigations on the water source area for the Middle Route Project of South-to-North Water Diversion and ecosystem services outflows theory. The basic principle of assessment is the direct and opportunity cost for ecological conservation and environmental protection in the water source area deduct nationally-financed PES and internal effect. Then the scope and the criteria methods were determined, and internal effect was put forward to define benefits brought from water source area. Finally, Shiyan City, which is the main water source area for the Project of Water Diversion, was analyzed by this model and its payment was calculated. The results showed that： （1） during 2003–2050, the total direct cost and opportunity cost would reach up to 262.70 billion and 256.33 billion Chinese Yuan （CNY, 2000 constant prices）, i.e., 50.61% and 49.38% of total cost, respectively; （2） Shiyan City would gain 0.23, 0.06 and 0.03 CNY/m3 in 2014–2020, 2021–2030, and 2031–2050, respectively.

Nutrient transport following water transfer through the world's largest water diversion channel

Nutrient levels in the artificial channel constructed for the Middle Route Project are significant indicators of water quality safety and aquatic ecological integrity for this large,interbasin scheme.However,the distribution and transport of nutrients along the channel were poorly understood.Based on a time-series dataset as well as mass balance and material flow analysis methods,the water and nutrient transport fluxes in the Middle Route of the South-to-North Water Diversion Project were identified in this study.The results indicate that the nutrient concentrations varied considerably with time,but there was no significant difference among the 30 stations of the main channel.Seasonal temperature difference was the major factor in the large fluctuations of water quality indicators over time.The nutrient loadings varied with the water volume outputs from the main channel to the waterreceiving cities.Atmospheric deposition was an important source of nutrients in the main channel,accounting for 9.13%,20.6%,and 0.635%of the nitrogen,phosphorus,and sulfur input from the Danjiangkou Reservoir,respectively.In 2021,a net accumulation of 988 tons of N,29 tons of P,and 2,540 tons of S,respectively,were present in the main channel.The increase of these external and internal nutrient loadings would cause water quality fluctuation and deterioration in some local sections of the main channel.Our study quantified the spatial and temporal patterns of nutrient transport in the Middle Route and revealed the ecological effects on the aquatic environment,assisting authorities on the project to develop effective water conservation strategies.

南水北调西线工程水源区可调水量“十问”

南水北调西线工程是我国“四横三纵”国家水网主骨架尚待建设的最后一环,而水源区可调水量是西线工程规划论证面临的焦点和难点问题。本文从水资源本底条件与演变趋势,生态环境与经济社会发展需水,调蓄水库与输水工程规模,调水对水源区及其下游水资源开发利用、水生态环境、水力发电、航运等方面影响的角度,提出了与水源区可调水量相关的10个问题;以长江上游分布式水文模型为基础,建立了南水北调西线工程水源区可调水量模拟分析模型,力图系统、定量地回答所提问题。本文的主要研究结论有:在仅考虑满足水源区河道内外生态环境和经济社会需水的前提下,“上线+下线”组合方案多年平均可调水量为1.59×10^(10)m^(3),“完全下线”方案在建设岗托水库进行联调时,多年平均可调水量将达到1.74×10^(10)m^(3);在综合考虑调水对水源区水平衡、水力发电和航运影响及其可接受程度后,南水北调西线水源区可调水量为1.22×10^(10)~1.26×10^(10)m^(3)。长远来看,应谋划西南片区水网与国家水网主骨架、“大动脉”的连接与融合,在减小南水北调西线工程调水影响的同时,提高南水北调西线工程的整体供水能力以及对气候变化等外部条件的适应性。

南水北调中线水源区植被指数时空变化分析

通过单线性回归(SLOPE)和地理加权回归(GWR)法,用植被指数(NDVI)研究南水北调中线水源区的植被分布变化趋势及机制,为保障水量和水质提供理论支撑。结果表明,2000—2019年水源区NDVI和入库流量呈现同步增长,植被逐渐变好,2007年以前NDVI增长幅度大,2008—2011年处于波动阶段,2012年以后增长幅度减小;NDVI变化最明显的是研究区东北部、西部和丹江口库区周边,这些区域地势相对低平、人口集中,中山和高山区NDVI变化不大;高程、坡度、人口数和城镇化是影响水源区NDVI分布的主要因素,降水、气温和产业比重是次要因素;各因素影响的强度和方向在空间上有异质性,自然地理因素对NDVI影响的最显著范围为高程1090 m以下、年均降水量980 mm以上的区域,人文地理因素影响的显著范围区是人口密度大、城镇化率高的地区。

Simulation of Transport Channel in China's Middle Route South-to-North Water Transfer Project

The unsteady flow in the Middle Route South-to-North Water Transfer Channel was simulated numerically using an implicit solution procedure for the Saint Venant equations. An equivalent roughness was used to simulate the effect of many transfer structures on the water levels in the main channel. Various gate operating and control methods were analyzed to study the response to disturbances produced by varying the flow rates through the Tianjin outlet. The results show that when the inflow at the head changes in the same way as the sum of the flow rates through all the outlets, the transition time and the fluctuation of the water levels using the timed gate operation method are less than when using the simultaneous gate operation method, but the variations of the gate openings and flow rates through each control gate are much larger. The flow disturbances produced by the Tianjin outlet can be rectified within several channel sections and the transition time can be greatly shortened by allowing the water levels immediately upstream of the control gates to vary within proscribed ranges, rather than being held constant.

南水北调西线工程上线水源区大型底栖动物群落结构及环境驱动因子

为评估南水北调西线工程上线水源区大型底栖动物群落结构及环境驱动因子,于2022年7月(汛期)和11月(非汛期)开展监测采样工作。采用生物多样性指数和丰度-生物量比较曲线(ABC曲线)作为大型底栖动物群落特征参数,分析大型底栖动物群落在水源区的结构,并对其进行多元排序和Pearson相关性分析。结果表明:共采集45种大型底栖动物,隶属于4门5纲10目32科44属,其中优势种8种,所有优势物种出现频率均大于50%,水源区大型底栖动物群落结构一致性较高;水源区Margalef丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数均值分别为4.01、1.68、0.61;多数采样区域大型底栖动物的ABC曲线呈纠缠态势,其丰度和生物量累积百分比的差值面积在0附近波动,群落以小个头物种为主;优势种以耐污值低的敏感种类为主,说明河流几乎不受污染,水体清洁;pH值是影响水源区大型底栖动物群落结构的主要环境驱动因子。

高雷诺数下倒虹吸闸墩绕流水力特性

为研究倒虹吸出口闸墩绕流特性,以南水北调某典型倒虹吸为例,基于Flow3D软件建立倒虹吸模型,根据现场原型实测水位、流速进行模型验证;利用该模型模拟了雷诺数6.17×10^(6)~9.38×10^(6)范围下闸墩绕流特性。结果表明,高雷诺数条件下,随着雷诺数的增加,闸墩绕流造成的液面波动幅度增加,中墩液面波动显著大于边墩;闸墩后的尾涡量持续增加,雷诺数对斯特劳哈尔数影响不大;边侧闸墩受力的非对称性明显,边墩闸室间特征流速偏流比存在先增大再减小的变化规律,偏流效应造成的离心距不断增加。本研究可针对性改善输水工程水流流态。

南水北调东线江苏段典型泵站运行效率模拟模型

泵站机组运行受多种因素影响,导致泵站运行理论效率与实际效率误差较大。针对泵站机组运行效率精准模拟难题,运用基于高价多项式回归、回归树、多元线性回归、向量机回归、高斯过程回归、神经网络的10个回归算法,建立泵站机组效率模拟模型并开展对比分析,优选出有效的泵站运行效率模拟建模方法。讨论分析采用“上下游水位+流量”代替传统“扬程+流量”开展泵站运行模拟的效果。以南水北调东线邳州站和遂宁二站共8台机组的历史数据开展实例分析,相关实验结果表明:在所有方法中,高斯过程回归(Gaussian process regression,GPR)模型在均方根误差(ERMS)、平均绝对误差(EMA)、均方误差(EMS)、决定系数(R2)和最大个体误差(EMI)指标上综合表现最佳,R2逼近0.95;使用站上、站下水位代替传统的扬程对模型进行训练,所有模型的综合评价指标整体有所改善。综合来看,使用GPR模型并使用上游、下游水位代替扬程进行模拟效率表现最好,以邳州站4号机为例,可将模拟效率的EMA和EMI分别从16.49%和20.40%减少至0.41%和2.30%,研究成果具有一定实际意义,可为我国调水工程泵站经济运行提供有力支撑。