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.

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.

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.

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.

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.

气候变化对南水北调西线工程的影响及建议

南水北调工程是国家水网的重要组成部分,其西线工程建设是缓解我国西北、华北地区水资源短缺的重要举措。气候变化下西线工程引水区和受水区水资源情势直接关系到工程的规划建设与运行方式。基于历史实测资料和气候模式情景,采用数理统计与水文模拟相结合的途径分析了气候变化对南水北调西线工程引水区和受水区水资源的影响。结果表明:1)1961—2020年西线调水区和受水区气候变化以暖湿化为主要特征,调水区年径流量整体稳定略增,受水区年径流量显著性减少。2)未来中期(2035年)和远期(2050年),调水区和受水区气温继续显著升高,降水多呈非显著增加;未来中期、远期调水区年径流量较基准期(1961—2000年)分别增加1.42%和2.08%,受水区年径流量分别减少1.02%和0.28%。3)未来气候变化下,调水区年径流量相对稳定,能够满足调水需求,受水区年径流量略减,对跨流域调水需求有所增加。为确保南水北调西线工程的长期稳定运行,建议加强气候变化及其影响的不确定性研究,制定科学合理的应对措施,以应对未来可能的水资源短缺的挑战。

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.

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.

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。

基于多方法综合比较的南水北调西线工程水源区生态需水研究

针对南水北调西线工程调水需求,以方法比选、目标修正、可行性验证为主线,提出了一套多方法综合确定水源区生态需水过程的思路,并制定了10个坝址断面枯水期和非枯水期的生态基流、敏感生态需水及年生态水量目标。结果表明:水源区坝址断面枯水期生态基流在多年平均流量中的占比约为20%,非枯水期占比约为40%;3—6月为鱼类集中产卵敏感期,需要每月发生一次脉冲流量过程,每次至少持续10 d,脉冲流量在多年平均流量中的占比为48%~73%;各坝址断面年均生态水量在多年平均径流量中的占比约为70%,其中丰水年、一般偏枯年、枯水年生态水量占比分别为68%~78%、66%~75%和61%~70%;研究结果符合长江流域现有管控要求,具备较好的现实可达性。

南水北调西线工程水源区生态需水研究

可调水量一直是南水北调西线工程争论的焦点,水源区生态需水是合理确定西线工程可调水量的重要依据。分析了南水北调西线工程水源区的生态环境特征、主要生态环境保护对象,并针对西线工程水源区生态需水研究现状及存在问题提出了需要重点研究的关键科学问题:生态需水应统筹考虑川陕哲罗鲑等关键物种、河岸植被等优势群落、干旱河谷等典型生态系统,深入研究高寒脆弱区关键保护对象对水文过程的响应规律,以及协调节点-河段-河流廊道多尺度、物种-生境-生态系统多目标的生态流量需求核算。此外,提出了“识别特殊需求-建立响应关系-统筹核算水量”的生态需水研究思路,以及节约用水、科学研究、关键技术等方面的区域生态环境保护工作建议。

寻求南水北调西线项目的替代性方案

鉴于我国水资源南北区域分布不均衡,20世纪50年代开始党中央就提出南水北调工程。2002年,《南水北调工程总体规划》获得国务院批准,规划建设东线、中线、西线工程。目前中线、东线一期工程已经建成通水,南水北调后续工程是否为西线工程、西线工程何时开工为各方关注。但从工程安全性、经济合理性角度出发,南水北调西线工程都应放弃。取而代之的,把更多黄河之水用于中上游地区,增设中上游短距离引黄工程。与此同时,可增加南水北调中线、东线向北调水量,以满足黄河中上游用水增加时中下游的用水需求。除此而外,可以采取节水、节约粮食、海水淡化、南水南调、优化经济结构多种政策管理方式,进一步改善我国南北区域的用水需求。

南水北调西线工程总体布局及一期工程方案研究

南水北调西线工程从长江上游调水进入黄河上游,已研究70多a,历经多个研究阶段,形成调水方案数百个。经过深入论证,西线工程总体布局和工程规划方案已纳入2002年国务院批复的《南水北调工程总体规划》,并在2008年完成第一期工程项目建议书。2008年以来,随着西线工程前期研究工作的深入,结合新形势和新发展要求,其调水规模和调水线路研究已逐渐聚集,形成了上下线组合调水的总体布局方案和一期工程方案。一期工程的上线和下线是独立的调水线路,其中上线已经过数十年勘察论证,前期工作基础扎实,入黄位置高,覆盖范围广;下线利用在建工程作为水源水库,水源条件相对较好。一期工程已具备开展可行性研究的条件。建议国家尽早决策西线工程开工建设,补齐国家水网主骨架,为实现“让黄河成为造福人民的幸福河”和支撑西部发展提供有力水资源保障。

南水北调西线工程受水区缺水形势研究

黄河流域最大的矛盾是水资源短缺。从农业、工业和生态用水等方面识别流域现状缺水状况,考虑新形势下黄河流域水资源条件、黄河流域生态保护和高质量发展等重大国家战略要求,预测黄河流域2035年需水量约为545亿m^(3),缺水量约为136亿m^(3),其中上中游六省(区)缺水量约103亿m^(3),占比76%,是流域内缺水最严重的地区。南水北调西线工程是解决黄河流域缺水问题的根本措施,上中游六省(区)是主要受水区,一期工程调水80亿m^(3)可基本解决上中游六省(区)生活、工业等刚性用水需求。

南水北调西线工程受水区节水潜力研究

科学论证南水北调西线工程调水规模,需要以充分考虑黄河流域节水潜力为基础。以南水北调西线工程受水区为研究区域,分析了不同行业的节水现状、节水潜力及面临的问题。结果表明:黄河流域现状节水总体达到国内较高水平,但空间分布不均匀;黄河流域毛节水潜力约为25亿m^(3),净节水潜力约为19亿m^(3);西线工程受水区毛节水潜力约为21亿m^(3),净节水潜力约为16亿mm^(3);农业节水潜力占全流域及西线工程受水区节水潜力的80%以上;黄河流域节水潜力远低于缺水量,且农业节水量难以转让给其他行业;资源性缺水是根本问题,未来需要通过建设跨流域调水工程解决黄河流域缺水问题。

南水北调西线工程下线调水方案沿革及研究

70 a来南水北调西线工程历经了多个论证阶段。基于西线工程原规划方案及第一期工程项目建议书提出的上线调水方案(金—雅—大—贾联合调水方案)调水80亿m^(3),开展西线工程调水断面下移方案研究,初拟4个自流方案、2个抽水方案,6个调水断面下移方案均初拟调水量170亿m^(3)。经多因素综合比较,推荐叶巴滩—两河口—双江口—洮河联合自流方案作为西线工程调水断面下移方案(称为下线方案)。下线方案的水源水库均已通过中华人民共和国国家发展和改革委员会核准,水源条件相对较好,可为西线工程前期工作论证提供重要技术支撑。

南水北调西线工程上线调水方案沿革及研究

南水北调西线工程历经70余a论证,经历了多个论证阶段。2002年国务院批复的《南水北调工程总体规划》提出了调水170亿m^(3)的总体工程布局,2008年完成的《南水北调西线第一期工程项目建议书》(初稿)提出了调水80亿m^(3)的工程布局。随着论证工作不断深入,对工程方案的技术经济可行性以及对调水区生态的影响认识不断加深。结合新时期新要求,依托前期工作成果,对调水方案深化研究,深入分析调水河流河道内生态环境需水量,复核已有方案调水规模,优化调水方案,分析调水影响,提出了优化后的金沙江—雅砻江—大渡河—贾曲(上线)方案,即金沙江岗托水库抽水40亿m^(3)+雅砻江、大渡河调水40亿m^(3)的联合调水80亿m^(3)方案。

黄河上游西线调水工程对调出区气候影响的初步分析

在分析南水北调西线工程水量调出区气候特征的基础上,采用定性与定量相结合的方法,重点分析了调水工程对库区与坝址下游临近河段局地气候的影响,以及调水对引水坝址下游“干旱河谷”区的可能影响,并对干旱河谷的分布及其成因进行了较深入的分析。结果表明:调水对库区气候影响不大;对坝址下游临近地区的气温、降水等将不会造成明显的影响;对干旱河谷区的局地气候虽有影响,但很微弱。

黄河上游南水北调西线工程可调水量及风险分析

南水北调西线工程调水区水资源丰富,生态环境脆弱,当地社会经济用水量很少,生态环境用水是决定调水区可调水量的关键。论文综合分析了引水坝址下游河道生态环境用水,并将其作为主要约束条件,提出了南水北调西线工程可调水量。风险分析表明,该调水方案风险小,可靠性高,实施多库联合调度后,可进一步减少风险。

西线调水工程对水量调出区的环境影响分析

介绍了南水北调西线工程新的调水方案 ,工程所在位置及其影响所及的区域。在此基础上 ,从自然环境和社会环境两个方面 ,对南水北调西线工程水量调出区可能产生的主要环境影响问题进行了初步研究 ,包括调水对气候、动植物、水质、水库区及周边地质环境、人群健康等的影响 ,以及水库淹没对社会经济的影响等。其主要结论是 :1对库区、坝址临近地区的气温、降水影响均较小 ,由于库区水汽蒸发量增加对局地降水的贡献率约为 0 .0 0 4～ 0 .0 0 8;对干旱河谷区气候虽有影响 ,但很微弱。 2对生物会产生一定影响 ,主要表现在对渔类区系组成、种群结构等方面。对陆生生物造成一定数量的减少 ,但不会造成生物物种资源的减少。3坝址下游水质比现在有所下降 ,但由于河段所在位置人口密度低 ,污染较轻 ,对水质不会有大的影响。 4淹没损失小 ,移民少。本文可为西线调水工程对环境影响研究提供部分参考依据。