Maintaining healthy rivers and lakes through water diversion from Yangtze River to Taihu Lake in Taihu Basin

On the basis of the Taihu water resources assessment, an analysis of the importance and rationality of the water diversion from the Yangtz,e River to Taihu Lake in solving the water problem and establishing a harmonious eco-environment in the Taihu Basin is performed. The water quantity and water quality conjunctive dispatching ＇decisi＂ofi-makifig support system, which ensures flood control, water supply and eco-aimed dispatching, is built by combining the water diversion with flood control dispatching and strengthening water resources monitoring and forecasting. With the practice and effect assessment, measures such as setting the -integrated basin management format, further developing water diversion and improving the hydraulic engineering projects system and water monitoring system are proposed in order to maintain healthy rivers and guarantee the development of the economy and society in the Taihu Basin.

A numerical study on water diversion ratio of the Changjiang(Yangtze)estuary in dry season

We studied the flood, ebb and tidal averaged along (net) water diversion ratio (WDR) during dry season in the Changjiang (Yangtze) estuary, China, along with the effects of northerly wind, river discharge, tide and their interactions on WDR using the improved version of three-dimensional numerical model ECOM. Using data for annual mean wind speed and river discharge during January, we determined that the flood, ebb, net WDR values in the North Branch of the estuary were 3.48%, 1.68%,-4.06% during spring tide, and 4.82%, 2.34%,-2.79% during neap tide, respectively. Negative net WDR values denote the transport of water from the North Branch into the South Branch. Using the same data, the corresponding ratios were 50.09%, 50.92%, 54.97%, and 52.33%, 50.15%, 43.86% in the North Channel and 38.56%, 44.78%, 103.96%, and 36.92%, 43.17%, 60.97% in the North Passage, respectively. When northerly wind speed increased, landward Ekman transport was enhanced in the North Branch, increasing the flood WDR, while the ebb WDR declined and the net WDR exhibited a significant decrease. Similarly, in the North Channel, the flood WDR is increased, the ebb WDR reduced, and the net WDR showed a marked decrease. In the North Passage, the flood WDR also increased while the ebb and net WDR declined. As the river discharge increased, the flood and ebb WDR of the North Branch increased slightly and the net WDR increased markedly. In the North Channel the flood and ebb WDR changed very slightly, while the net WDR declined during spring tides and increased during neap tides. The WDR in the North Passage changed slightly during flood and ebb tides while the net WDR showed a marked increase. The WDR values of different bifurcations and the responses to northerly wind, river discharge, and tide are discussed in comparison with variations in river topography, horizontal wind-induced circulation, and tidal-induced residual current.

Wet-Dry Runoff Correlation in Western Route of South-to-North Water Diversion Project,China

The Western Route of the South-to-North Water Diversion Project is an important trans-basin diversion project to transfer water from the upstream Yangtze River and its tributaries （water-exporting area）, to the upstream of the Yellow River （water- importing area）. The long-term hydrologieal data from 14 stream gauging stations in the Western Route area and techniques including the pre-whitening approach, non-parametric test, Bayes, law, variance analysis extrapolation, and Wavelet Analysis are applied to identify the streamflow eharacteristics and trends, streamflow time series cross-correlations, wetness-dryness encountering probability, and periodicities that occurred over the last 50 years. The results show that the water-exporting area, water- importing area, and the streteh downstream of the water-exporting have synehronization in high-low flow relationship, whereas they display non- synchronization in long-term evolution. This corresponds to the complicated and variable climate of the plateau region. There is no obvious increasing or decreasing trend in runoff at any gauging station. The best hydrological eompensation probability for rivers where water is diverted is about 25% to lO%, and those rivers influenced significantly by diversion are the Jinsha and Yalong rivers. Proper planning and design of compensation reservoirs for the water-exporting area and stretch downstream of the water- exporting area can increase the hydrological compensation possibility from water-exporting area to the water-importing area, and reduce the impact on the stretch of river downstream of the water- exporting area.

Engineering Strategies on Flood Control in Middle Reach of Yangtze River, China

Flood disaster has been a serious hidden danger since the ancient time. The essential cause for the fact that floods have not been eliminated for hundreds of years is that time honored strategies do not suit the cases of flood prevention. In the view of geological environmental analyses of flood formation and from the synthesis of experiences gained in flood control in the past hundreds of years, sluggish draining of flood, silt sedimentation in channel and building levee blindly constitute the main cause of intractable flood for a long time in the middle reach of the Yangtze River. Draining away silt and water is the only way to stamping out flood disaster. Opening up artificial waterways for flood diversion, draining away the silt of channel into the polders, and storing the flood water are important engineering measures for the flood control and damage reduction.

Increasing probability of concurrent drought between the water intake and receiving regions of the Hanjiang to Weihe River Water Diversion Project,China

Water diversion projects are an effective measure to mitigate water shortages in water-limited areas.Understanding the risk of such projects increasing concurrent drought between the water intake and receiving regions is essential for sustainable water management.This study calculates concurrent drought probability between the water intake and receiving regions of the Hanjiang to Weihe River Water Diversion Project using Standardized Precipitation Index and Copula functions.Results showed an increasing trend in drought probability across both the water intake and receiving regions from 2.67%and 8.38%to 12.47%and 14.18%,respectively,during 1969-2018.The return period of concurrent drought decreased from 111.11 to 13.05 years,indicating larger risk of simultaneous drought between the two regions.Projections from CMIP6 suggested that under the SSP 2-4.5 and 5-8.5 scenarios,concurrent drought probability would increase by 2.40%and 7.72%in 2019-2050 compared to that in 1969-1990,respectively.Although increases in precipitation during 2019-2050 could potentially alleviate drought conditions relative to those during 1991-2018,high precipitation variability adds to the uncertainty about future concurrent drought.These findings provide a basis for better understanding concurrent drought and its impact on water diversion projects in a changing climate,and facilitate the establishment of adaptation countermeasures to ensure sustainable water availability.

水网布局下黄河流域应对极端枯水的关键科学问题

变化环境下极端气象水文事件频发,长江、黄河面临同枯风险。在国家水网建设背景下,为提高长江、黄河同枯的极端不利情景下黄河流域水资源安全保障能力,本文分析了长江、黄河两大流域水资源安全面临的现实问题,识别了变化环境下大型流域枯水遭遇—水危机形成—跨流域调水潜力—多线路成网互济—极端枯水下水资源安全保障中亟需破解的关键科学问题,构建了水网布局下黄河流域应对极端枯水的总体研究框架,提出该领域重点研究方向包括:变化环境下长江、黄河极端枯水遭遇规律与空间变异机制,水危机风险多链路传导与复合影响定量评估,极端枯水下跨流域调水挖潜增供,长江和黄河跨流域联合调配与多线路互济精细化调控、极端枯水下流域水资源韧性提升优化调控等。

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。

不同营养水平调水对贡湖湾湖区水质及浮游藻类影响的模拟研究

为探究“引江济太”工程调水给受水湖区水体带来的生态效应,采用水生微宇宙模型进行为期11 d的室内模拟实验,以太湖贡湖湾湖区为受水水体,引入3组设定好的不同营养盐水平(贫营养水平O、中营养水平M、富营养水平E)的望虞河河水,研究在不同营养盐水平调水影响下,受水水体水生态环境的动态响应过程。结果表明:整个实验过程中,中营养和贫营养调水组的水体TN、NO_(3)^(-)-N、NH4_(+)-N、TP、SRP、TOC含量下降明显,富营养调水组影响效果较中营养和贫营养调水组差;调水提高了受水水体生态系统的多样性和均匀度水平,硅藻等非蓝藻细胞密度增加,蓝藻细胞生长受到竞争胁迫,中营养和贫营养调水的影响作用效果好于富营养水平。RDA分析结果表明,受水水体的pH、DO、SiO_(3)^(2-)-Si、TDS、NO_(3)^(-)-N、SRP是本实验水体影响藻类群落结构的主要环境驱动因子。

引江济淮工程(河南段)水资源调配系统设计与开发

为强化引江济淮工程(河南段)水资源统一调配,基于Spring Boot和Vue前后端分离开发的模式,利用天地图API、WebGL、Echarts等技术设计研发引江济淮工程(河南段)水资源调配系统。从设计思路、功能界面、关键技术3个角度论述系统设计思路和实现过程,从而实现地理信息服务、供需水预测、水资源优化配置、水资源优化调度等功能,实现水量分配可视化、运行调度智能化和跨流域调水管控一体化。系统测试结果表明:引江济淮工程(河南段)水资源调配系统的建立提高了受水区水资源精细化管理的水平,解决了引江济淮工程(河南段)跨流域调水的配置难题,为受水区水资源高效利用提供有效的技术支撑。

高海拔季节冻土区完全融化期土壤水分特征曲线适用性

以怒江源区那曲流域为例,基于4个试验场完全融化期(6—9月)的土壤体积含水量(0.15~0.51 cm^(3)/cm^(3))和土壤基质势数据(0~200 kPa)实测数据,选择Van Genuchten(VG)、Brooks-Corey(BC)和Campbell 3个模型进行拟合,以均方根误差ERMS和决定系数R2为评价指标,分析3个模型对高海拔季节冻土区不同土层和不同土壤质地的适用性。结果表明:从整体上看,VG模型(平均R2为0.992,平均ERMS为0.006 cm^(3)/cm^(3))的拟合效果优于BC模型(平均R2为0.972,平均ERMS为0.019 cm^(3)/cm/3)和Campbell模型(平均R2为0.984,平均ERMS为0.014 cm^(3)/cm^(3));但是在不同土层和不同土壤质地情况下模型的适用性有所区别,VG模型更适用于壤土和壤质砂土(平均R2为0.987,平均ERMS为0.008 cm^(3)/cm^(3))以及土壤深层(10~35 cm土层,平均R2为0.990,平均ERMS为0.007 cm^(3)/cm^(3)),Campbell模型更适用于砂质壤土(平均R2为0.985,平均ERMS为0.009 cm^(3)/cm^(3))以及土壤表层(5 cm土层,平均R2为0.993,平均ERMS为0.006 cm^(3)/cm^(3)),BC模型在不同条件下都不是最优模型;参数θr取值大小会显著影响土壤水分特征曲线的形状。本研究可为深入研究高海拔季节冻土区的土壤水分运动特性以及中华水塔区的水源涵养作用提供支持。

调水工程建设期安全-进度-投资系统风险分析——以引江济淮工程(河南段)为例

以引江济淮工程(河南段)为例,在确定安全-进度-投资系统风险评价指标体系的基础上,基于层次分析-模糊综合评价方法分析安全、进度、投资的单项风险;在考虑工程建设期安全、进度、投资的相互影响后,基于改进的综合风险评价方法分析安全-进度-投资系统风险。结果表明:当分析单项风险时,安全、进度和投资风险的评价结果均为一般风险;当分析系统风险时,得到安全风险>进度风险>投资风险;进一步分析指标体系中的准则层和指标层,安全风险的现场风险中施工技术方案风险排序第一,是后续风险管控的重点。本研究为提高工程建设期安全-进度-投资系统风险的可靠性、降低风险事件的发生提出了理论和技术参考。

引江济淮工程(河南段)多目标水量优化调度

引江济淮工程(河南段)涉及河道、闸泵、管道和调蓄水库,约束条件复杂,常规的优化调度算法难以搜索可行解,求解效率低。选用受水区缺水率平均值最小、泵站总抽水量最小和受水区缺水率标准差最小作为目标函数,从供水保障、供水成本和公平性角度构建多目标水量优化调度模型。基于可行搜索思路,结合逆序演算和顺序演算过程对约束条件进行处理,引入决策系数,通过映射关系使搜索空间保持在可行域中,结合多目标非支配排序遗传算法(non-dominated sorting genetic algorithms,NSGA-II)进行求解,得到Pareto最优解集,并采用熵权法进行方案优选。结果表明,基于可行搜索的NSGA-II算法能够有效求解复杂调度系统的多目标优化问题,综合考虑多个目标的最优方案相对单目标方案更加合理,结果可为引江济淮工程(河南段)运行管理提供决策支撑。

咸潮影响下长江口水源地优化布局及白茆沙水库建设可行性分析

为提升远期上海原水水量、水质供应能力和应对突发咸潮入侵和水污染风险,在分析长江口水源现状和咸水入侵形势基础上,论证了长江口水源地优化布局的必要性,结合咸水入侵监测数据及反演成果提出在白茆沙新建水库方案及原水系统优化调度方案,并分析了白茆沙水库建设对河势变化、行洪、通航、渔业资源及生态环境等方面的影响。结果表明:在白茆沙新建水库是较可行的方案,可对上海境内的长江口水源地进行优化布局,扩大供水规模并上移取水口;拟建的白茆沙水库位于白茆沙整治工程内侧,既可确保围堤安全稳定,也不影响行洪、通航,对河势变化、渔业资源及生态环境影响微小;布置于水库南侧微弯水道处的取水口,既可避免淤积对取水口的影响,也可避免北支咸潮倒灌的影响;上岸后的输水管与崇明岛原水复线共建,增强了崇明岛原水的供水安全,与现有长江口和黄浦江水源地的原水系统互联互通,可实现上海原水系统“双源供水、一网调度”的目标。

长江苏州段水质变化及七浦塘引水对阳澄湖水质影响分析

根据2019—2022年长江苏州段水质各指标数据,分析变化趋势。结果表明,全年7月份的水质质量最差,超标主要项目为氨氮和溶解氧;夏季的水质较其他季节稍差,超标主要项目为溶解氧;2022年水质较前几年好转,Ⅱ类水断面占比上升,不达标月份减少,测次达标率集中在90%以上。溶解氧、总磷、总氮呈明显的季节性变化规律,溶解氧和总氮的含量冬春较高,夏秋较低;总磷变化规律则相反,冬春较低,夏秋较高。七浦塘引水工程对周边地区水质改善明显,七浦塘与阳澄湖引水期溶解氧、氨氮和总磷均显著优于排水期。

南水北调中线供水区水域面积变化遥感分析

为更好地研究调水对供水区域水域面积的影响,利用遥感技术研究了南水北调中线工程调水前后供水区及其下游四季的水域面积变化情况及其动因。研究表明:在调水工程实施之后,汉江中下游区域出现了水域面积大幅度下降的情况,汉江流域水域面积从2011年到2015年整体减少,尤其是春夏季水域面积减少最多,春季减少52.6km^(2),夏季减少65.8km^(2),减少比例达到17.3%,秋季和冬季水域面积减少幅度较小,秋季水域面积减少23.4km^(2),冬季水域面积减少最少,为4.2km^(2)。

突发水污染事件风险分析——以引江济淮工程(河南段)为例

从交通事故风险、污水排入风险以及其他风险等方面识别引江济淮工程(河南段)突发水污染事件的风险源,建立适应性的风险评价指标体系、指标等级划分标准和风险等级评价模型,综合评估7个评价河段突发水污染事件风险等级。结果表明:2个评价河段的风险等级为重大(Ⅱ级),5个评价河段的风险等级为较大(Ⅲ级)。从降低风险源危险性、提高风险控制有效性等方面提出突发水污染事件风险管控对策措施。本研究为降低引江济淮工程(河南段)突发水污染事件的发生概率和危害程度提供了支撑,对发挥工程综合效益、保障受水区供水安全、维护良好的水生态环境具有重要意义。

动态设计在引江济淮航标配布工程项目管理中的应用

以引江济淮航标配布EPC工程项目为背景,针对航标配布工程项目管理中的技术难点,通过结合动态设计及其机理,提出经施工现场反馈多方联动核实后动态调整设计方案,及时解决施工工程中出现的各类问题,从而达到提升工程质量、缩短工期、节约投资的目的,为EPC项目管理在航标工程领域的应用提供参考。

引江补汉工程实施对汉江航道通航条件的影响

针对引江补汉工程实施后丹江口—黄家港断面最小通航流量减少而引起水位下降的问题,进行了汉江丹江口—黄家港河段的综合整治工程研究。采用平面二维水流数学模型对工程河段综合整治工程实施前后的航道通航水流条件进行模拟对比分析。结果表明,实施综合整治工程可有效改善通航水流条件,解决了因最小通航流量减少、水位下降导致局部河段通航标准降低的难题,可为南水北调引江补汉工程实施提供技术支撑。

安徽省引江济淮二期工程对沿线自然公园生态及景观的影响分析

引江济淮工程是我国水利建设的标志性调水工程。引江济淮二期工程经过淮河以北的8个自然公园,对沿线自然公园的扰动和影响不可避免。根据工程影响区的生态及景观现状的系统调查,分析和预测该工程对沿线的生态及景观影响程度,探讨减轻该工程在自然公园生态及景观方面产生负面影响的思路和方法,提出优化工程方案、建立常态化生物多样性监测、用本土植物进行栖息地生态恢复等措施。安徽引江济淮二期工程对沿线涉及的自然公园生态和景观影响程度为“中低度影响”,通过施工阶段和运行期生态保护手段和栖息地恢复措施可有效解决问题。

倾斜钻孔揭露地质信息投影计算方法应用研究

为探索倾斜钻孔的应用,以克服钻探施工环境限制,通过对任意方位角和倾角的倾斜钻孔与所需地质剖面空间关系的研究,提出一种把倾斜钻孔揭露的地质信息准确投影到所需地质剖面上的方法。在倾斜钻孔的倾斜方向与所需地质剖面走向不一致的条件下,通过对倾斜钻孔揭露地质信息的起始和终止位置进行投影换算,进而得到符合实际地质特征的剖面。将所提出的方法应用于南水北调中线引江补汉工程勘察实践中,结果表明:该方法能够有效利用倾斜钻孔揭露信息;应用此方法进行倾斜钻孔勘探,不仅可以克服地表复杂的钻探施工环境,而且可以有效减少钻探进尺、提高勘察效率、节约勘察成本。