Natural Disasters of the Lower Reaches of Yellow River during the Longshan Period——The Natural Background of Dayu's Flood Control

It is very important to study the archaeological culture and origin of civilization in ancient China.The changes of the channels in the lower reaches of the Yellow River in the prehistoric period are part of the natural environmental background of the development of the ancient civilization in that area to be explored.This paper presents a series of legends,indications,scientific evidence,and macroscopic geographical background information of the evolution in the lower reaches of the Yellow River during the Longshan period.At first the river flowed from Northern Henan and Hebei to southwestern Shandong Province and Northern Anhui–Jiangsu provinces,and the mainstream of the Yellow River changed from the southeast to return to the north and flowed into the Bohai Sea in the late Longshan Period.During this period,floods were frequent.Various ethnic groups in the northern China plains suffered natural disasters and made great migrations which also contributed to the ethnic exchanges and integration.The people of the Central Plains made more dynamic adjustments in the relationship between mankind and the land by primitively escaping from the water and self–defensively controlling the rivers then to maintaining the local ecological environment by large–scale flood control measures,which promoted the settlement of Shandong,Henan,Jiangsu and Anhui provinces,the urban cultural development,and social evolution.Based on these events,the culture symbol of Dayu's Flood Control could be formed.

DEEP THOUGHTS OF LAND UTILIZATION ABOUT THE RARELY SEVERE FLOODING DISASTERALONG THE MIDDLE AND LOWER REACHES OF THE CHANGJIANG RIVER IN 1998

In the summer of 1998, a rarely severe flooding disaster occurred in the whole basin of the Changjiang(Yangtze) River, which caused enormous losses. By 22nd of August, 29 provinces, autonomous regions and municipalitieswere involved, 21. 2 million ha of land were inundated, 223 million people were affected, 3004 people were killed and4. 97 million buildings were collapsed. The estimated direct loss of the country accounted to 166. 6 billion yuan (RMB).The main reason of the disaster is the unusual climate but the unreasonable land utilization the aggravated the disaster.This paper consists of two parts. One part analysed the unreasonable land utilization, including the neglect of forest landprotection, which caused the forest land area to decrease by 440 thousand ha in the whole country every year, the enclosing of lakes for cultivation, which decreased the area of lakes located along the banks of the Changjiang River from 17 200km2 at the beginning of the founding of the People’s Republic of China to 6531 km2 in 1983, the changing of functions oflakes, which reduced the volume of storage exceedingly, for example, only 5 spots of lakes were used for storing water inWuhan City, and the slow progress of the construction of flood diversion and storage area, which would cause huge lossesonce flood was diverted. The other part explored the strategy of land utilization on the supplying of land for flood controlprojects, such as embankment, drainage installation, flood diversion and storage area, and on tapping the potentialsthrough narrowing and amalgamgting the range of rural residential quarters and small towns, reclaiming reserved resources, transforming middle and low productive fields, attaching importance to land arrangement and recultivation, and adjusting contracted fields partially, to ensure the sustainable and stable growth of the region.

Flood and Waterlogging Disaster Damage Evaluation in Middle-Lower Yangtze River by 3S technology

The evaluation method, model and process for the flood and waterlogging disaster condition by GIS,RS and GPS technology and the method for setting up disaster condition database, dyke database and historical disaster damage database are presented. An index of flood damage degree(FDD) used to evaluate the relative degree of disaster loss and divide flood and waterlogging area is suggested. The value of flood damage degree can be calculated as follows :taking the various disaster losses of sample area in a base year as standard value and computing the ratios of various disaster loss values in different areas and years to the standard flood disaster loss values, then summing up the weighted ratios. The computed results are the value of flood damage degree in the every year. The macroscopic flood disaster distribution can be evaluated by the values of flood loss degree.

北江流域“2022·6·22”暴雨洪水分析

2022年6月19日,北江流域发生“2022年第2号洪水”,为1915年以来最大的洪水。为提高对北江流域暴雨洪水特性的认识,采用定性与定量相结合的方法对该场洪水的雨水工情进行研究。分析暴雨中心、洪水量级、洪水传播时间等特征,并与历史暴雨洪水进行对比。借助种子蔓延算法比较“理想凑泄”和“经验控泄”调度方案的调控效果,同时考虑水库动库容效应进行调洪演算。结果表明:造成本次洪水灾害的主要原因是累计雨量大、降雨强度大以及暴雨区域集中;根据“理想凑泄”规则调度飞来峡水库取得了显著效果,但需要考虑水库动库容的影响。研究成果可为北江流域防洪减灾以及制定调度规则等提供支持。

长江安徽段江湖连通性及生物通道恢复研究

江湖阻隔是导致长江中下游江湖复合生态系统衰退的最主要原因,江湖连通和生物通道恢复是流域生态修复的重要措施之一。通过现场调查等方法研究了华阳河湖群、菜子湖、升金湖和安庆西江古道等与长江干流的阻隔现状及连通性特征,在此基础上探讨了技术和管理层面存在的问题并提出对策建议。结果发现:依托涉水工程建设开展恢复河湖生物通道的做法可以有效缓解江湖复合生态系统的衰退,尤其是以“过鱼设施建设、季节性灌江纳苗、生态水网建设”相结合的生物通道恢复方案具有技术可行性。相关成果可为长江中下游江湖连通性及生物通道恢复、国家水网建设提供有益的参考。

变化条件下长江下游地区防洪问题与韧性提升对策

长江下游地区圩区广布、城镇众多、水网稠密,汛期受长江上中游来水、长江口及沿海高潮和本地暴雨共同威胁。目前,该地区形成了以江河湖海堤防为基本屏障,以水库、湖泊和蓄滞洪区为洪涝调蓄空间,以长江及区域主要河道为洪涝行泄通道,各类闸站相配套的防洪治涝工程体系。但近年来长江流域大洪水事件表明,长江下游防洪工程薄弱环节仍然明显,蓄泄矛盾突出,空间统筹治理和工程协同调度不足,灾害风险预防管控存在盲区,同时还面临着气候水文和经济社会条件双重变化的复杂形势。为强化长江下游地区洪涝灾害风险集成调控、提升应对大洪水的韧性,需在稳固长江干流防洪屏障和行洪主通道的基础上,科学优化各水系洪涝蓄泄格局、加快补齐防洪基础设施短板、促进洪涝治理空间均衡协调、加强洪涝灾害风险管控预防、提升防洪管理智慧化水平。同时,还应针对长江下游地区重大防洪科技问题开展系统深入研究。

Efficiency of sediment transport by flood and its control in the Lower Yellow River

This paper presents the characteristics of sediment transport by flood in the Lower Yellow River with the reach from Huayuankou to Gaocun, which is regarded as a typical braided pattern. The Artificial Neural Network Model on Water Use for Sediment Transport (WUST) by flood was established based on the measured data from 1980 to 1998. Consequently, simulations of controlling process of sediment transport by flood were made in terms of the control theory under different scenarios. According to the situation of sediment transport by flood in the Lower Yellow River, Open-Loop control system and feedback control system were adopted in system design. In the Open-Loop control system, numerical simulations were made to reveal the relationship between average discharge of flood and the WUST with varying sediment concentrations. The results demonstrate that sediment concentration has significant influence on the controlling process of flood flow to WUST. It is practical and efficient to control WUST if sediment concentration is less than 20 kg/m3. In the feedback control system, controlling processes of sediment concentration and flood discharge for sediment transport were simulated respectively under given conditions, and it was found that sediment transport process could be controlled completely by sediment concentration and discharge at the inlet of the reach from Huayuankou to Gaocun. Using the same method, controlling processes of sediment transport by flood in other reaches in the Lower Yellow River were also simulated. For the case of sediment concentration being 20 kg/m3, the optimized controlling discharge ranges from 2390 to 2900 m3/s in the lower reach of Huayuankou. This study is also of significance to flood control and flushing sediment in the Lower Yellow River with proper operation modes of Xiaolangdi Reservoir.

Large-scale atmospheric singularities and summer long-cycle droughts-floods abrupt alternation in the middle and lower reaches of the Yangtze River

The daily precipitation data at 720 sta- tions over China for the 1957―2003 period during summer (May―August) are used to investigate the summer subseasonal long-cycle droughts-floods abrupt alternation (LDFA) phenomenon and a long-cycle droughts-floods abrupt alternation index (LDFAI) in the middle and lower reaches of the Yangtze River (MLYRV) is defined to quantify this phenomenon. The large-scale atmospheric circula- tion features in the anomalous LDFA years are ex- amined statistically. Results demonstrate that the summer droughts-to-floods (DTF) in the MLYRV usually accompany with the more southward western Pacific subtropical high (WPSH), negative vorticity, strong divergence, descending movements develop- ing and the weak moisture transport in the low level, the more southward position of the South Asia high (SAH) and the westerly jets in the high level during May―June, but during July―August it is in the other way, northward shift of the WPSH, positive vorticity, strong convergence, ascending movements and strong moisture transport in the low level, and the northward shift of the SAH and the westerly jets in the high level. While for the summer floods-to-droughts (FTD) in the MLYRV it often goes with the active coldair mass from the high latitude, positive vorticity, strong convergence, ascending movement develop- ing and the strong moisture transport in the low level, and the SAH over the Tibetan Plateau in the high level, but during July―August it is often connected with the negative vorticity, strong divergence, de- scending movements developing and the weak moisture transport in the low level, the remarkable northward shift of the WPSH, the SAH extending northeastward to North China and the easterly jets prevailing in the high level over the MLYRV. In addi- tion, the summer LDFA in the MLYRV is of significant relationship with the Southern Hemisphere annual mode and the Northern Hemisphere annual mode in the preceding February, which offers some predictive signals for the summer LDFA forecasting in the MLYRV.

广东省北江流域防洪体系与布局优化

结合广东省水网建设规划中的“江河安澜防洪保安网”,重点针对北江流域“22·6”特大洪水暴露出的现状防洪体系与布局的短板、弱项,在分析评估北江流域(思贤滘以上)现状防洪体系与布局的基础上,结合设计水文计算成果及骨干水库调洪计算、飞来峡水利枢纽动态库容调洪计算等分析成果,提出了“防、管、控”三位一体系统治理的北江流域防洪(潮)治理思路及“调蓄、拦挡、蓄滞、分洪、畅泄”多功能、有韧性、相融合的防洪体系与布局。按照治理思路和科学构建现代化水网目标,综合提出了完善、优化北江流域防洪体系与布局的各项具体工程和非工程措施。

金沙江下游梯级联合调度对川渝河段防洪效果评价

金沙江下游四级梯级水库联合调度为长江川渝河段提供了防洪安全保障,对其防洪调度效果进行评价,可以科学衡量与评估川渝河段防洪调度效果,促进流域洪水资源化利用。基于金下四级联合防洪调度方案,建立防洪、发电、生态和航运4个准则下的评价指标体系,采用改进的层次分析法和熵权法,构建川渝河段梯级水库防洪调度效果评价模型,综合考虑防洪和兴利效益,评估不同来水频率和不同起调水位的梯级水库防洪调度效果;对比溪-向两库联合调度与金下四级联合调度效果,分析乌东德、白鹤滩水库建成投产对于川渝河段防洪调度及洪水资源化利用的综合效果。结果表明:①随着乌-白两库起调水位升高,金下四级防洪调度效果系数呈现先升高后降低的趋势。②对于20,30,50 a一遇和100 a一遇洪水,乌东德和白鹤滩水库分别从(965 m和795 m)、(975 m和790 m)、(955 m和790 m)、(952 m和795 m)起调时,金下四级防洪调度效果系数最大,梯级水库联合防洪调度方案最优。③乌东德、白鹤滩水库建成投产后,川渝河段洪水资源化利用效果提升。研究成果可用于多功能、多保护对象的梯级水库防洪调度效果评价,为地区防洪调度决策提供依据。

三峡水库对城陵矶防洪补偿控制水位研究Ⅰ——需求分析与优化条件

城陵矶地区是长江中下游洪灾最频发的区域之一,是长江水库群防洪的重点保护对象。金沙江下游乌东德、白鹤滩、溪洛渡、向家坝4座梯级水库与三峡水库组成的巨型水库群防洪能力巨大,显著改变了流域防洪调度格局。在概括分析城陵矶地区防洪需求,回顾三峡水库对城陵矶地区防洪补偿控制水位不同阶段成果的基础上,剖析了优化防洪补偿控制水位的研究要点,研究了金沙江下游梯级防洪库容投入情况,进而明确了提高防洪补偿控制水位的有利条件。研究结果表明:在三峡水库水位达到城陵矶防洪补偿控制水位158.00 m后,金沙江下游梯级水库在预留40.93亿m^(3)防洪库容的基础上,尚有30亿~60亿m^(3)富余防洪库容可配合运用,为进一步提高三峡水库对城陵矶防洪补偿控制水位创造了良好条件。

上海市洪涝灾害损失对长江下游地区的辐射影响

随着区域经济一体化程度的加深,跨区域产业关联损失已成为灾害损失评估不容忽视的一部分,准确量化洪涝灾害损失的辐射影响对于制定防灾减灾措施、减少洪涝灾害损失具有重要作用。在系统评估了不同暴雨重现期情景下上海市减停产损失的基础上,采用两区域投入产出模型,测算和分析了长江下游地区不同省(直辖市)的区域内乘数效应、区域间溢出效应和区域间反馈效应,量化了上海市洪涝灾害损失对长江下游地区的辐射影响。结果表明,暴雨重现期10 a、20 a、30 a、50 a、100 a时,上海市的减停产损失分别为14.01亿元、19.83亿元、25.58亿元、33.82亿元和46.24亿元;在长江下游地区,上海市与浙江省的经济相互影响强度最大,且跨区域产业关联损失以溢出效应为主导;上海市发生洪涝灾害时,跨区域波及效应将导致长江下游地区损失增加26.24%。因此,在城市之间联系日益紧密的情况下,不仅要关注洪涝灾害对自身的影响,同时也要采取有效措施减少地域之间的波及影响,以便更有效地开展防灾减灾工作。

金沙江下游-三峡梯级水库2023年联合调度实践

金沙江下游-三峡梯级水库是治理和保护长江的关键性工程。为了进一步提高梯级水库应对持续枯水的能力,保障水资源综合利用效益全面发挥,结合2023年长江上游水雨情特点,全面分析了梯级水库应对持续枯水所实施的联合补水、汛期水位动态控制、联合蓄水等优化调度措施,总结提炼了梯级水库联合调度的成效和经验。实践结果表明:枯水期梯级水库累计向下游补水约243亿m^(3),有效保障了长江中下游供水安全以及航运、生态等综合效益;通过汛期抬水位、蓄水期精细化预报调度,有效提升了水资源利用效率,保障了梯级水库实现蓄满目标。提出的调度措施和经验可为今后流域控制性水库群联合调度方式优化提供重要参考。

三峡水库对城陵矶防洪补偿控制水位研究Ⅱ——风险分析与运用方案

乌东德、白鹤滩水库投运后,长江上游水库群联合防洪调度为进一步提高三峡水库对城陵矶防洪补偿控制水位创造了有利条件。为提高三峡水库对城陵矶防洪补偿控制水位,针对金沙江下游梯级防洪库容投入运用条件,基于三峡坝址不同典型年的不同频率设计洪水,开展了荆江防洪和库区回水风险分析,提出了金沙江下游梯级配合三峡水库的等比例分级拦蓄方式,在确保荆江及库区防洪安全的前提下,提出了三峡水库对城陵矶防洪补偿控制水位优化运用方案,给出了金下梯级预留防洪库容与三峡水库对荆江防洪库容的等效关系。研究结果表明:提出的等比例分级拦蓄方式综合了拦量和削峰两种模式,有效利用了金下梯级防洪库容,调度效果最好;提出的水位优化运用方案具备较好的防洪减灾效果,丰富完善了长江上游水库群联合防洪调度方案,可进一步减少中下游超额洪量。研究成果可为长江水库群实际洪水调度提供技术支撑和决策参考。

金沙江下游梯级水库提前蓄水策略

随着长江上游水库群汛末集中蓄水问题日益突出,在确保防洪安全的前提下,提前抬升水库运行水位,有序衔接防洪与蓄水调度显得尤为重要。以金沙江下游乌东德、白鹤滩、溪洛渡、向家坝梯级水库为研究对象,选取发电量和水资源利用率为评价指标,探究汛期7—8月份梯级水库提前蓄水策略。研究结果表明:①平水(50%频率)、枯水(75%频率)和特枯(90%频率)来水条件下,乌东德、白鹤滩梯级水库应尽可能提前抬升运行水位,且优先抬升乌东德库水位。②7月份平水、8月份平水或枯水条件下,应优先将乌东德库水位抬升至960 m以上;7月份枯水、8月份平水或枯水条件下,应优先将乌东德库水位抬升至954 m以上。③不同来水条件下,溪洛渡水库应尽可能抬升库水位,但最高不超过585 m。

汉江中下游重要支流目标生态流量分期控制研究

为有效推进河湖生态流量保障体系建设,采用Qp法、Tennant法、近10 a最枯月法、频率曲线法等方法计算分析确定了汉江中下游重要支流控制断面基本生态流量,采用适配法确定各断面生态流量分月泄放目标。研究表明:(1)汉江中下游重要支流控制断面的基本生态流量为1.16~7.50 m^(3)/s,占年均流量的5%~15%。除南河谷城断面受金盆沟电站发电引水导致满足度偏低外,其他断面满足度均高于90%,可作为生态流量管控依据。(2)各断面生存流量分月控制目标为1.16~55.00 m^(3)/s,年泄放量占年均径流量的20%,月均满足度可达80%以上。研究成果可为健全法规体系、强化工程生态调度、汉江流域水资源保护及监督管理提供参考依据。

黄河宁蒙河段凌情灾害成因分析及防御措施研究

随着经济社会的高速发展,对黄河的防凌安全提出了更高的要求,研究凌情灾害成因及防御措施变化显得尤为重要。通过分析,影响宁蒙河段凌情变化的因素主要包括热力条件、水动力条件和河道边界条件。通过梳理1989年以来宁蒙河段典型凌灾情况,发现造成冰凌灾害的严重凌情多受剧烈天气过程、河道流量变化、复杂河道条件等因素影响。为避免宁蒙河段凌汛灾害,针对热力因素,应及早开展凌汛期气温凌情预报工作;针对水动力因素,应优化凌汛期水库群和分凌工程联合调度;针对河道边界条件,应提前拆除临时阻水建筑物,保证河道畅通,协调空军部队在险情发生时及时轰炸破冰,并加快黑山峡水利枢纽建设,恢复和长期维持较大的中水河槽过流能力,为宁蒙河段防凌防洪提供基本条件。

陇海铁路伊洛河桥改建工程与防洪的探讨

伊洛河作为黄河重要支流,历来灾害频发,而陇海铁路伊洛河桥处于伊洛河泄洪卡口处,对偃师夹滩地区防洪安全造成严重威胁。通过对区域防洪形势及陇海铁路伊洛河桥现状问题进行分析,结合规划、既有铁路现状、设计时速、征拆等因素,提出陇海铁路改线新建铁路桥的方案,并对桥梁建成后与黄河下游防洪的相互关系进行分析,提出应在协调好伊洛河流域和黄河下游防洪关系的基础上再行开展改建工程,对下一步工作的开展提供了有益参考。

Large and meso-α scale characteristics of intense rainfall in the mid- and lower reaches of the Yangtze River

Meteorological conditions associated with intense rainfall and great floods over mid- and lower reaches of Yangtze River are studied by analyzing the large-, synoptic-and meso-a-scale circulation systems for 1991, 1996 and 1998. It is found that the advance and retreat of subtropical high over the West Pacific, the monsoon moisture surge from the South China Sea, cold air outbreak over mid- and high-latitudes, and the meso-α scale systems (250-2500 km) from the Tibetan Pleateau as well, are responsible for intense rainfall over the Yangtze River Valley. The persistent and heavy rains and great floods over the Yangtze River Valley occurred when all these four systems are synergetic or in phase lock.

基于EOF和REOF的1470—1911年黄河中下游地区旱涝空间分布特征分析

基于通过历史文献资料重建的1470-1911年黄河中下游地区36个站点的历史旱涝等级序列和矢量化的历史地图,利用EOF、REOF方法分析旱涝灾害空间特征。EOF方法展开的结果表明:前4个模态累计方差贡献率为71.85%,主要表现为第一、二、四特征向量场呈经向带状分布,第三特征向量场呈纬向分布;第一特征向量场的空间分布均为正值,说明黄河中下游地区的旱涝变化具有一致性,但是其余各特征向量场之间特点差异明显,说明在不同背景场和影响条件下,旱涝变化还存在较多局域性特征;REOF展开的结果可将黄河中下游地区旱涝划分为5个典型的敏感气候分区,这为进一步研究该区旱涝变化的区域性特征奠定了基础。