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1.
要长江流域近150a间发生的1870、1931、1935、1954与1998年特大洪水灾害损失严重;长江洪水是我国的心腹之患.1990年以来,长江大洪水高频发生,达6次.长江洪水的发生,除湖泊蓄洪功能减弱等因素外,与全球变暖有关.20世纪90年代为近千年中全球最暖的年代,水循环加快,长江中下游夏季降水量为近120a最多的十年,高出1961-1990平均值112mm;而降雨集中和大暴雨降水事件的增加是洪水增加的主要原因.区域气候模式模拟在CO2倍增时,长江流域温度升高2.2℃,夏季降水增加10%-20%,气溶胶的增加可能使此值降低一些.考虑气候变暖可能促进潜在蒸发增加9%-15%的假定情景,计算在降水增加10%,蒸发增加9%条件下,最大洪峰流量在大通站将会达到8.4×104 m3/s左右,己超过1998年洪峰流量;汉口站7.9×104 m3/s,超过有记录以来所有的洪峰流量;而在宜昌站高达6.94×104 m3/s,超过自有实测记录以来的除1896年和1981年以外所有的洪峰流量.假定情景的最高值出现在降水增加20%,蒸发增加15%时,大通站流量将达到9.45×104 m3/s,超过该站近百年最大值,1954年的9.26×104 m3/s;宜昌站将出现7.82×104 m3/s流量,超过1882年以来所有实测记录值,但比1870年据洪痕推算的10.5×104 m3/s仍有逊色.未来气候若继续变暖,降水量增加将给长江洪水防御带来巨大的压力.但上述估算是粗糙的,有一定的不确定性,需在以后的研究中进一步改进.  相似文献   

2.
长江防洪是国家水安全的重要部分.2020年受持续强降雨影响,7月长江中下游沿线及洞庭湖、太湖水位长时间超警戒水位,太湖超保证水位,鄱阳湖湖区部分站点达到历史最高水位;8月长江上游岷江和嘉陵江发生特大洪水,重庆等沿江城市部分地区被淹,防汛压力和灾害损失大.社会舆论持续关注,并对三峡等水库调控提出一些质疑.文章从应对195...  相似文献   

3.
冯锐 《地震科学进展》2023,(11):547-560
《竹书纪年》记载了大禹建夏以前的地震活动和气候变化,考古研究证实了公元前21世纪和17世纪两次上古地震的真实性,还揭示了北半球“小冰期”对全球生态文明的重大影响。介绍了黄河中下游地区的地震活动特点,以及对黄河溃决的影响。大禹治水的真实性研究在深入,更加重视到地震原因。结合近年间青铜器遂公盨的重大发现,作者从地震堰塞坝和太行山前断裂上探讨了大禹治水的可能机制。最后,简介了近年间在地震考古方面的一些进展。  相似文献   

4.
选择长江三峡出口部位的红花套断面,对现代长江主流线相沉积、泛滥沉积与三万年前的洪水沉积物粒度进行比较,据粒径大于1mm的粗颗粒粒度分析,发现三万年前的大洪水水动力强度可能是近现代大洪水水动力强度的1.5倍左右.据粒径大于80mm的巨砾粒度分析,三万年前的长江大洪水底流水动力可能是近现代大洪水底流水动力强度的1.35倍左右.因此推测三万年前的长江大洪水比近现代洪水大得多.  相似文献   

5.
通过测量辽宁省鞍山-海城地区地震重点监测区地下水离子浓度和氢、氧同位素组成,讨论了该区地下水化学类型的时空变化及其成因。测量结果表明,取样点水温变化范围为11.0~97.0℃,水样的总固溶物(TDS)在197.89~829.99mg/L之间,水样分为8种化学类型。大部分水样的δD、δ18O值均沿中国东北地区大气降水线分布,少数有所偏离,表明该区的地下水主要接受大气降水的补给,并可能有深部水的供给。研究区Ca-HCO3和Ca·Mg-HCO3型水主要是岩石风化溶解和阳离子交换作用的结果;Ca-HCO3·Cl和Ca·Na-Cl·SO4型水主要受岩石风化溶解、阳离子交换作用、深部卤水混入或人类活动影响;Ca-HCO3·SO4和Ca-SO4·HCO3型水与岩石风化溶解以及深部流体混入有关;Na-SO4·HCO3和Na-HCO3·SO4型水主要是深部来源水体的混入造成的。采样期间研究区发生2次ML≥3.0地震,采样点在地震发生月份出现了明显的离子浓度异常变化;Na+、Mg2+、Ca2+、Cl-和SO42-浓度变化明显,对地震活动响应较灵敏。  相似文献   

6.
喇家遗址史前灾害与黄河大洪水无关   总被引:1,自引:0,他引:1  
在世界不同地区的古史传说中普遍有关于史前大洪水的记载,其对古代人类社会演化的影响是广受关注的热点问题.中国史前大洪水和大禹治水的传说由来已久,被认为与夏朝的建立有紧密关联,但缺乏确凿的科学依据支持.针对此问题,有学者提出公元前1 9 2 0年左右黄河上游官亭盆地的大地震导致其上游积石峡形成堰塞湖,其溃决导致黄河流域出现特大洪水,为中国古史传说提供了科学依据的新颖观点.本文通过对喇家遗址地震喷砂裹挟的骨骼测年,对地震、洪水等地质灾害遗迹和考古遗存的综合分析,以及对积石峡堰塞湖沉积测年工作的对比,认为多学科的证据并不支持上述观点,喇家遗址地震发生的时间不早于公元前1 8 0 0年,而积石峡堰塞湖在公元前3 6 0 0年已经消亡.积石峡堰塞湖的形成与溃决、喇家遗址古人类的突然死亡和古地震是不同时间独立发生的事件,不存在公元前1 9 2 0年左右黄河上游的特大洪水,将其与大禹治水和夏朝建立进行联系的基础是不成立的.  相似文献   

7.
地球自转速率变化与河道演变及泥沙灾害关系初探   总被引:1,自引:0,他引:1  
丰沙期及低频率、高强度洪水往往酿成泥沙灾害和洪涝灾害。地球自转变化是影响河道演变与诱发泥沙灾害的重要的自然因素,由长江、黄河及淮河的部分水沙资料及地球自转日长变化资料的初步分析表明,当地球自转由加速转向减速时,黄河下游出现枯水、少沙时期,长江中下游及淮河出现高频率、低强度洪水;而地球自转由减速转向加速时,黄河下游出现丰水期和中、丰沙期,长江与淮河出现低频率、高强度洪水,长江下游处于切滩旺盛期。在地球自转变化的转折点之间,河道处于相对稳定演变阶段,一般不会发生严重的洪涝与泥沙灾害。  相似文献   

8.
在巢湖西北半湖近岸带设置大型围隔研究秋季连续打捞蓝藻对湖泊温室气体通量的影响,应用YL-1000型大型仿生式水面蓝藻清除设备进行原位打捞蓝藻,通过便携式温室气体分析仪-静态箱法对大型围隔内水-气界面CH4、CO2通量特征及其影响因素进行观测.结果表明:对比未打捞区,蓝藻连续打捞下打捞区水体中叶绿素a(Chl.a)、悬浮物(SS)浓度不断下降,两者削减率分别为72%、85%,Chl.a、SS浓度分别下降到29.6±2.5 μg/L、12.5±1.2 mg/L,打捞对围隔内颗粒态物质去除效果十分明显;打捞过程中水体溶解性有机物(DOM)中微生物代谢类腐殖质(C1)、类蛋白(C3)显著下降趋势,打捞区C1、C3组分(0.18±0.02、0.06±0.01 RU)强度明显低于未打捞区(0.26±0.05、0.12±0.03 RU),打捞能有效控制藻源性溶解性有机质释放.同时,打捞区水-气界面CH4通量呈显著下降趋势,未打捞区CH4通量平均值(17.473±1.514 nmol/(m2·s))为打捞区(7.004±4.163 nmol/(m2·s))近2倍,CH4通量与Chl.a、C1、C3组分均呈显著正相关,水体中藻源性溶解态有机质对CH4通量具有促进作用;打捞区CO2释放通量呈显著上升趋势,打捞区CO2吸收通量(-0.200±0.069 μmol/(m2·s))明显低于未打捞区(-0.344±0.017 μmol/(m2·s)),CO2通量与Chl.a、温度均呈显著负相关.秋季打捞对CH4、CO2综合日平均通量减排量值为0.275±0.076 mol/(m2·d)(以CO2当量计).研究结果揭示了巢湖秋季连续打捞蓝藻过程对水-气界面温室气体具有显著减排作用,且能在一定程度上减缓蓝藻水华与湖泊富营养化、气候变暖之间的恶性循环,为湖泊碳循环和蓝藻水华灾害防控提供科学数据支撑和理论参考.  相似文献   

9.
长江中游通江湖泊江湖关系研究进展   总被引:27,自引:8,他引:19  
自然通江的洞庭湖和鄱阳湖与长江之间形成复杂的江湖水沙交换关系,其变化影响着区域洪水灾害防治、水资源利用、水环境保护和水生态安全维护,是长江中游水问题的核心.从长江中游大型通江湖泊江湖关系的概念与内涵、江湖关系演变过程、江湖关系变化的影响因素及效应等方面,系统梳理了长江中游通江湖泊江湖关系研究的进展.针对当前研究现状和存在的问题,提出了研究江湖关系表征指标体系是正确认识江湖关系的前提;定量区分人类活动和气候变化影响的贡献率是江湖关系研究的重点和难点;深入跟踪研究三峡等重大工程对江湖关系变化的影响是一项长期任务;评估江湖关系调整背景下江湖关系的健康状况,研究以江湖水系重大水利工程群联合调度为核心的江湖关系优化调控原理,维持江湖两利的长江中游健康河湖系统格局和相互作用关系是江湖关系研究的根本目标.  相似文献   

10.
模型估算法是水-气界面甲烷(CH4)通量监测的主要方法.本研究选择6种不同的参数化模型方法估算了2015年6、8和10月两个亚热带河口养殖塘水-气界面CH4传输速率(kx)及其扩散通量,探讨了河口养殖塘kx及CH4扩散通量的变化特征和影响因子.结果表明:研究期间,不同模型估算下的kx及其扩散通量均值在闽江河口养殖塘变化范围分别为1.60±0.75~6.29±1.30 cm/h和9.19±2.67~30.64±6.28 μmol/(m2·h),在九龙江河口养殖塘的变化范围分别为0.89±0.19~6.07±0.61 cm/h和3.18±0.48~21.03±2.13 μmol/(m2·h);kx及其扩散通量在两个河口区均呈现随时间推移而升高的特征;整个养殖期间,养殖塘水-气界面平均CH4传输速率kx呈现闽江河口略高于九龙江河口(P>0.05),但水-气界面平均CH4扩散通量呈现闽江河口显著高于九龙江河口的特征(P<0.05);风速、水体溶解CH4浓度和盐度是调控河口区养殖塘水-气界面CH4扩散通量变化的重要因子;不同模型估算出的河口养殖塘水-气界面CH4传输速率kx存在差异,表明模型估算法获得的水-气界面CH4扩散通量存在一定的不确定性.  相似文献   

11.
全新世高温期环境变化对太湖流域新石器文化的影响   总被引:9,自引:3,他引:6  
施少华 《湖泊科学》1993,5(2):136-143
从太湖流域新石器时代(包括马家浜、崧泽和良渚三个文化期)文化遗址的分布范围、遗址数量、生产方式和文化特征等多方面,分析了全新世高温期(8—3ka B.P.)环境变化对本地区新石器时期古文化发展的影响。结果表明,全新世高温期暖湿而且较为稳定的气候环境,有利于先民们的生活,促使了本地区新石器文化的飞跃发展,包括原始农业、家畜业的产生和发展,先民们活动范围扩大和遗址数量增加等等。但高温期中存在气候剧烈波动阶段和气候迅速变化的低温事件,以及伴随它们出现的各种严重自然灾害,严重阻碍和限制了古文化的发展,甚至是毁灭性的打击,使得文化性质发生根本的变化。  相似文献   

12.
Flood control of the Yangtze River is an important part of China’s national water security.In July 2020,due to continuous heavy rainfall,the water levels along the middle-lower reaches of the Yangtze River and major lakes constantly exceeded the warning levels,in which Taihu Lake exceeded its highest safety water level and some stations of Poyang Lake reached their highest water levels in its history.In August 2020,another huge flood occurred in the Minjiang River and the Jialing River in the upper Yangtze River,and some areas of Chongqing Municipality and other cities along the rivers were inundated,resulting in great pressure on flood control and high disaster losses.The 2020 Yangtze River flood has received extensive media coverage and raised concerns on the roles of the Three Gorges Dam and other large reservoirs in flood control.Here we analyze the changes in the pattern of the Yangtze River flood control by comparing the strategies to tackle the three heavy floods occurring in 1954,1998,and 2020.We propose that the overall strategy of the Yangtze River flood control in the new era should adhere to the principle of"Integration of storage and drainage over the entire Yangtze River Basin,with draining floods downstream as the first priority"by using both engineering and non-engineering measures.On the basis of embankments,the engineering measures should use the Three Gorges Dam and other large reservoirs as the major regulatory means,promote the construction of key flood detention areas,keep the floodways clear,and maintain the ecosystem services of wetlands and shoals.In terms of non-engineering measures,we should strengthen adaptive flood risk management under climate change,standardize the use of lands in flood detention areas,give space to floods,and promote the implementation of flood risk maps and flood insurance policies.The ultimate goal of this new flood control system is to enhance the adaptability to frequent floods and increase the resilience to extreme flood disasters.  相似文献   

13.
PREDICTIONOFIMPACTOFTHETHREEGORGESPROJECTONESTUARYBEACHOFTHEYANGTZERIVERWeibingFENG1YigangWANG2andXiuchengZHONG3ABSTRACTAltho...  相似文献   

14.
All around the world, ancient legends exist about the Great Flood, and the influence of the Great Flood in human evolutionary history is a hotly debated topic. In China, the legend of the prehistoric Great Flood and Yu the Great’s flood control has a long history and is considered to be closely linked to the establishment of the Xia Dynasty. However, there is a lack of solid scientific evidence. Against this issue, some scholars have proposed that an earthquake around 1920 BCE in the Guanting Basin along the upper reaches of the Yellow River led to the creation of a lake by damming in the Jishi Gorge and that the outburst of water from that lake led to the massive flood in the Yellow River region. These studies provided new scientific evidence for the Chinese legend. In this paper, we date skeletal samples embedded in earthquake sand blasting from the Lajia site, analyze remains from natural disasters (such as earthquakes and floods) and also archaeological remains. In addition, we compared the skeletal samples dating with that of sediments from the dammed-up lake. Our results are inconsistent with those of previous scholars. The earthquake at the Lajia site occurred no earlier than 1800 BCE, and the dammed-up lake in Jishi Gorge had disappeared by 3600 BCE. Thus, the formation and outburst of the dammed lake, the sudden death of ancient humans at the Lajia site and the ancient earthquake were independent events occurring at different times. In addition, the massive flood in the upper reaches of the Yellow River did not actually happen. Thus, we argue against and invalidate the hypothesis that the massive flood was related to Yu the Great’s flood control and the establishment of the Xia Dynasty.  相似文献   

15.
In this article,the shrinking of Dongting Lake and its progressively weakening connection with the Yangtze River and their impact on flooding before and after the implementation of the Three Gorges Project are analyzed.In recent decades,human activity combined with natural processes has altered the flow of the middle reach channel of the Yangtze River and interfered with its connection with Dongting Lake.This has resulted in progressively more frequent flooding in the area.This study uses hydrological data to analyze the annual maximum discharge and annual maximum stage development of the middle reach of the Yangtze River and Dongting Lake.In recent decades before the Three Gorges Project became operational in 2003,the annual maximum discharge and the maximum stage recorded in the middle reach of the river downstream of Dongting Lake had increased,a result of the weakening of the flood regulation function of Dongting Lake;the annual maximum stage at Luoshan station(downstream,close to the confluence of the Yangtze River and Dongting Lake) had risen by about 2.0 m during 1955-2005,(1.5 m attributed to annual maximum discharge and 0.5 m to river channel deposition).Observational data recorded after the Three Gorges Project was put into operation in 2003,it can be seen that deposition in the Dongting Lake has nearly ceased and the lake's connection with the Yangtze River is stable.It is evident that the flood regulation function of Dongting Lake will continue,and that during the lifetime of the Three Gorges Project,the flood situation in the middle reach of the Yangtze River and Dongting Lake will remain stable.  相似文献   

16.
远古时代京津唐地区一次大震的研究   总被引:5,自引:2,他引:5       下载免费PDF全文
本文介绍了京津唐地区内埋藏在全新世地层中的一次古地震遗迹和构造变形。通过对本区全新世地层、古环境的研究确定这次地震事件为距今4000年、本区海侵结束时发生的,恰恰与史料纪载的“地震传说”一致。文章最后对发震背景,砂基液化以及震中、震级等问题进行了一些讨论  相似文献   

17.
太湖流域水问题及对策探讨   总被引:1,自引:0,他引:1  
孙继昌 《湖泊科学》2005,17(4):289-293
系统回顾了太湖流域自古以来的治水历史和经验教训,详细介绍了新中国成立后太湖治理进展和取得成就,分析 了当前流域存在的主要水问题,指出流域仍存在防洪减灾能力偏低、水资源调控能力不足、水污染严重、水资源和水环境 承载能力偏低等问题.这些问题如不能得到及时解决,将成为今后流域经济社会可持续发展的严重制约因素.在此基础 上,提出了要加快构建流域防洪减灾体系、流域水资源调控体系、流域水生态环境保护体系、流域现代化管理和调度体系 等四大体系的对策,实现太湖流域水资源“引得进、蓄得住、排得出、可调控”的目标,以太湖流域水资源可持续利用支撑 和保障流域经济社会的可持续发展.  相似文献   

18.
In this paper the researches made in 1981-1990 have identified that the annual soil loss in the Three Gorges region is 157 million t. and the annual incoming sediment load of the Three Gorges reservoir is 40 million t. Soil erosion increases with the destruction of vegetative cover and its subsequent evolution. The annual amounts of sediment erosion for forest land, shrub land, grassland and farmland make up respectively 6.19%, 10.76%, 23.05% and 60% of the total erosion of the Three Gorges region; the quantities of incoming sediment load to the Yangtze River from the above four types of land account for 5.95%, 12.42%, 35.46% and 46.1 % of the total amount of sediment transported to the reservoir. The farmland of offers the main source of sediment. Gravitational erosion produces more bed loads, which will present serious threat to the Three Gorges Project if entering the reservoir. Resettlement of people to the upper parts of the mountainous areas for agricultural production will increase the sediment yield of the Three Gorges region by 10-20 million t and increase the incoming sediment of the Yangtze River by 50-60 million t. Consequently, it is necessary to make a realistic assessment of the soil erosion in the Three Gorges region.  相似文献   

19.
从古文化遗址看阳澄湖地区环境变迁与湖群形成   总被引:2,自引:0,他引:2  
倪华  吉磊 《湖泊科学》1997,9(1):35-40
通过阳澄湖地区新石器时代古遗址的时空分布特征,遗址地层中沉积特征和动植物遗存,来阐明7-4kaB.P.湖区环境由水域面积较广的湖沼环境,向陆域面积逐渐扩大的环境转变,直至新石器末期,被较大规模水侵淹没的过程,阳澄湖及周围湖荡主要形成于宋代,在原娄江河道基础上,河道阻塞,洪水泛滥扩展而成湖。  相似文献   

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