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1.
Variations in the regime of the Angara River flow fluctuations and in the components of the water balance of Lake Baikal are discussed. 相似文献
2.
The results of modeling of the long-term fluctuations in Lake Baikal levels and Angara River runoff are presented. The dynamic-stochastical model was developed and used to obtain analytical relationships between the statistic characteristics of the Baikal levels fluctuations and the parameters of forcing processes, including water inflow into the lake and the effective evaporation from its surface. The parameter λ determining the inertia of the Baikal levels fluctuations, decreased by about three times after Irkutsk Reservoir filling, resulting in an increase in the variance of the lake levels fluctuations. The dependence of variances of the Baikal levels fluctuations and Angara runoff on parameter λ was studied. It is shown that the decreasing in the variance of the Baikal levels fluctuations corresponds to increasing in the variance of Angara river runoff and vice versa. The results of numerical modeling of Baikal levels fluctuations show that water withdrawal from inflow into the lake has an adverse effect on Angara runoff regime. 相似文献
3.
V. E. Pavlov R. V. Veselovskiy A. V. Shatsillo Y. Gallet 《Izvestiya Physics of the Solid Earth》2012,48(4):297-305
We present new magnetostratigraphic results obtained from a well-dated Ordovician key section located along the Angara River,
near the terminus of the Rozhkova River (southern Siberian platform). More than 220 samples were thermally demagnetized up
to 670°C in order to isolate their characteristic ancient magnetization. Samples from the Arenig, the Llanvirn and the Llandeilo
stages are all (but two) of reversed magnetic polarity. In contrast, samples dated of the Caradoc yield a sequence of several
magnetic polarity intervals. These new data therefore confirm the occurrence of a long reversed magnetic polarity interval
during the Ordovician, the so-called Moyero superchron, which ended during the middle or late Llandeilo. 相似文献
4.
2018年金沙江上游白格滑坡造成了近百年来最为严重的干流堵江事件,堰塞湖的形成和溃决给下游金沙江干流河道的水沙条件及梯级水电站运行造成影响.本文依据堰塞湖附近临时观测和金沙江干流河道控制性水文站的相关资料,研究堰塞体泄流对下游河道水沙输移的影响,同时结合梯级水库调度情况,计算了梯级水库的拦沙量.结果表明,堰塞湖溃决在金沙江中游形成了超历史的水沙过程,金沙江中游梯级电站开展应急调度后,堰塞湖溃决造成的特大洪水被削减为一般洪水.金沙江中游梯级梨园、阿海和金安桥电站累积拦截泥沙约1400万t,龙开口、鲁地拉和观音岩电站共计拦截泥沙约43万t,滑坡体产生的泥沙仍有约74%滞留在堰塞体附近.若滑坡体泥沙全部输移至金沙江中游梯级水库内,梨园电站的有效库容极有可能不满足水库所需调节库容的要求. 相似文献
5.
The hydrological and morphological processes in the mouth area of the Upper Angara (which ranks second in terms of water abundance among Baikal Lake tributaries) are considered. The major external factors that determine those processes have been revealed. The main features of the delta??s water regime, including the effect of anthropogenic level rise in the lake, are described. Specific attention is paid to morphological processes in the delta and on the barrier bar, separating a large mouth lagoon from the lake. 相似文献
6.
Seismicity of the southern Siberian platform: Spatiotemporal characteristics and genesis 总被引：1，自引：0，他引：1
Analysis of instrumental data on earthquakes of 1960–2005 in the Irkutsk amphitheater shows that the majority of the earthquakes form a wide (150–300 km) band of diffuse seismicity along the marginal suture of the Siberian platform. In accordance with established regular spatiotemporal patterns of the distribution of earthquakes, this band belongs to the Sayan-Baikal seismic belt, associated with the destruction process at the boundary of large lithospheric blocks. The band is located on the northern periphery of the belt and, the deformable substrate being highly monolithic, this sharply weakens the seismicity within the band. Because of the tectonic origin of earthquakes in such a vast platform territory, undoubted evidence for induced seismicity around the Angara cascade reservoirs, and the intense economic development of the region, the problem of seismic hazard in the southern Siberian platform should be regarded as one of the most significant objects of geodynamic research. 相似文献
7.
Numerous dams have been constructed in the midstream and downstream regions of Lancang River, which form a complex cascade reservoirs system. The safety of dams is critical for water resource management of the whole system. To check the safety of dams, this study used the MIKE 11 model to simulate flood routing along the Lancang River from Xiaowan dam to Jinghong dam under extreme situations of 100-, 500-, 1000-, 5000-, and 10,000-year design floods throughout the whole cascade reservoirs system. The design flood events used as the input for the MIKE 11 model contains the design flood hydrograph of the upstream reservoirs and corresponding flood hydrographs of the intermediate areas. The design flood hydrograph of the upstream reservoirs was obtained using the Equal Frequency Factor Method, and the corresponding flood hydrograph of the intermediate areas was obtained using the Equivalent Frequency Regional Composition Method. The results show that all dams are safe for the 100-, 500-, 1000-, and 5000-year design flood situations throughout the whole cascade reservoirs system, whereas the Manwan and Jinghong dams have a risk of overtopping under a 10,000-year design flood. The curves showing the relationship between the highest water level and return period for the dams are also presented. 相似文献
8.
珠江干流梯级开发对鱼类的影响与减缓对策 总被引：1，自引：0，他引：1
2013年6—7月对珠江龙滩库尾至长洲坝下江段干支流鱼类进行了调查,共采集到鱼类6418尾,隶属于10目23科82属122种.分析了渔获物的种类组成与分布、生态类型、珍稀濒危特有鱼类采样情况、各江段群落相似度和鱼类多样性等,并与该区域鱼类历史记录进行了对比分析.总体来看,珠江干流梯级开发后,由于大坝阻隔、水文情势改变等,鱼类资源发生了较大变化,河海洄游性鱼类和河口鱼类受大坝阻隔影响分布范围变窄;珍稀濒危特有鱼类由于生境破坏,种群规模变小,濒危程度加剧;库中江段流水性鱼类种类数和资源量显著下降,静缓流鱼类成为优势种;外来鱼类种类多、分布广.对导致珠江干流鱼类资源衰退的其他原因进行了分析,主要包括过度捕捞、生境破坏、水污染和外来鱼类入侵等.针对珠江干流梯级开发及鱼类资源现状,提出了栖息地保护、河流连通性恢复、鱼类增殖放流站建设、生态调度、渔政管理和生态补偿等措施建议. 相似文献
9.
金沙江下游4个梯级水电站总装机容量相当于两座三峡水库,是“西电东送”中部地区的源头工程,工程效益发挥对经济社会发展意义重大。2012年以来,向家坝、溪洛渡、乌东德和白鹤滩电站等陆续蓄水运行,层层拦截金沙江的泥沙,2013—2020年向家坝出库年输沙量均值下降至152万t,减幅超过99%。大量泥沙淤积在梯级水库内,同时向家坝以下河道发生长距离冲刷。本文以自金沙江下游工程筹建以来的观测资料为基础,针对梯级水库的泥沙淤积和坝下游河道冲刷规律开展研究,结果表明:金沙江下游四个梯级电站自建成运行至2020年底,累计淤积泥沙约5.98亿m3,其中溪洛渡库区淤积量占比达92.5%,2013-2020年溪洛渡和向家坝水库排沙比分别为2.64%和22.2%,其水库泥沙主要淤积在常年回水区的干流河道内,以死库容内淤积为主,侵占有效库容的比例小于1.3%。金沙江下游库区干流河道的峡谷特征明显,淤积多表现为主河槽的平铺式淤高。溪洛渡和向家坝库区淤积的泥沙沿程分选特征明显,越靠近坝前,中数粒径减小、细颗粒泥沙沙量百分数增加,极细颗粒泥沙会在库区一定范围内大量沉积。向家坝下游河床普遍冲刷,但... 相似文献
10.
筑坝拦截对黑河河道沉积物粒度空间分布的影响 总被引：2，自引：1，他引：1
河流沉积物对流域环境变化具有敏感响应,其粒度参数能反映沉积环境中物质来源和水动力环境.本文以黑河流域上中游为研究区域,探究河流沉积物粒度对流域环境变化的响应.从黑河上中游干流22个主要控制断面采集河床沉积物样品,采用筛分法和吸管法对沉积物样品粒度参数进行测定,并分析其空间分布规律对筑坝拦截为主的环境改变响应.研究结果表明：受梯级水库建设影响,黑河上中游泥沙粒径大小差异显著.干流库区泥沙粒径较自然河段明显减小,分选很好,呈正偏或极正偏尖锐分布,而且在库区不同沉积高度上表现出分层沉积特征;坝下游河段因遭受强烈冲刷,较自然河段泥沙粒径粗化显著,分选变差,偏态趋向极正偏,峰态尖锐化;水库回水区受水库壅水及下泄清水的双重制约,泥沙粒度参数介于自然河段和坝下游河段之间,整体分选中等,呈极正偏尖锐分布;沉积环境分析表明,上游支流河段沉积物粒度特征受泥沙供给和物源特征的影响较水动力条件显著,干流河段沉积物粒度特征主要受水动力条件控制.研究结果既符合河流上中游沉积物粒度分布规律,也反映了河流环境变化对沉积物粒度组成的影响. 相似文献
11.
《水文科学杂志》2013,58(3):450-464
Abstract On the basis of analysing the genesis, recurrence and severity of flood hazards, a regional flood hazard analysis of the southern area of East Siberia has been carried out. The greatest flood hazard corresponds to the relatively densely populated area of southern East Siberia: the Upper Yenisei, Angara and Upper Lena river basins and the Lake Baikal watershed. Typically, the most hazardous floods include those caused by surges produced by damage to the dams of the Angara—Yenisei hydropower cascade; flash floods are also an extreme hazard. Maximum runoff factors were used to delineate regions within the study area, and the hazard severity was scored for the Irkutsk region. An inventory of the ice-dam and ice-jam areas, as well as of the streamflow sites with maximum runoff of different origins predominating in the Angara and Lena river basins, showed that the study area includes 78 and 19 ice-dam and ice-jam locations, respectively. A high recurrence of ice dams and ice jams is also observed on other rivers. 相似文献
12.
河流及水库等水生态系统中的溶解性无机碳(DIC)是全球碳循环与大气、陆地和海洋之间碳相互作用的重要组成部分.以澜沧江云南段上游天然河段及下游梯级水库群形成的连续体为研究对象,分析了河库连续体表层水体中水化学特征、溶解性无机碳浓度及其碳同位素时空分布特征.研究结果表明:河库连续体水体中溶解无机碳(DIC)及其同位素(δ13 C DIC)组成特征总体表现为:DIC浓度丰水期较低,枯水期较高,平均值分别为2.59±0.44和3.30±0.37 mmol/L;δ13 C DIC值丰水期偏负、枯水期偏正,平均值分别为-8.52‰±0.38‰和-6.95‰±0.53‰,与自然河流的季节变化特征相似.水体DIC来源主要包括土壤及水体有机质分解生成的CO 2、碳酸盐风化和水气界面CO 2的交换过程.澜沧江河库连续体中DIC浓度及δ13 C DIC组成的时空异质性特征与流域岩性、土壤生物地球化学过程以及微生物活动强度等均有较大关系.当前,澜沧江梯级水库群建库时间短,梯级联合运行下调度复杂,水文条件多变,梯级水库对河流重要生源要素——碳累积影响方面的“水库效应”还不明显. 相似文献
13.
A. V. Latyshev R. V. Veselovskiy A. V. Ivanov A. M. Fetisova V. E. Pavlov 《Izvestiya Physics of the Solid Earth》2013,49(6):823-835
Based on the paleomagnetic study of intrusive and explosive Permian-Triassic traps in the Angara River basin, Siberian Platform, it is established that the formation of the traps was marked by three short and highly intense bursts in magmatic activity, which resulted in the intrusion of three large dolerite sills (Tolstomysovsky, Padunsky and Tulunsky) and the deposition of the tuffs of the Kapaevsky Formation. These magmatic bursts occurred against the long-lived less intense background magmatism, which caused the formation of small intrusive bodies and tuff sequences. The geochronological data and correlation of the Angara traps to the effusive trap sequences in the north of the Siberian Platform (Norilsk and Maymecha-Kotuy regions) indicate that intrusion of the Tolstomysovsky sill and eruption of its comagmatic tuffs of the Kapaevsky Formation occurred in the Early Triassic. The obtained paleomagnetic data contradict the existing idea that the Padunsky and Tulunsky sills are coeval. Moreover, these data show that the magmatic bodies of different ages were mistakenly referred to the same sill. 相似文献
14.
三峡水库香溪河流域梯级水库浮游植物群落结构特征 总被引：7，自引：3，他引：4
于2005年10月、2006年1、4、7月对三峡水库香溪河流域3座水库(古洞口一级水库、古洞口二级水库和香溪河库湾)组成的梯级水库的浮游植物种类组成、优势种、群落结构、密度和生物多样性指数进行了周年调查研究.共鉴定出浮游植物7门58属121种(含变种),以绿藻和硅藻种类最多,绿藻有26属49种,占40.50%;硅藻14属41种,占33.88%;其次是甲藻,3属11种,占9.09%;蓝藻5属7种,占5.79%;隐藻3属7种,占5.79%;其它藻类仅占4.96%.浮游植物在古洞口一级水库共有25属31种,古洞口二级水库29属40种,香溪河库湾46属81种.优势度分析显示:古洞口一级水库藻类优势类群为硅藻门、绿藻门,古洞口二级水库为硅藻门、隐藻门和甲藻门,香溪河库湾为绿藻门、硅藻门、甲藻门和隐藻门.3座水库浮游植物年均密度分别为1.110×106、4.837×105和1.734×106 cells/L;其中,最高密度出现在香溪河库湾(4.87×106 cells/L),最低密度出现在古洞口二级水库(5.76×105 cells/L).运用主成分分析对梯级水库进行水质分析,表明沿着水库的梯度水质逐渐恶化.Shannon-Wiener多样性指数和Pielou均匀度指数在3座水库间无明显差异,而香溪河库湾Margalef丰富度指数显著大于古洞口一级、二级水库.前两个指数与浮游植物优势种的评价结果显示,香溪河流域梯级水库处于中污染状态. 相似文献
15.
筑坝改变河流生源要素迁移转化过程及浮游植物群落分布特征,影响河流生态系统结构与功能。为探究梯级筑坝河流浮游植物群落结构特征及其关键驱动因子,2016年丰水期、2018和2021年丰、枯水期在澜沧江开展了浮游植物群落及相关环境要素的调研。本文重点对比分析了丰水期自然河道段和水库浮游植物间的差异,基于广义相加模型(GAM)建立浮游植物与环境要素间的关系,研究发现:丰水期浮游植物生物量显著高于枯水期,丰、枯水期浮游植物群落结构均呈现上游以硅藻门为主,中下游以绿藻门、蓝藻门为主的变化特征。营养盐和水库的水力停留时间(HRT)是导致上、下游浮游植物生物量差异的关键环境要素;总磷、水温和HRT是影响浮游植物群落多样性指数的主要环境要素;总磷、氨氮是影响丰富度指数的关键环境要素。本研究结果有助于深化理解梯级筑坝河流生态环境效应。 相似文献
16.
17.
水库建设改变了河流水文情势及物质迁移转化过程,从而影响水环境质量。为探究梯级筑坝影响下河流氮、磷的空间分布特征及其形成机制,以澜沧江为研究对象,于2016年和2021年分别开展了沿程水环境监测,对比分析水体中氮、磷及其形态浓度在水库建成前后的变化及沿程分布特征,探究氮、磷变化及其沿程分布的主控因子和影响机制。结果表明：由于河流建库蓄水淹没的土地释放大量土壤有机氮,新建水库段(2021年)水体总氮(TN)浓度相比于建库前(2016年)显著上升;由于建库后水流流速减缓而促进颗粒态磷沉降,水体总磷(TP)浓度显著下降。此外,河流建库蓄水后原自然河道的水环境特征改变且利于沉积物磷的释放,筑坝后水体磷酸盐(PO43--P)占生物可利用磷(Bio-P)的比例显著上升。受沿程土地利用的影响,从上游到下游水体TN浓度总体上逐渐升高,而水体TP浓度由于水库的截留效应逐渐降低。筑坝增加的水力停留时间为水库氮、磷转化提供了有利条件,主要表现为溶解性无机氮以硝态氮为主转变为以氨氮为主;同时,Bio-P中PO43--P的占比... 相似文献
18.
Problems arising in modeling long-term variations in rivers rising from lakes are discussed in the context of the theory of correlation of non-Gaussian stochastic processes and with the use of Fokker–Plank–Kolmogorov equation. Numerically simulated runoff values of the Angara River rising from Lake Baikal are given. 相似文献
19.
Multidisciplinary studies carried out in 2007–2008 revealed the features of concentration dynamics of biogenic and organic substances, bacterio- and phytoplankton, and chlorophyll in different reaches of the Enisei River. By the development state of bacterio- and phytoplankton, saprobity index, total primary production g O2/(m2 day), and self-purification index, the water refers to the third quality class (satisfactorily clean), β-mesosaprobic. The Enisei refers to the oligotrophic type upstream of the Angara mouth and to the mesotrophic type downstream of it. 相似文献
20.
Complex geophysical investigations of the earth dam of the Irkutsk hydroelectric power plant (HEP) revealed strong negative
anomalies of the natural electric field (NEF). These anomalies are associated with focal mechanisms of earthquakes, in which
subhorizontal compressive stresses prevail. The sources of such earthquakes are located in the south of the Baikal rift zone.
Their epicentral distances are comparable with the range of the action of precursors of earthquakes with M > 5. NEF anomalies correlate with an increase in the filtration at the earth’s dam base in the Angara fault zone along the
Angara River bed. In the shape of their plots, manifestations of these NEF anomalies are similar to variations in the ratios
of velocities of longitudinal and transverse waves before earthquakes in the Garm region. 相似文献