共查询到16条相似文献，搜索用时 250 毫秒
1.
复杂环境下华南东江中上游流域筑坝导致的水文变异 总被引：5，自引：2，他引：3
采用可视化分析软件包XmdvTool来评价复杂环境下东江中上游流域(1952-2002)水文变异以克服常规RVA方法的限制,在分离了气候变化对水文变异影响后,结合RVA方法系统地研究了华南东江中上游流域由于筑坝等人类活动引起的河流水文变异时空演化规律.结果表明:(1)1952-2002间由筑坝导致的最显著的东江中上游流域水文变异是最小3d流量,低流量持续时间、1月平均流量和7月平均流量等3个IHA因子;(2)在河源和岭下两站水文变异9个IHA因子相关图中,1月和2月平均流量,1月平均流量和最小90d流量相关图中各存在一个较为明显的线性回归趋势,表明上述因子存在较明显的相关关系;(3)东江中上游综合水文变异强度由大至小分别为:河源、龙川和岭下.运用高维水文数据可视化分析技术结合RVA方法可有效用于天然河流水文变异时空变化研究,研究结果对于东江河流生态环境管理、生态恢复和水资源一体化管理具有重要意义,可为流域水文变异的理论与方法研究提供借鉴. 相似文献
2.
从1950s开始, 云南地区部分湖泊受到了水文调控(如筑坝)和鱼类引入等流域开发活动的直接影响, 湖泊水环境与生态系统结构已出现明显改变. 开展浮游动物群落的长期生态响应评价有助于认识气候波动和人为胁迫的影响模式. 本文选取云龙天池进行了沉积物记录分析, 在重建过去100年环境变化历史的基础上开展了枝角类群落的多指标分析(物种组成、个体大小、生物量等), 进一步结合多变量分析识别了枝角类群落构建的关键驱动因子. 结果显示, 云龙天池在过去100年间经历了明显的水位波动, 约1962年以前水位较低, 1950s起的水文调控(筑坝)导致湖泊水位波动上升, 2006年以来略有下降. 枝角类群落随水位波动呈现由底栖种向浮游种占优转变的模式, 并在2006年以来底栖种略有增加. 总体上, 低水位时期底栖枝角类占优, 高水位时期浮游枝角类占优. 水体营养水平也对枝角类群落产生了较为显著的影响. 在沉积物总氮和有机质通量上升时, 长额象鼻溞(Bosmina longirostris)相对丰度和枝角类浓度都明显上升. 枝角类象鼻溞个体大小表明, 1969年鱼类引入后象鼻溞的壳长、壳刺长度、触角长度显著减小, 反映了鱼类捕食压力上升的影响. 本研究进一步揭示了水文调控和鱼类引入对湖泊环境和生物群落结构的驱动影响. 其中, 1960s以前云龙天池处于自然波动的状态, 湖泊环境和枝角类群落变化主要受气候(如降水、气温)的影响; 1960s以来人类活动的影响强度已经掩盖了气候变化的信号, 成为影响湖泊生态演化轨迹的主要因素. 为了开展有效的湖泊保护与生态治理, 有必要综合评估水文调控、鱼类引入等人类活动对湖泊生态健康的长期影响. 相似文献
3.
鄱阳湖碟形湖生物群落分布特征很大程度上受区域与主湖区水文连通性影响。由于水位波动，东部湖湾水文连通性受鄱阳湖主湖体水位影响较为敏感。本文以东部湖湾为例，分析主湖区水位变异程度及其影响，并从连通天数和发生时间等方面定量表征东部湖湾与主湖区的水文连通性，进而讨论水文连通性变化及其对湿地植物生境和候鸟栖息地的潜在影响。结果表明，当水位在13～16 m时，东部湖湾与主湖区存在着良好的水文连通关系，湿地植物适宜生境面积最大。2003年以后，鄱阳湖主湖区水位普遍降低，低枯水位持续时间延长，IHA/RVA法分析表明主湖区水位发生了中等程度改变，整体改变度为40.2%，东部湖湾与主湖区的连通关系发生明显改变，年连通天数减少了46.2 d，变化幅度为15.9%，而非连通期发生时间提前约1个月且年内时间跨度更长。水文连通性减弱造成3 10月东部湖湾平均水位下降了0.6 m，其中9 10月减少了约1 m，使薹草（Carexsp．）和苦草（Vallisneria natans）适宜水深对应的水面面积在多数月份呈增加趋势，特别是9 10月（幅度超过40%），但枯水提前导致沉水植物面积减少，湿生植物生物量增加。水... 相似文献
4.
水文干旱多变量联合设计及水库影响评估 总被引：2，自引：1，他引：1
基于东江流域博罗站月径流数据,采用游程理论提取水文干旱事件.选用Meta-Gaussian Copula函数,统计模拟水文干旱指标的多变量联合分布.采用Kendall联合重现期和最大可能权函数,设计给定联合超越重现期的水文干旱指标组合值,并定量评估水库径流调节作用对水文干旱多变量联合特征的影响.结果表明:东江流域水文干旱历时、强度和峰值的统计优选分布均为韦布尔分布.干旱指标之间具有较高的正相关性,Meta-Gaussian Copula能够很好地模拟水文干旱指标两变量和三变量联合分布.基于任意两个变量联合设计和三变量联合设计,干旱指标设计组合值位于同频位置附近,且同一个干旱指标设计值在不同变量组合之间差别较小.水库径流调节作用对于缓解东江流域水文干旱效果明显,同一组干旱指标的多变量联合超越重现期在水库影响下明显变大.联合超越重现期越小,水库对联合设计值的影响程度越大.根据目前水库运行模式,若要满足河道内最小管理流量目标,联合超越重现期10 a一遇的干旱历时、强度和峰值依然达到了约3.89~4.04月、7.20~7.97亿m3和2.99~3.12亿m3. 相似文献
5.
基于水文变异的东洞庭湖湿地生态水位研究 总被引：3，自引：2，他引：1
东洞庭湖湿地具有重要生态意义.基于东洞庭湖湿地退化的现实,认为气候变化、人类活动等因素造成水文序列发生突变,湿地生态系统适应突变前的水文环境.以城陵矶水文站1952-2006年月平均水位序列为分析对象,通过滑动T检验法找到序列的最可能突变点,以该点对序列进行分割,以变异前的月平均水位序列为对象,拟合月平均水位的最适合概率分布函数,认为概率最高处的月平均水位是区域生态水位.研究结果表明,城陵矶水文站的水位时间序列发生显著变化;与其他方法相比,本文确定的东洞庭湖湿地生态水位具有一定的合理性,对东洞庭湖湿地生态系统修复具有一定的指导意义. 相似文献
6.
洞庭湖是长江中游重要的通江湖泊,水系格局复杂.近年来在气候变化和人类活动的双重影响下,江湖关系发生变化,湖泊水文干旱事件频发.基于洞庭湖、流域和长江干流水文站点的实测数据,通过标准化水位指数和标准化径流指数识别了水文干旱事件,并运用Copula函数分析了洞庭湖-流域-长江系统水文干旱的联合概率分布特征.结果表明:在年尺度上,1964—2016年间洞庭湖共发生了9次水文干旱事件,水文干旱的发生概率为14.01%,洞庭湖-流域系统、洞庭湖-长江系统的水文干旱联合概率分别为9.65%和8.58%,表明年尺度上流域来水对洞庭湖水文干旱的影响更大.在季节尺度上,洞庭湖-流域系统春季水文干旱联合概率最高,且两者同时发生水文干旱事件的次数最多,表明洞庭湖春季水文干旱与流域入湖补给减少有密切关系;而洞庭湖-长江系统,其秋季水文干旱联合概率最大,尤其自2003年以后更加极端和频发,这一方面受秋季降水减少和流域内人类活动的影响,另一方面三峡水库秋季蓄水使长江中下游干流水位降低,长江对湖泊顶托作用减弱也是重要原因之一. 相似文献
7.
洞庭湖地处北亚热带季风湿润气候区,水情时空变化尤为明显.为了探明洞庭湖水位时空演变特征,以洞庭湖6个水位站(城陵矶、鹿角、营田、杨柳潭、南咀、小河咀)、出入湖流量("三口"总入湖流量、"四水"总入湖流量、城陵矶出湖流量)和长江干流流量(宜昌、螺山)等1985-2014年逐日数据为基础,通过构建泰森多边形计算湖泊水位,运用Morlet小波分析、层次聚类分析和地统计理论研究湖泊水位的周期性变化规律及空间分布格局和自相关性.研究结果表明:洞庭湖水位变化具有典型的季节性,且年际变化具有28和22 a的多时间尺度特征;水位空间分布格局呈现出小河咀、南咀、杨柳潭(Group 1)以及城陵矶、鹿角、营田(Group 2)两种聚类,且在不同水文季节的空间自相关性依次表现为丰水期退水期涨水期枯水期.通过建立两类水位在不同水文季节与径流量的多元逐步回归模型揭示了洞庭湖水位时空演变的驱动因素,其中Group 1水位演变主要受长江干流水文情势的影响,Group 2水位演变由出入湖径流量和长江干流径流量共同作用,并随着不同水文季节江湖关系的改变以及湖泊自身水力联系的变化而变化.研究结果对于科学认识洞庭湖水位的时空演变规律以及湖泊生态系统保护和水资源的规划、管理与调控具有重要意义. 相似文献
8.
湖泊生态水位是维持湖泊生态系统健康的重要因素.基于洞庭湖城陵矶、杨柳潭、南咀3个水文站1959-2016年日平均水位序列进行分析,采用Mann-Kendall法、累积距平法和滑动T检验法综合确定洞庭湖水位变异时间节点,结合生态水位年内展布法以及IHA-RVA法,计算分析湖泊最小和适宜生态水位,并且采用Tennant法进行合理验证,在此基础上对水文变异前、后湖泊生态水位保障度进行研究.研究结果表明:(1)洞庭湖城陵矶和杨柳潭水文站年均水位呈上升趋势,而且城陵矶站水位上升趋势显著,南咀站年均水位呈显著下降趋势.(2)洞庭湖3个典型水文站水位年际变化突变年份为2003年,突变年份基本上与三峡工程蓄水时间相符.(3)城陵矶、南咀和杨柳潭年均最小生态水位分别为21.41、28.95和27.84 m,分别占多年平均水位的86.3%、95.9%和95.7%,城陵矶、南咀和杨柳潭年均适宜生态水位分别为23.29、29.51和28.36 m,分别占多年平均水位的93.9%、97.8%和97.5%,生态水位计算结果考虑了天然湖泊水位年内丰枯变化,满足了湖泊生态目标需求.(4)洞庭湖最低生态水位保障程度较高,基本能达到80%以上,但适宜生态水位保障程度相对较低,其中2003年以后洞庭湖10月和11月生态水位保障程度显著下降,与上游水利工程蓄水有关,建议在此期间采取调度措施适当增加洞庭湖水量,以保障湖泊生态系统的健康与生物多样性. 相似文献
9.
洞庭湖是我国第二大淡水湖,与长江连通,在防洪抗旱和湿地生态保护等方面具有重要的现实意义.采用Terra/MODIS L1B遥感数据,提取了2000-2012年洞庭湖水面面积,结合同期城陵矶水位观测数据,建立了城陵矶水位与洞庭湖水面面积的绳套关系曲线.分析结果表明:2000-2012年间,洞庭湖水面面积呈现总体减少的趋势;在季节上表现为规律性的涨落,具有明显的涨(4-6月)-丰(7-9月)-退(10-12月)-枯(1-3月)的水文特征;在空间格局上表现为由湖体中心向外扩张,随后由外向湖体中心逐渐收缩的变化过程;洞庭湖水面面积与城陵矶水位之间具有较高的相关性,但不同时期的相关系数存在一定的差异:枯水期二者相关性较低,丰水期相关性最高,涨水期和退水期相关性较高;这种差异与各个时期的主导因素不同有关,长江来水对枯水期、丰水期的绳套关系影响较大,其中东洞庭湖最为明显;不论丰水年(2002年)或干旱年(2011年),洞庭湖水面面积变化与城陵矶水位之间的相关性均较高.研究结果对于深入认识江湖关系的宏观复杂性、长江中下游地区以及洞庭湖水域洪涝灾害的预防和治理都具有积极的意义. 相似文献
10.
基于长序列遥感影像数据、水位日观测数据以及高精度湖盆地形数据，通过提取洞庭湖1987—2016年湿地植被信息，并构建表征水位波动的多周期水情变量，采用逐步回归分析法识别影响洞庭湖湿地植被分布格局的关键水情变量并建立其与植被面积的响应关系.结果表明：1）1987—2016年，洞庭湖湿地典型植被面积在全湖尺度上呈增加趋势，尤其是林地面积，占比由1.77%上升为7.24%.湿地植被格局演变上，东洞庭湖呈现芦苇群落挤占苔草群落空间，并推动湿地植被整体向湖心扩张的趋势.2）影响东洞庭湖苔草和芦苇分布最关键的水情变量是丰水期水位.苔草对丰水期水情存在非线性阈值响应，丰水期平均水位维持在29 m左右，最适宜苔草生长；对于芦苇，丰水期偏枯的水情条件对其生长发育起到促进作用.涨水期和退水期水文过程是影响东洞庭湖湿地植被分布的次为重要的水情因子.涨水期、退水期水位偏低的水情条件对芦苇分布面积的扩张起促进作用. 相似文献
11.
A revised range of variability approach considering the periodicity of hydrological indicators 
下载免费PDF全文
下载免费PDF全文 Comprehensively assessing the hydrological alteration of river flows is a prerequisite for the scientific management, protection, and restoration of rivers. The range of variability approach (RVA), which is based on indicators of hydrological alteration (IHAs), is a widely used method to evaluate hydrological alteration. However, the RVA only considers the frequency of each IHA, neglecting the equally important temporal order of these IHAs. The order of IHA event can be reflected by its periodicity. On the basis of the RVA, in this study, we propose a revised RVA that considers both the frequency and periodicity of IHAs. In the revised RVA, first, the periodic time of each IHA is identified; next, the periodicity alteration (P) of river flow is calculated by comparing the periodic times of the pre‐impact‐period and post‐impact‐period IHAs; finally, P and the frequency alteration(D) in traditional RVA are incorporated into a single index (H) to reflect the overall hydrological alteration. A case study of the Xi Dayang (XDY) Reservoir and rearranged flow suggests that the traditional RVA underestimates hydrological alterations because it neglects the alteration of periodicity. Compared with the traditional RVA and its alternatives, the revised RVA could give a more comprehensive representation of hydrological alteration caused by human and nature impacts. Thus, better protection of an ecosystem could be obtained by applying this method in the evaluation and management of water resources. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
12.
Yongqin David Chen Tao Yang Chong-Yu Xu Qiang Zhang Xi Chen Zhen-Chun Hao 《Stochastic Environmental Research and Risk Assessment (SERRA)》2010,24(1):9-18
This paper presents a visually enhanced evaluation of the spatio-temporal patterns of the dam-induced hydrologic alteration
in the middle and upper East River, south China over 1952–2002, using the range of variability approach (RVA) and visualization
package XmdvTool. The impacts of climate variability on hydrological processes have been removed for wet and dry periods,
respectively, so that we focus on the impacts of human activities (i.e., dam construction). The results indicate that: (1)
along the East River, dams have greatly altered the natural flow regime, range condition and spatial variability; (2) six
most remarkable indicators of hydrologic alteration induced by dam-construction are rise rate (1.16), 3-day maximum (0.91),
low pulse duration (0.88), January (0.80), July (0.80) and February (0.79) mean flow of the East River during 1952–2002; and
(3) spatiotemporal hydrologic alterations are different among three stations along Easter River. Under the influence of dam
construction in the upstream, the degree of hydrologic changes from Lingxia, Heyuan to Longchuan station increases. This study
reveals that visualization techniques for high-dimensional hydrological datasets together with RVA are beneficial for detecting
spatio-temporal hydrologic changes. 相似文献
13.
沉水植物是湖泊生态系统的重要组成部分，其生产力和分布格局受环境因子特别是水文情势决定.洞庭湖是长江流域重要的大型通江湖泊，近年来受人为干扰和气候变化影响，水文节律与水质等环境因子发生改变，导致沉水植物出现衰退现象，急需开展科学恢复，因此有必要对洞庭湖沉水植物深入研究.本研究选取西洞庭湖为研究区域，于2018年和2019年夏季调查了12处典型生境、98个样点的沉水植物与水深、透明度等11个环境因子，采用独立样本T检验和冗余分析方法对沉水植物与环境因子的关系进行分析，对比年际水文情势变化的影响.结果表明：1）西洞庭湖沉水植物主要在水深较浅、水质更优、水体更为稳定的半阻隔子湖和自由连通的湖湾区分布，在河道及水位波动较大的区域分布较少，有、无沉水植物分布样点间存在显著差异的环境因子为水深、透明度、底泥总磷和pH；2）在有沉水植物分布的样点，沉水植物生物量与pH、水深和水体总磷呈显著相关关系；3）自然连通的季节性淹没湖泊沉水植物生物量在2018年高于2019年，可能与2019年5—8月沉水植物关键生长期出现的涨水过程有关，持续的高水位对沉水植物的生长产生了不利影响.维持自然水文节律、湖泊生境异质性与自由连通性、健康的水质等是恢复西洞庭沉水植物的关键，建议在水深低于3 m、营养盐浓度适中、流速及风浪较小的湖湾区或半阻隔湖泊开展沉水植物恢复. 相似文献
14.
Investigating the changes in streamflow regimes in response to various influencing factors contributes to our understanding of the mechanisms of hydrological processes in different watersheds and to water resource management strategies. This study examined streamflow regime changes by applying the indicators of hydrologic alteration method and eco-flow metrics to daily runoff data (1965–2016) from the Sandu, Hulu and Dali Rivers on the Chinese Loess Plateau, and then determined their responses to terracing, afforestation and damming. The Budyko water balance equation and the double mass curve method were used to separate the impacts of climate change and human activities on the mean discharge changes. The results showed that the terraced and dammed watersheds exhibited significant decreases in annual runoff. All hydrologic metrics indicated that the highest degree of hydrologic alteration was in the Sandu River watershed (terraced), where the monthly and extreme flows reduced significantly. In contrast, the annual eco-deficit increased significantly, indicating the highest reduction in streamflow among the three watersheds. The regulation of dams and reservoirs in the Dali River watershed has altered the flow regime, and obvious decreases in the maximum flow and slight increases in the minimum flow and baseflow indices were observed. In the Hulu River watershed (afforested), the monthly flow and extreme flows decreased slightly and were categorized as low-degree alteration, indicating that the long-term delayed effects of afforestation on hydrological processes. The magnitude of the eco-flow metrics varied with the alteration of annual precipitation. Climate change contributed 67.47% to the runoff reduction in the Hulu River watershed, while human activities played predominant roles in reducing runoff in the Sandu and Dali River watersheds. The findings revealed distinct patterns and causes of streamflow regime alteration due to different conservation measures, emphasizing the need to optimize the spatial allocation of measures to control soil erosion and utilize water resources on the Loess Plateau. 相似文献
15.
《国际泥沙研究》2015,(3)
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.
A spatial assessment of hydrologic alteration caused by dam construction in the middle and lower Yellow River,China 总被引：5，自引：0，他引：5
The ‘range of variability approach’ (RVA) and mapping technique are used to investigate the spatial variability of hydrologic alterations (HA) due to dam construction along the middle and lower Yellow River, China, over the past five decades. The impacts of climate variability on hydrological process have been removed during wet and dry periods and the focus is on the impacts of human activities, such as dam construction, on hydrological processes. Results indicate the following: (1) The impacts of the Sanmenxia reservoir on the hydrologic alteration are relatively slight with a mean HA value of 0·48, ranking in the last place among the four large reservoirs. (2) Xiaolangdi reservoir has significantly changed the natural flow regime downstream with mean HA value of 0·56, ranking it in first place among the large reservoirs. (3) The results of ranked median degrees of 33 hydrologic alteration indicators for 10 stations in the Yellow River show that the hydrologic alteration of Huayuankou ranks the highest among 10 stream gauges. (4) Impacts of reservoirs on hydrological processes downstream of the dams are closely associated with the regulating activities of the reservoirs. At the same time, alterations of streamflow regimes resulting from climatic changes (e.g. precipitation variability) make the situation more complicated and more hydrological observations will be necessary for further analysis. The results of the current study will be greatly beneficial to the regional water resources management and restoration of eco‐environmental systems in the middle and lower Yellow River characterized by intensified dam construction under a changing environment. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献