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1.
1952-2011年鄱阳湖枯水变化分析   总被引:17,自引:11,他引:6  
闵骞  占腊生 《湖泊科学》2012,24(5):675-678
利用鄱阳湖区1952-2011年水文监测资料,分析鄱阳湖近60 a来枯水特征及其变化规律;从流域降水、五河来水、长江上中游来水、湖盆形态等方面的变化,探讨鄱阳湖枯水变化原因.结果表明,进入21世纪后的近11 a鄱阳湖枯水程度显著加剧,尤其是近5 a来最低水位不断被刷新;造成鄱阳湖枯水变化的最主要原因是流域降水和五河来水的相应变化,其次是长江上中游来水变化,湖盆形态变化对于近10 a来枯水加剧起到了推波助澜的作用;三峡大坝蓄水以后,长江上中游来水变化对鄱阳湖枯水变化的控制作用呈现逐渐加强态势.  相似文献   

2.
研究了鄱阳湖流域在1955-2002年间的径流系数的变化,重点分析了它与水循环的两个基本要素:降水量和蒸发量的关系,同时对其原因进行了初步的探讨.经分析,在鄱阳湖流域中,径流系数较大的是饶河流域和信江流域,较小的是抚河流域;在年内变化上,4-6月为五河流域径流系数比较大的月份,这与鄱阳湖流域降水集中期相对应.在空间上,4-6月仍然以饶河流域和信江流域相对较大,而抚河流域较小,特别是8月份的径流系数远小于其他四河;年代际变化上,1990s径流系数增加较为显著.尽管鄱阳湖流域的径流系数除了受气候因子的影响外,还受到水土流失和地形等因素的影响,但是降水量的增加,特别是暴雨频率的增加仍然是其主要影响因素,蒸发量的减小对径流系数的增加也有一定程度的影响.径流系数与气温并无明显的线性相关关系.  相似文献   

3.
周建银  高菲  元媛  黄仁勇  闫霞 《湖泊科学》2023,35(2):696-708
为探索三峡水库运行前后长江中下游干流及两湖径流过程的变化及其驱动因素,利用宜昌、监利、大通、七里山、湖口共5个水文站的流量资料,分析了各站径流过程的变化特征及其成因。结论:(1)各站年径流量均减少,但除七里山站之外,其它各站减少比例均小于10%且变化不显著;(2)干流各站月径流量最大减幅发生在10月,而七里山站、湖口站分别发生在7月、4月;(3)干流各站月径流量最大增幅发生在3月,而七里山站、湖口站分别发生在1月、6月;(4)宜昌站,1—4月径流量增加是三峡水库入库径流增加和水库调度的共同作用结果,6—8月径流量减少的主因是三峡水库入库径流量减少,5、9、10月径流量变化的主因是三峡水库调度;(5)监利站,径流量的变化与宜昌站表现出高度的一致性,但冬季各月径流量的增幅均大于宜昌站;(6)大通站,4—6月径流量变化方向与湖口站一致,其它月份变化方向均与宜昌站一致。(7)七里山站,7月径流量减少的主因是洞庭湖流域来水减少,9、10月径流量减少的主要原因是荆江分流减少,但洞庭湖流域来水减少也是重要原因。(8)湖口站,4、5月径流量减少的主因是流域降水减少,9、10月径流量减少的主要原因是鄱阳...  相似文献   

4.
刘慧丽  戴国飞  张伟  廖兵 《湖泊科学》2015,27(2):266-274
鄱阳湖流域内湖库资源众多,柘林湖作为鄱阳湖最大的入湖湖库,是鄱阳湖流域内最大的调节湖库,对鄱阳湖入湖径流有一定的影响,在鄱阳湖的入湖流量中占重要地位.本文以鄱阳湖流域内纳入水质良好湖泊的柘林湖为例,通过对柘林湖的形成及湖泊水系生态环境演变进行探讨,分析近30年来该湖水生生态环境的变化及其关键驱动力因子.综合研究表明:柘林湖水生生物多样性有下降趋势,水质有先变差后改善的趋势,其变化的驱动力主要是流域内人口数量增加、城镇化工业化进程加快、入湖污染负荷逐年增长、滨湖区生态安全屏障受人为破坏以及资源开发不合理等.只有处理好"人湖"和谐、"三次飞跃"和"四大转变",并采取科学合理的措施进行集成研究和综合治理,才能行之有效地改善柘林湖水生生态环境,并发挥其应有的生态效应,从而保障鄱阳湖入湖"一湖清水".  相似文献   

5.
6.
Abstract

Poyang Lake is the largest freshwater lake in China, and plays a major role in flood mitigation, restoration and conservation of the ecological environment in the middle Yangtze River basin. Sediment load and streamflow variations in Poyang Lake basin are important for the scouring and deposition changes of this lake. However, these hydrological processes are heavily influenced by human activities, such as construction of water reservoirs, and land-use/land cover changes. By thorough analysis of long series of sediment and streamflow obtained from five major hydrological stations, we systematically investigated the spatial and temporal patterns of these hydrological processes and the hydrological responses to human activities using the Mann-Kendall trend test, the double cumulative mass curve and the linear regression method. The results show: (1) no significant change in streamflow followed by an increasing tendency after the 1990s that turns to be decreasing about 2000; and (2) a sharp increase of sediment load during the late 1960s and 1970s triggered by extensive deforestation (during the “Cultural Revolution” in China) followed by a tendency to decrease after the early 1980s. Construction of water reservoirs has greatly reduced the sediment load of the Poyang Lake basin, and this is particularly the case in the Ganjiang River, where the sediment load changes may be attributed to the trapping effects of the Wan'an Reservoir, the largest water reservoir within the Poyang Lake basin. There is no evidence to corroborate the influence of water reservoirs on the streamflow variations. It seems that the streamflow variations are subject mainly to precipitation changes, but this requires further analysis. The current study may be of scientific and practical benefit in the conservation and restoration of Poyang Lake, as a kind of wetland, and also in flood mitigation in the middle Yangtze River basin that is under the influence of human activities.

Citation Zhang, Q., Sun, P., Jiang, T. & Chen, X.-H. (2011) Spatio-temporal patterns of hydrological processes and their hydrological responses to human activities in the Poyang Lake basin, China. Hydrol. Sci. J. 56(2), 305–318.  相似文献   

7.
鄱阳湖水龄季节性变化特征   总被引:3,自引:1,他引:2  
基于环境水动力学模型EFDC源程序,建立了染色剂模型和水龄模型,在将模型与航测水文数据验证吻合的基础上,分别计算了鄱阳湖自然条件下春、夏、秋、冬季的水龄和倒灌前后鄱阳湖染色剂和水龄分布的变化,以及五河水系各分支河流水龄.分季节的水龄计算表明鄱阳湖水体交换受季节性来水影响明显.夏、秋季的水龄相对较小,在多数年份又受到长江水倒灌的影响导致水龄有所增大;冬、春季水龄较大,亦无长江水倒灌现象,相较于夏、秋季,水域面积明显减少.分支流的水龄计算表明,西南湖区的水体交换主要受到赣江的影响,西北湖区水体交换主要受到修水和赣江的影响,南部湖区主要受到抚河与信江的影响,东部湖区主要受到饶河的影响,湖心区和入江水道则受到五河水系的综合影响.同时水龄的研究表明拟建的鄱阳湖水利枢纽工程"调枯不调洪"的原则是合理的,为鄱阳湖水利枢纽工程论证提供了重要的参考依据.  相似文献   

8.
The dynamic responses of wetlands to upstream water conservancy projects are becoming increasingly crucial for watershed management. Poyang Lake is a dynamic wetland system of critical ecological importance and connected with the Yangtze river. However, in the context of disturbed water regime in Poyang Lake resulting from human activities and climate change, the responses of vegetation dynamics to the Three Gorges Dam (TGD) have not been investigated. We addressed this knowledge gap by using daily water level data and Landsat images from 1987 to 2018. Landsat images were acquired between October and December to ensure similar phenological conditions. Object-oriented Artificial Neural Network Regression for wetland classification was developed based on abundant training and validation samples. Interactions between vegetation coverage and water regimes pre and post the operation of the TGD were compared using classification and regression trees and the random forest model. Since the implementation of the TGD in 2003, Poyang Lake has become drier, especially during the dry season. A more rapid plant growth rate was observed post TGD (44.74 km2 year−1) compared to that of the entire study period (12.9 km2 year−1). Average water level for the antecedent 20 days most significantly affected vegetation before 2003, whereas average water level for the antecedent 5 or 10 days was more important after 2003. The impoundment of the TGD after the flood season accelerated the drawdown processes of Poyang Lake, and the rapidly exposed wetlands accelerated vegetation expansion during the dry seasons, resulting in shrinkage and degradation of the lake area. This study deepens our knowledge of the influences of newly developed dams on lakes and rivers.  相似文献   

9.
Huai River Basin, as the sixth largest river basin in China, has a high‐regulated river system and has been facing severe water problems. In this article, the changing patterns of runoff and precipitation at 10 hydrological stations from 1956 to 2000 on the highly regulated river (Shaying River) and less‐regulated river (Huai River) in the basin are evaluated at the monthly, seasonal and annual scales using the Mann–Kendall test and simple linear regression model. The results showed that: (1) No statistically significant trends of precipitation in the upper and middle Huai River Basins were detected at the annual scale, but the trend of annual runoff at Baiguishan, Zhoukou and Fuyang stations in Shaying River decreased significantly, whereas the others were not. Moreover, the decreasing trends of runoff for most months were significant in Shaying River, although the trend of monthly precipitation decreased significantly only in April in the whole research area and the number of months in the dry season having significantly decreasing trends in runoff was more than that in the wet season. (2) The rainfall–runoff relationship was significant in both highly regulated river and less‐regulated river. In regulated river, the reservoirs have larger regulation capacity than the floodgates and thus have the smaller correlation coefficient and t‐value. In Huai River, the correlation coefficients decreased from upper stream to downstream. (3) The regulation of dams and floodgates for flood control and water supply was the principal reason for the decreasing runoff in Huai River Basin, although the decreasing precipitation in April in this basin was statistically significant. The findings are useful for recognizing hydrology variation and will provide scientific foundation to integrated water resources management in Huai River Basin. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

10.
1961-2003年间鄱阳湖流域气候变化趋势及突变分析   总被引:21,自引:2,他引:19  
本文利用1961-2003年间鄱阳湖流域14个气象站的气温、降水量、蒸发量等观测数据和8个主要水文站的流量数据,研究该时段内鄱阳湖流域的气候变化趋势、突变及其空间分布的差异.研究表明,鄱阳潮流域气温和降水均在1990年发生突变,继而呈现显著的上升趋势;在季节变化上,冬季平均气温在1986年发生突变,增温显著;夏季降水量和夏季暴雨频率均在1992年发生突变增加,暴雨频率增加是夏季降水量增加的主要原因;蒸发皿蒸发量和参照蒸散量均呈现显著下降趋势,该变化在夏季尤为明显.上述变化趋势均以1990s最为显著,这与长江流域气候变化趋势基本一致.在空间分布上,饶河水系、信江水系和赣江下游等气候变化更为显著.笔者认为,鄱阳湖流域气候变化在长江流域中比较突出.该流域1990s暖湿气候在加强;气温的升高、降水量和暴雨频率的增加以及蒸发量的下降强化了五河流量的增加趋势,由此可大致判定鄱阳湖流域气候变化与洪涝灾害之间可能存在的关系,这可为理解气候变化在该流域的响应和预测该流域未来可能的洪涝灾害提供依据.  相似文献   

11.
Most of the water from the Nile originates in Ethiopia but there is no agreement on how land degradation or climate change affects the future flow in downstream countries. The objective of this paper is to improve the understanding of future conditions by analysing historical trends. During the period 1964–2003, the average monthly basin‐wide precipitation and monthly discharge data were collected and analysed statistically for two stations in the upper 30% of the Blue Nile Basin and monthly and 10‐day discharge data of one station at the Sudan–Ethiopia border. A rainfall–runoff model examined the causes for observed trends. The results show that, while there was no significant trend in the seasonal and annual basin‐wide average rainfall, significant increases in discharge during the long rainy season (June to September) were observed at all three stations. In the upper Blue Nile, the short rainy season flow (March to May) increased, while the dry season flow (October to February) stayed the same. At the Sudan border, the dry season flow decreased significantly with no change in the short rainy season flow. The difference in response was likely due to the construction of weir in the 1990s at the Lake Tana outlet that affected the upper Blue Nile discharge significantly but affected less than 10% of the discharge at the Sudan border. The rainfall–runoff model reproduced the observed trends, assuming that an additional 10% of the hillsides were eroded in the 40‐year time span and generated overland flow instead of interflow and base flow. Models concerning future trends in the Nile cannot assume that the landscape runoff processes will remain static. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

12.
The regional terrestrial water cycle is strongly altered by human activities. Among them, reservoir regulation is a way to spatially and temporally allocate water resources in a basin for multi-purposes. However, it is still not sufficiently understood how reservoir regulation modifies the regional terrestrial- and subsequently, the atmospheric water cycle. To address this question, the representation of reservoir regulation into the terrestrial component of fully coupled regional Earth system models is required. In this study, an existing process-based reservoir network module is implemented into NOAH-HMS, that is, the terrestrial component of an atmospheric–hydrologic modelling system, namely, the WRF-HMS. It allows to quantitatively differentiate role of reservoir regulation and of groundwater feedback in a simulated ground-soil-vegetation continuum. Our study focuses on the Poyang Lake basin, where the largest freshwater lake of China and reservoirs of different sizes are located. As compared to streamflow observations, the newly extended NOAH-HMS slightly improves the streamflow and streamflow duration curves simulation for the Poyang Lake basin for the period 1979–1986. The inclusion of reservoir regulation leads to major changes in the simulated groundwater recharges and evaporation from reservoirs at local scale, but has minor effects on the simulated soil moisture and surface runoff at basin scale. The performed groundwater feedback sensitivity analysis shows that the strength of the groundwater feedback is not altered by the consideration of reservoir regulation. Furthermore, both reservoir regulation and groundwater feedback modify the partitioning of the simulated evapotranspiration, thus affecting the atmospheric water cycle in the Poyang Lake region. This finding motivates future research with our extended fully coupled atmospheric–hydrologic modelling system by the community.  相似文献   

13.
由于湖泊生态问题日益突出,湖泊生态系统安全状态已经成为人们关注的热点问题,了解湖泊水生态系统的状况并根据湖泊生态系统健康状况开展精准治理和生态修复与保护尤为重要。本文基于对鄱阳湖及其流域生态环境的长期监测数据和资料收集,采用综合指标体系法,从物理形态、水文、水环境、水域生态、湿地生态和社会服务6个方面构建了鄱阳湖生态系统健康评估的指标体系,主要涵盖了湖泊口门状况、“五河”入湖径流变异程度、入湖河流水质达标率等26个指标。依据设置的阈值等级得到鄱阳湖生态系统健康评价各层次健康状况等级,通过对各湖泊生态系统各指标得分进行加权计算,得出生态系统健康评估准则层和目标层的得分,最终对鄱阳湖生态系统健康进行了客观的评价。结果表明,构建的湖泊生态系统健康评价体系针对性强、科学全面、具有可操作性,可为鄱阳湖及类似通江湖泊的生态系统健康评价提供案例和方法借鉴。评价结果表明鄱阳湖健康体征状况目标层得分为73.45分,评价结果为亚健康,鄱阳湖水生态系统健康主要受泄流能力、水文节律变化、富营养化程度和物种多样性的影响。最后根据鄱阳湖的水生态系统健康评分等级探讨了鄱阳湖水生态系统中亟需解决的问题,针对性地提出了...  相似文献   

14.
微塑料作为新型环境污染物正日益受到人们密切关注,为探索微塑料在鄱阳湖流域的污染状况,以鄱阳湖流域"五河"入湖口的沉积物为研究对象,分别在3个水文周期(平水期、丰水期和枯水期)选择6个典型区域采集沉积物进行分析.采用浮选分离方法及金相显微鉴定技术,分析鄱阳湖"五河"入湖口沉积物中微塑料的类型、丰度和表面形貌等特征,旨在揭示鄱阳湖沉积物中微塑料的空间分布规律及不同水位期的动态变化.研究结果显示微塑料的类型有碎片类、发泡类、薄膜类和纤维类,其中主要以碎片类微塑料为主,所占百分比为51.95%;70%的微塑料粒径<1 mm,微塑料(<5 mm)的平均丰度为811.11 n/kg,6个样点的微塑料丰度值表现为朱港 > 吴城 > 渡头乡 > 龙口 > 瑞洪镇 > 南矶山.6个样点的微塑料丰度值与鄱阳湖水位动态均具一致性,在枯水期所占比例最高,达到44.41%;平水期次之,达到31.52%;丰水期所占比例最低,仅占24.07%.不同水期、不同样地存在不同程度的微塑料污染问题警示人们要重视塑料垃圾的排放及其污染问题,以减少对湖泊、河流等湿地生态环境的影响.  相似文献   

15.
The refill operation of Three Gorges Reservoir (TGR) in the end of flood season significantly alters the water level regimes in Poyang Lake by reducing Yangtze River flow discharge. This study aims to investigate the impact of TGR refill operation on water level probability distribution of the Poyang Lake. The multiple linear regression model was established to estimate the water level with catchment inflow and Yangtze River flow as explanatory variables. A probability distribution of water level was derived and the refill operation effects were quantified by comparing the water level distribution at Xingzi station in the Poyang Lake before and after TGR. It is revealed that Yangtze River flow, rather than the catchment inflow is the dominant factor affecting the water level of Poyang Lake during TGR refill operation period. Results also show that the water level distribution estimated by the derived distribution method can be accepted as a theoretical distribution and has a comparable accuracy as the directly fitted distribution method before TGR. The derived method can be adapted to the environment change, thus is well suited for estimating the water level distribution after TGR. It is observed that Xingzi water levels with different design frequencies have been reduced due to the TGR refill operation. The water level reductions induced by TGR refill operation are 1.28, 0.87, and 0.50 m corresponding with design frequencies of 50, 90 and 99 %, respectively. The results from this work would improve the understanding of the TGR effects on the downstream river–lake system and provide scientific evidences for formulating better scheme for water resources management in this region.  相似文献   

16.
The hydroclimatology of prairie‐dominated portions of the Lake Winnipeg watershed was investigated to determine the possible presence of trends and shifts in variables that may influence the streamflow regimes and water quality of Lake Winnipeg. The total annual streamflow, precipitation, runoff ratio and daily maximum streamflow in the two major tributaries of the Assiniboine River and Red River were analysed for a range of nonstationary behaviours. Each of these rivers has been gauged for more than 90 years. The methods used included a nonparametric Mann–Kendall test modified to account for diverse memory properties (i.e. short term versus long term) and a Bayesian change point detection model to identify possible segments of time series with inconsistent nonstationary behaviour. Although there is no evidence of statistically significant trends in precipitation and streamflow in the Assiniboine River watershed, a shift‐type nonstationarity in annual runoff and runoff ratio was observed in this area, which is manifested in the form of a sequence of wet and dry spells during the last century. Precipitation and runoff metrics in the American portion of the study area (i.e. Red River watershed) were characterised with both gradual and abrupt changes with an extremely increasing rate of streamflow beyond that of intensified precipitation. The nonproportional watershed runoff response is attributed to the dynamic nature of contributing areas that, together with the semiarid climate, leads to sudden changes of streamflow due to major or even some times minor changes in climate inputs. It is evident that streamflow in the depression‐dominated landscapes of the semiarid glaciated plains of North America is particularly sensitive and vulnerable to minor climate variability and change. This study provides valuable insights into the highly complex precipitation–runoff relationship in depression‐dominated landscapes and could have important implications for water management in this part of North America and comparable regions. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

17.
Lateral inflows control the spatial distribution of river discharge, and understanding their patterns is fundamental for accurately modelling instream flows and travel time distributions necessary for evaluating impacts of climate change on aquatic habitat suitability, river energy budgets, and fate of dissolved organic carbon. Yet, little is known about the spatial distribution of lateral inflows in Arctic rivers given the lack of gauging stations. With a network of stream gauging and meteorological stations within the Kuparuk River watershed in northern Alaska, we estimated precipitation and lateral inflows for nine subcatchments from 1 July to 4 August,2013, 2014, and 2015. Total precipitation, lateral inflows, runoff ratios (area-normalized lateral inflow divided by precipitation), percent contribution to total basin discharge, and lateral inflow per river kilometre were estimated for each watershed for relatively dry, moderate, or wet summers. The results show substantial variability between years and subcatchments. Total basin lateral inflow depths ranged 24-fold in response to a threefold change in rainfall between dry and wet years, whereas within-basin lateral inflows varied fivefold from the coastal plain to the foothills. General spatial trends in lateral inflows were consistent with previous studies and mean summer precipitation patterns. However, the spatially distributed nature of these estimates revealed that reaches in the vicinity of a spring-fed surficial ice feature do not follow general spatial trends and that the coastal plain, which is typically considered to produce minimal runoff, showed potential to contribute to total river discharge. These findings are used to provide a spatially distributed understanding of lateral inflows and identify watershed characteristics that influence hydrologic responses.  相似文献   

18.
The present study focusses on the analysis of water stable isotopes to contribute to understanding the hydrology of the Lake Urema wetland system in central Mozambique towards conservation management.Lake Urema Wetland is located in the Gorongosa National Park at the southernmost extent of the East African Rift System and is situated entirely within the Urema catchment. Of particular concern to the park’s management is the understanding of hydrological processes as these may trigger transformations of ecosystems, habitat losses and wildlife migrations. Concerns over the Lake Urema wetland’s drying up and the trapping of sediments in the floodplain have been raised for some time by conservationists.Water samples were collected for stable water isotope analyses during the wet and the dry seasons for the period 2006–2010 from springs, boreholes, rivers, and Lake Urema. In addition monthly composite precipitation was collected at two rain gauges.The results show that Lake Urema is maintained throughout the dry season merely from water generated during the wet season. It receives water from wet season precipitation and the runoff generated from this precipitation. The water source areas of the lake are the Gorongosa Mountain and the Barue Basement geomorphological units. Consequently, the source of the sediments which have been trapped into the lake and the floodplain has to be identified in these two catchment areas and urgent action is required to rescue the lake. This water body constitutes a groundwater buffer system which supports a unique wetland landscape. The annual inundations’ processes leading to the recharge-drainage cycle in the floodplain are most sensitive to the deposition of sediments, changing hydraulic gradients, and reducing wet season inflows and increasing drainage rates.  相似文献   

19.
The nonparametric Mann-Kendall test and the Pettitt test were employed to examine the change trends and shifts of runoff and sediment input to Poyang Lake between 1961 and 2013. Water balance and linear regression models were used to evaluate the impacts of climate variability and human activities on the runoff and sediment discharge changes. The results showed that runoff inputs to the lake had insignificant temporal trends and change points, while sediment inputs had significant decreasing trends, with an abrupt change in 1989. Quantitative assessment demonstrated that human activities led to a small decrease (5.5%) in runoff inputs to the lake, and a dramatic (121.4%) decrease in sediment inputs to the lake between the reference period (before the change point) and the human-influenced period (after the change point). This work provides a useful reference for future policy makers in water resource utilization and environmental safety of the Poyang Lake basin.  相似文献   

20.
Abstract

A snowmelt runoff model is derived for relatively small rivers. The model involves the main components of the catchment water budget, physiographical and some other factors: water equivalent of snow cover, precipitation, antecedent moisture content, daily snowmelt, non-uniformity of snow cover, retention capacity of the basin, and percentage of forest area. The model structure includes calculations of the daily values of snowmelt excess and the transformation of these values into discharges at the outlet of the basin based on meteorological observations and appropriate distribution functions. Both calculations are made separately for open and forest areas. The parameters of the model were derived by optimization methods. The linear model based on the superposition principle is used to transform the discharges of a small river into total inflow into a large reservoir. The combined model was used to forecast for five days in advance daily mean inflows into the Gorky and Kuibyshev reservoirs (on the River Volga), using the observed and forecast discharges of the small rivers as input.  相似文献   

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