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1.
Fisheries in large tropical reservoirs in South America 总被引:6,自引:0,他引:6
Miguel Petrere Jr 《Lakes & Reservoirs: Research and Management》1996,2(1-2):111-133
2.
Trends in low flows of German rivers since 1950: Comparability of different low‐flow indicators and their spatial patterns
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Climate change, land‐use shifts, reservoir storage, and water withdrawals impact low flows in rivers, creating challenges for ecological integrity and human uses. A systematic investigation of river discharges was carried out for 79 stream gauges in Germany. Available time series between 1950 and 2013 were analysed for trends in annual minimum low flows, discharge deficits, and low‐flow durations. The application of different low‐flow indicators led to similar spatial patterns, although each metric is used for different purposes in water management applications. Statistical tests identified significant discharge trends at more than half of the stations investigated. Low‐flow trends since 1950 tended to be catchment specific, suggesting that climate change has not been the dominant driver. Most of the gauges investigated showed statistically significant increases in low flows. This can be mainly attributed to reservoir management. For rivers showing snow‐ and icemelt‐dominated flow regimes, such trends are probably overlain by climate‐driven changes (increasing amounts of rainfall, earlier snowmelt in spring). In contrast, stations showing statistically significant decreases in low flows were correlated with areas of decreasing mining activity. Hydrologic impacts of climate change are widespread and significant, but the results here suggest that human river management remains the dominant hydrologic driver on many rivers. 相似文献
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Water management in the transboundary Rio Grande/Bravo (RGB) Basin, shared by the US and Mexico, is complicated by extreme hydrologic variability, overallocation, and international treaty obligations. Heavy regulation of the RGB has degraded binationally protected ecosystems along the Big Bend Reach of the RGB. This study addresses the need for integrated water management in Big Bend by developing an alternative reservoir operation policy to provide environmental flows while reducing water management trade‐offs. A reach‐scale water planning model was used to represent historical hydrology (1955–2009), water allocation, and reservoir operations, and key human water management objectives (water supply, flood control, and binational treaty obligations) were quantified. Spatially distributed environmental flow objectives and an alternative reservoir rule curve were developed. We simulated current and alternative water management policies and used an iterative simulation–evaluation process to evaluate alternative policies based on water system performance criteria with respect to specified objectives. A single optimal policy was identified that maximized environmental flows while maintaining specified human objectives. By changing the timing but not the volume of releases, the proposed reservoir re‐operation policy has the potential to sustain key ecological and geomorphic functions in Big Bend without significantly impacting current water management objectives. The proposed policy also improved water supply provisions, reduced average annual flood risk, and maintained historical treaty provisions. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
5.
A. Bronstert A. Brdossy C. Bismuth H. Buiteveld M. Disse H. Engel U. Fritsch Y. Hundecha R. Lammersen D. Niehoff N. Ritter 《河流研究与利用》2007,23(10):1102-1125
Land‐use changes effects on floods are investigated by a multi‐scale modelling study, where runoff generation in catchments of different sizes, different land uses and morphological characteristics are simulated in a nested manner. The macro‐scale covers the Rhine basin (excluding the alpine part), the upper meso‐scale covers various tributaries of the Rhine and three lower meso‐scale study areas (100–500 km2) represent different characteristic land‐use patterns. The main innovation is the combination of models at different scales and at different levels of process representation in order to account for the complexity of land‐use change impacts for a large river basin. The results showed that the influence of land‐use on storm runoff generation is stronger for convective storm events with high precipitation intensities than for long advective storms with low intensities. The simulated flood increase at the lower meso‐scale for a scenario of rather strong urbanization is in the order of 0 and 4% for advective rainfall events, and 10–30% for convective rain storms with a return period of 2–10 years. Convective storm events, however, are of hardly any relevance for the formation of floods in the large river basins of Central Europe, because the extent of convective rainstorms is restricted to local occurrence. Due to the dominance of advective precipitation for macro‐scale flooding, limited water retention capacity of antecedent wet soils and superposition of flood waves from different tributaries, the land‐use change effects at the macro‐scale are even smaller, for example at Cologne (catchment area 100 000 km2), land‐use change effects may result in not more than 1–5 cm water level of the Rhine. Water retention measures in polders along the Upper and Lower Rhine yield flood peak attenuation along the Rhine all the way down to the Dutch border between 1 and 15 cm. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
6.
Sareeha Nadarajah W. M. H. Kelum Wijenayake Upali S. Amarasinghe 《Lakes & Reservoirs: Research and Management》2019,24(3):287-298
Many reservoirs provide multiple benefits to people around the world, in addition to primary uses such as irrigation. Thus, reservoir management should address their multiple uses. The water quality of ten irrigation reservoirs in Sri Lanka was examined in the present study with the objective of better understanding the effects of hydrological regimes on reservoir water quality and trophic state. Basic limnological parameters pertinent to the nutrient loads to, and trophic state of, the reservoirs were collected from June 2013 to February 2016. The sampling period was arbitrarily divided into two periods of approximately similar duration (period 1 = June 2013–September 2014; period 2 = October 2014–February 2016) to investigate whether or not there was a seasonal variation in the water quality parameters. Although temporal and spatial variations were observed, most water quality parameters were within the levels acceptable for drinking water standards. The 10 reservoirs were also ordinated by principal component analysis (PCA) on the basis of the water quality parameters of the two sampling periods in a two‐dimensional score plot. Reservoirs in the first principal component (PC1) axis were represented by negative scores attributable to the dissolved oxygen concentration and pH and, to a lesser extent, by electrical conductivity and chlorophyll‐a concentration. Positive scores in PC1 were represented by reservoirs with a score loading attributable to alkalinity, nitrate concentration, Secchi depth, temperature and seston weight and, to a lesser extent, from the total phosphorus concentration. There was a significant negative correlation of PC1 scores with relative reservoir water‐level fluctuation (RRLF; the ratio of mean reservoir water‐level amplitude to mean reservoir depth). Furthermore, Carlson's trophic index also were influenced by RRLF, although not by hydraulic retention time (HRT), indicating allochthonous nutrient inputs into the irrigation reservoirs were mainly governed by RRLF, but not by HRT. Thus, the results of the present study provide useful insights into achieving desirable reservoir water quality through the manipulation of the hydrological regime. 相似文献
7.
Considerable attention has been paid to the downstream effects of reservoirs on the ecology of rivers, streams and wetlands. However, most reservoirs were constructed well before ecological concerns became prominent. Little attention has been given to the question of what extent existing structures and management systems can accommodate changes. The paper discusses this matter and a range of associated issues. It is concluded that many problems can be rectified by structural means but that such rectification will be very expensive. While based primarily on Australian systems, the conclusions and examination are considered to be globally applicable. 相似文献
8.
With the purpose of finding out whether seasonal water level fluctuations could affect water quality in a reservoir subjected to those changes, trends in environmental variables and in phytoplankton and zooplankton assemblages were analysed. The reservoir's hydrological cycle was characterized by three regimes. The maximum level phase lasted from January to the beginning of June, the emptying phase existed between mid‐June to the beginning of September and the minimum level phase lasted from mid‐September to the beginning of the first autumn/winter rain events. The highest values of total phosphorus, soluble reactive phosphorus, nitrate, water colour and chlorophyll a were found during the minimum level phase. The phytoplankton assemblage was dominated by taxa typical of meso‐eutrophic environments during the emptying and minimum level phases. However, during the maximum level phase, taxa generally found in more oligotrophic systems were observed here also. Similar to other disturbed systems, the zooplankton assemblage was dominated by Rotifera, except in summer and autumn when the cladoceran Ceriodaphnia quadrangula and/or the copepod Tropocyclops prasinus became dominant. Although those shifts seem to be related to water level variations, further research is needed to evaluate to what extent they might also be induced by other seasonal factors acting independently of water fluctuations. Based upon the obtained data, suggestions for reservoir management are proposed. 相似文献
9.
Thorsten D. Mosisch Angela H. Arthington 《Lakes & Reservoirs: Research and Management》1998,3(1):1-17
Over the last 30 years, the use of motorised recreational craft on inland waters has increased significantly, and it is likely that this trend will continue. This growing use of rivers, lakes and water storage reservoirs for recreational purposes has led to concerns about increasing anthropological pressures on freshwater environments. As a result, numerous studies focusing on the possible impact of power boats on inland waterbodies have been undertaken since the early 1970s, when attention started to be drawn to environmental impacts associated with this type of recreation. This paper presents an overview of identified and documented physical, chemical and biological impacts as a result of motorised recreational activities on lakes and reservoirs. Relevant literature, including research papers, government reports and bibliographies, was consulted in the preparation of this review. It has become obvious that in the past, biological impacts have been underestimated. Thus, there is a need for further, more focused, research into the impacts on not only freshwater ecosystems but on terrestrial biota surrounding recreational waters. 相似文献
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One hundred years of applied storage reservoir theory 总被引:1,自引:0,他引:1
V. Klemeš 《Water Resources Management》1987,1(3):159-175
The paper summarizes what the author considers to be the most important and most interesting aspects of the development of the applied deterministic as well as stochastic theory of reservoir storage during the past century. 相似文献
12.
采用美国陆军工程兵团的水库调度软件模型HEC-ResSim对清江梯级水库进行了模拟调度演算和效益评估.模型分别选用1955~2005年丰、平、枯典型年3小时历史实测径流资料,通过与常规调度方法的结果相比较,提出了适宜于该流域梯级特性的调度规则.模拟研究的结果表明,HEC-ResSim模型对于丰水年、平水年以及所有年份的蓄水期调度效果优于常规的方法,而在枯水年及所有年份的供水期的调度效果改进不明显. 相似文献
13.
随着矿区建设,煤矿生产与区域瓣相互影响日益突出。根据神府,东胜煤田煤矿开发方式和分布位置的不同,将矿点井田区份为井矿,缓丘高平原区露天矿和河道滩区露天矿三种类型,针对其生产布局特点和环境影响的差异,提出了相应的治理模式。 相似文献
14.
Today's water systems require integrated water resource management to improve the water supply for conflicting water uses. This research explores alternative policies to improve the water supply for two conflicting uses, hydropower and environmental, using the Leishui River basin and Dongjiang reservoir as a case study. First, the natural flow regime prior to reservoir construction (pre‐1992) was estimated by performing a statistical analysis of 41 years of daily streamflow data (March 1952–February 1993). This natural flow regime was used as a template for proposing environmental flow (e‐flow) requirements. The post‐reservoir flow regime (post‐1992) (March 1993–February 2011) was analysed to estimate the streamflow alteration. Results show that the natural flow regime has been completely transformed; post‐1992 winter normal flows are greater, and summer flows are smaller than pre‐1992 conditions. Also, the occurrence of natural floods has been prevented. Second, a planning model was built of the current operation of the Dongjiang reservoir and used for comparison of four alternative water management policies that considered e‐flow releases from the Dongjiang reservoir. The scenarios that considered combinations of the current operational policy and e‐flow releases performed better in terms of hydropower generation than the current operation. Different volumes of e‐flow requirements were tested, and an annual e‐flow volume of 75% of the pre‐1992 hydrograph was determined to generate the most hydropower while providing for environmental water needs. Trade‐offs are essential to balance these two water management objectives, and compromises have to be made for both water uses to obtain benefits. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
15.
A Modeling System for the Evaluation of Water Resources Management Strategies in Thessaly,Greece 总被引:4,自引:2,他引:4
A modeling system was developed to evaluate the sustainability of water resources management strategies in the two major basins
of Thessaly Region in Greece, namely the Pinios River and the Lake Karla basins. The intense and extensive agriculture of
water demanding crops, such as cotton, and the absence of reasonable water resources management have lead to a remarkable
water demand increase, which is usually fulfilled by the over-exploitation of groundwater resources. This unsustainable practice
has deteriorated the already disturbed water balance and accelerated water resources degradation. The modeling system consists
of a hydrological model, a reservoir operation model and methods for the estimation of water demands. The study area was sub-divided
into sub-basins and water balance analyses were performed for each sub-basin and each control node of the system for a number
of water resources management strategies. Four strategies of hydro-technical project development were coupled with two strategies
of groundwater withdrawal and three water demand strategies. In total, more than 24 water management strategies were evaluated.
The results showed that, under the existing water resources management, the water deficit of the Pinios River and Lake Karla
basins is very large. However, the development of proposed hydro-technical projects in the Pinios River basin coupled with
water demand management measures, like improvement of existing water distribution systems, change of irrigation methods, and
changes of crop cultivation could alleviate the problem and lead to sustainable and ecological use of water resources in the
study area. 相似文献
16.
长江流域上游控制性水库群联合防洪调度研究 总被引:8,自引:4,他引:4
长江流域水系复杂,防洪对象分布范围广,控制性水库的防洪调度目标具有多元化、分布多区域特征,如何科学运用水库防洪库容,有序兼顾各区域防洪是流域控制性水库群联合防洪调度的关键。选取溪洛渡、向家坝与三峡水库组成的水库群为对象,基于大系统分解协调原理,先通过逐次分解各防洪区域对溪洛渡、向家坝两库预留防洪库容的要求,在结合区域间洪水遭遇关联性分析的基础上,提出两库防洪库容在协调川江与长江中下游两区域防洪中的分配方案;同时对三峡水库的防洪调度方式深入优化,提出适当扩大对城陵矶防洪补偿库容分配方案。研究成果表明,联合调度方案可进一步减少长江中下游分洪量,对于提高整个流域防洪减灾水平,完善长江流域库群防洪调度体系具有重要意义。 相似文献
17.
深圳市小型水库在城市防洪、供水、生态体系中有着重要作用,但其功能效用没有得到很好的发挥。通过分析深圳市小型水库所面临的水库泄洪能力不足、日常管理信息化程度不高、应急应变能力差等问题,提出从法律法规建设、管理系统和自动化建设、应急体系建设、人才队伍建设等方面来加强小型水库管理的建议,以更好地发挥小型水库在现代化城市体系中功能效用。 相似文献
18.
浙江省小型水库土石坝病险分析及对策 总被引:1,自引:0,他引:1
浙江省共有小型水库3800多座,占水库总数的95.8%,其中土石坝又占小型水库总数的90%以上。通过对全省小型水库土石坝的病险分类和失事原因分析,并有针对性地为千库保安建设标准提供依据。 相似文献
19.
The Burgomillodo Dam, located in the middle Rio Duraton (north Spain, Duero Basin), has created a small eutrophic reservoir with a capacity of 15 × 106 m 3 and a maximum depth of 40m. Burgomillodo Reservoir is solely used for producing hydroelectric power. The regulated flow pattern of hypolimnial waters is characterized by higher daytime flows than those by night, with low flows at weekends all the year round. The environmental impact generated by this hydropower scheme on the river downstream was assessed by comparing physiochemical characteristics and aquatic communities of an upstream site (reference station) with those of three downstream stations, which were located 0–2, 2–5, and 7–6 km below the dam. Water temperature, pH and dissolved oxygen were significantly lower downstream from the reservoir. Hardness, alkalinity, suspended inorganic matter, and conductivity had reduced annual variability below the dam. Photosynthetic activity was directly involved in the recovery of dissolved oxygen and pH values. Species richness and abundance of macrophytes increased just below the dam. Macrobenthic and fish communities were composed of higher numbers of potamic species. Number of taxa, density, biomass, and diversity were higher at the reference site, recovering their values as the distance below the reservoir increased. Macrobenthic trophic structure was changed by an increase in predators and filter feeders and a decrease in shredders. Environmental impact values for the macrobenthic community living just below the dam were higher than those for the fish community. It is concluded that the main physiochemical factors involved in environmental impacts were dissolved oxygen deficit and short-term flow fluctuations for the macrobenthic community, and oxygen deficit for the fish fauna. Benthic macroinvertebrates appear to be the best aquatic organisms for detecting changes and for reflecting the spatial recovery of environmental conditions. 相似文献
20.
The present study focuses on the growing problem of the impacts of human displacement resulting from hydropower dam construction, within the context of the integrated lake basin management of dam reservoirs. Dam‐forced displacement and resettlement can pose severe challenges to the environmental, economic and social sustainability of a reservoir basin. A case study in Quang Nam Province, central Vietnam, suggests that many resettled communities experience impoverishment due to the lack of adequate replacement land, declines in supplemental food sources and reduced access to natural resources. In response to such situations, resettled residents may (i) destroy lake catchment forests for the purpose of converting them to farmland or engage in illegal logging; (ii) increase agrichemical inputs on reduced land, thereby polluting run‐off and groundwater; and (iii) place increased pressure on fish stocks and wildlife. Examples are provided from central Vietnam to illustrate the need for applying management approaches that allows the affected people to become beneficiaries of dam projects and for including civil society organisations in resettlement planning. The hydropower authority can fund benefit‐sharing mechanisms, including village‐level electrification and payment for environmental services schemes, in which resettled populations are paid for forest maintenance and protection to prevent erosion and deforestation, and reservoir access can be provided for fishing, aquaculture and agriculture. Civil society organizations can advocate for residents’ interests and for reallocation of protected forest land for community forestry. These approaches can be supported by an inclusive reservoir management board working to achieve environmental sustainability, economic growth and social equity. 相似文献