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1.
G. R. Kattel 《河流研究与利用》2012,28(8):1113-1120
Natural resource managers across Australia intend to promote healthy floodplain lake ecosystems with rich diversity and composition of biota because such ecosystems provide economically valuable services to society. However, management practice of these floodplain lake ecosystems is impeded by confounding effects of anthropogenic impacts and natural climate variability in recent decades. Yet, there are a few potential biological markers available that profoundly respond to ecological effects of climate change and human disturbances. Cladoceran zooplankton plays an intermediary role in food web dynamics. They show distinct responses to changes in temperature and environmental perturbations, such as acidification, nutrient loading and salinization. The effects of temperature and land‐use changes on food web dynamics and water quality, in particular, are major concerns for shallow lowland large river floodplain lakes management in Australia. Information on zooplankton assemblages and diversity can help increase our understanding of ecological processes in a wide range of environmental exposures. The study of cladoceran fossils and their ephippia preserved in floodplain lake sediment has substantially furthered our understanding of species–environment relationships at different temporal and spatial scales and allowed us to develop powerful inference models for degraded floodplain lake ecosystems. This consequently defines a benchmark of a shift from a naturally intact ecosystem to an ecologically poor regime. In this paper, I have made an attempt to persuade wetland managers through application of contemporary and palaeocladoceran communities to improve management practice of floodplain lake ecosystems in Australia by providing a range of examples. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
2.
An original modeling framework for assessment of climate variation and change impacts on the performance of complex flood protection system has been implemented in the evaluation of the impact of climate variability and change on the reliability, vulnerability and resiliency of the Red River Basin flood protection system (Manitoba, Canada). The modeling framework allows for an evaluation of different climate change scenarios generated by the global climate models. Temperature and precipitation are used as the main factors affecting flood flow generation. System dynamics modeling approach proved to be of great value in the development of system performance assessment model. The most important impact of climate variability and change on hydrologic processes is reflected in the change of flood patterns: flood starting time, peak value and timing. The results show increase in the annual precipitation and the annual streamflow volume in the Red River basin under the future climate change scenarios. Most of the floods generated using three different climate models had an earlier starting time and peak time. The assessment of the performance of Red River flood protection system is based on the flood flows, the capacity of flood control structures and failure flow levels at different locations in the basin. In the Assiniboine River Basin, higher reliabilities at downstream locations are obtained indicating that Shellmouth reservoir plays an important role in reducing downstream flooding. However, a different trend was identified in the Red River Basin. The study results show that flood protection capacity of the Red River infrastructure is sufficient under low reliability criteria but may not be sufficient under high reliability criteria. 相似文献
3.
Trends in low flows of German rivers since 1950: Comparability of different low‐flow indicators and their spatial patterns 
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下载免费PDF全文 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
4.
C. H. D. Magadza 《Lakes & Reservoirs: Research and Management》2011,16(1):15-22
The pelagic fishery of Lake Kariba comprises the introduced clupeid, Limnothrissa miodon, from Lake Tanganyika. The annual fishery catches grew logistically from 1974, when commercial fishing began. It peaked at 37 000 tonnes (estimated mean sustainable yield = 40 000 tonnes) around 1990 and declined steadily thereafter. A piecewise regression of Limnothrissa catches against time gives a breakpoint around 1987–1988. Regressions of Limnothrissa against air temperature and lake temperature gave breakpoints of 34.8 and 28.7 °C, respectively. Other studies indicate that Lake Kariba has warmed by close to 2 °C, with accompanying changes in thermal stratification. The lake phytoplankton is now dominated by Cyanophyceae, particularly Cylindrospermum raciborskii. The lake zooplankton population has greatly diminished. These data are similar to the results obtained for Lake Tanganyika (Nature 2003; 424 , 766–8). In the Lake Tanganyika study, the declining pelagic fishery has been attributed to reduced food availability resulting from a reduced phototrophic zone depth, as well as epilimnion nutrient recharge from reduced mixing. The warming observed in Lake Kariba and its environs is consistent with the IPCC Fourth Assessment Report (AR4). While the effects of global warming have been observed in large natural lakes, this is the first study in which global warming has affected the ecosystem of a large impoundment. 相似文献
5.
《Journal of Contemporary Water Research & Education》2017,160(1):100-118
Anthropogenic inputs of nutrients threaten water quality around the world, causing eutrophication and altering phytoplankton communities. In freshwater systems, certain physiochemical conditions, including high TP, low TN:TP, and warm temperatures, can lead to problematic cyanobacteria blooms. Cyanobacteria can decrease phytoplankton diversity and phytoplankton diversity has been positively linked to zooplankton diversity, suggesting that cyanobacteria may have indirect negative effects on zooplankton diversity. Using monitoring data from Lake Champlain, we tested three hypotheses: (1) cyanobacteria density and phytoplankton diversity are inversely related; (2) phytoplankton diversity and zooplankton diversity are positively related; and by extension (3) cyanobacteria density and zooplankton diversity are inversely related. Relationships were investigated separately at shallow (4–15 m) and deep (25–100 m) sites using several diversity metrics. At deep sites, cyanobacteria density was only related (positively) to zooplankton Shannon diversity. At shallow sites, all three hypotheses were supported by three of four diversity metrics; low phytoplankton richness appears to be the link between high cyanobacteria density and low zooplankton diversity. Our results suggest that cyanobacteria may indirectly reduce zooplankton diversity by decreasing resource heterogeneity, although our results based on observational data were also consistent with well‐known direct pathways. Because low biodiversity can alter ecosystem processes and impair functioning, our results suggest that shallow systems may be more responsive to global change than deeper systems. 相似文献
6.
Water is one of the most important ecosystem services because it is essential for food and energy production. The Tungabhadra basin, located in peninsular India, has a variety of challenges, including inter-basin water-sharing issues, low agricultural productivity and value, and rising need for renewable energy production. The Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) water yield model is used to analyze the consequences of climate change on water related services such as water yield and hydropower generation in the densely populated Tungabhadra basin. The impact of climate change on water supply services is studied for the period 1971–2000 as well as the future period 2021–2040. The model is calibrated using streamflow data collected at the Bawapuram gauge station in Telangana and there is a strong correlation between observed and simulated flow. The water yield for the entire basin declined by 33 and 50% under the Representative Concentration Pathways (RCP) 4.5 and 8.5 scenarios, respectively. The RCP 4.5 scenario reduces hydropower production and its Net Present Value (NPV) by 41 to 59%, whereas the RCP 8.5 scenario reduces production and NPV by 56 to 67%. The assessment of ecosystem services at the catchment scale revealed that the basin could be vulnerable to climate change due to a dramatic drop in ecosystem services. The methodology developed in this study can be applied to other river basins where quantifying ecosystem services is critical. 相似文献
7.
A crop growth simulation model was used to study the impact of climate change for the period 2010–2050 on water productivity of rainfed rice. In general, the results suggest that water productivity of rainfed rice may increase significantly in the upper basin in Laos and Thailand and may decrease in the lower basin in Cambodia and Vietnam. Significant net increases in water productivity can be achieved by applying simple adaptation options such as shifting the planting dates, applying supplementary irrigation, and increasing fertilizer inputs. 相似文献
8.
应用SWAT模型,以黄河流域伊洛河为研究对象,通过设置6种 HRUs(Hydrological Response Units)划分方案,分析了HRUs数量对SWAT模型参数和模拟性能的影响,并进一步用于伊洛河年径流变化的归因分析。结果表明:SCS径流曲线值(CN2)、土壤有效含水率(SOL_AWC)、深层土壤水渗透系数(RCHRG_DP)和河岸基流α因子(ALPHA_BNK)是伊洛河SWAT径流模拟敏感性高的几个参数。HRUs数量对SWAT模型参数和径流模拟精度影响较小。相对1971—1985年,1986—2015年气候变化和人类活动共同导致了伊洛河流域径流的减少。其中,1986—1995年、1996—2005年、2006—2015年3个时期气候变化对径流变化相对贡献率分别为68.7%、22.5%、83.1%,LUCC外的其他形式的人类活动对径流变化相对贡献率分别为30.9%、76.7%和16.9%,而LUCC的相对贡献不足1%。人类活动能够有效地缓解气候变化对径流的影响,使河道观测径流保持在相对稳定的变化范围。 相似文献
9.
The Weihe River has experienced a significant runoff decline in the past few decades, but the detailed and systematic analysis of different sub-regions of the Weihe River basin (WRB) for a long time is insufficient. Based on the data of five hydrological stations from 1957 to 2018, this study investigated the variation of annual runoff both in the whole Weihe River basin (WWRB) and its sub-regions: the upper, middle, and lower reaches of the Weihe River (URWR, MRWR, LRWR, respectively), the Jing River basin (JRB), and the Beiluo River basin (BLRB). Moreover, the contribution of climate change and anthropogenic activities on runoff change was quantified by double mass curve (DMC) and hydrological sensitivity analysis (HSA) methods. The results showed that runoff of the URWR, MRWR, JRB, BLRB, and WWRB showed significant downward trends, and with the change-point years of 1993, 1990, 1996, 1994, and 1993, respectively. Both results of DMC and HSA showed that anthropogenic activities were the main factors for runoff reduction. The contribution of human activities was largest in the JRB and BLRB, whereas lowest in the MRWR. Over the study period, land use has changed significantly in the basin, mainly manifested in the reduction of farmland, and the increase of construction land and grassland, indicating that intense anthropogenic activities have taken place. Moreover, the total water consumption of the WWRB increased evidently, which exacerbated the contradiction between supply and demand of water resources. The results of HSA showed that runoff was more sensitive to precipitation than to Ep. Precipitation reduced the runoff, while Ep increased runoff in the basin. The results of this study are helpful for understanding the regional hydrological situation in more detail, and can act as a reference for formulating reasonable water resources allocation schemes. 相似文献
10.
Rivers and streams, when fully connected to their floodplains, are naturally resilient systems that are increasingly part of the conversation on nature-based climate solutions. Reconnecting waterways to their floodplains improves water quality and quantity, supports biodiversity and sensitive species conservation, increases flood, drought and fire resiliency, and bolsters carbon sequestration. But, while the importance of river restoration is clear, beaver-based restoration—for example, strategic coexistence, relocation, and mimicry—remains an underutilized strategy despite ample data demonstrating its efficacy. Climate-driven disturbances are actively pushing streams into increasingly degraded states, and the window of opportunity for restoration will not stay open forever. Therefore, now is the perfect time to apply the science of beaver-based low-tech process-based stream restoration to support building climate resilience across the landscape. Not every stream will be a good candidate for beaver-based restoration, but we have the tools to know which ones are. Let us use them. This article is categorized under:
- Science of Water > Hydrological Processes
- Water and Life > Nature of Freshwater Ecosystems
- Water and Life > Conservation, Management, and Awareness
11.
Abstract Scenarios of global climate change were examined to see what impacts they might have on transboundary water management in the Columbia River basin. Scenario changes in natural streamflow were estimated using a basin hydrology model. These scenarios tended to show earlier seasonal peaks, with possible reductions in total annual flow and lower minimum flows. Impacts and adaptation responses to the natural streamflow scenarios were determined through two exercises: (a) estimations of system reliability using a reservoir model with performance measures and (b) interviews with water managers and other stakeholders in the Canadian portion of the basin. Results from the two exercises were similar, suggesting a tendency towards reduced reliability to meet objectives for power production, fisheries, and agriculture. Reliability to meet flood control objectives would be relatively unchanged in some scenarios but reduced in others. This exercise suggests that despite the high level of development and management in the Columbia, vulnerabilities would still exist, and impacts could still occur in scenarios of natural streamflow changes caused by global climate change. Many of these would be indirect, reflecting the complex relationship between the region and its climate. 相似文献
12.
Lee J. Baumgartner Peter Gell Jason D. Thiem Colin Finlayson Nathan Ning 《河流研究与利用》2020,36(4):645-655
Restoration programmes for degraded aquatic ecosystems frequently focus on flow restoration or reinstatement, including recovery targets for volumes of water to be used for environmental benefit. Australia's Murray–Darling Basin is an example of a major system undergoing substantial water reform to balance the needs of competing users, including the environment, within the constraints of an arid climate. This reform revolves around accounting for finite volumes of water that have been shared amongst water users. We argue that while recovering water will provide good outcomes, as a sole intervention, it is not enough to deliver the desired environmental benefits of the reform given the significantly altered state of the catchment. Here, we present 10 measures that could be used to complement planned water recovery actions. These “complementary measures” integrate recovery actions, which when strategically combined with water delivery would significantly enhance water reform efforts to generate environmental outcomes in a highly modified system. 相似文献
13.
This commentary examines the riparianization process underway in the Mekong River Commission and highlights the need to correct flawed governance processes. It offers important insights into how river basin organizations evolve and change over time. 相似文献
14.
Dramatic swings in the North Atlantic oscillation (NAO) during the 1990s motivated the authors to build a statistical model
of NAO impacts on hydropower production and energy markets in Scandinavia. Variation in the NAO index is shown to explain
55% of the variance of streamflow in Norway and up to 30% of the variance in Norway's hydropower output. It is also possible
to identify the influence of NAO anomalies on electricity consumption and prices. Government liberalization allowed a financial
market to grow around the international trading of electricity, which in Norway is produced almost entirely from hydropower.
The model offers a possible tool for predicting the effects of future NAO movements on hydropower production and energy prices
in Scandinavia. The potential influence of skillful climate prediction is discussed. 相似文献
15.
Levee‐protected floodplains along the 125‐km LaGrange Segment (LGS) of the Illinois River were screened for their abiotic suitability for alternative ecosystem services (ESs), including wetland creation, habitat, floodwater denitrification and flood‐tolerant agriculture. The suitability framework developed for this study builds upon the Land Capability Potential Index and is informed by the current understanding of the linkages between river hydrology, hydraulics, floodplain soils, floodplain vegetation and floodplain nutrient cycling. In addition to screening these floodplain areas for alternative ESs, we demonstrate how this framework can be combined with economic assessments of current floodplain services to inform how strategic floodplain reconnection (i.e. restoration of hydrologic linkages between river and floodplain for the purpose of flood mitigation and provisioning of alternative ESs) could be used to work towards sustainable floodplain management. Results show that ESs increase with upstream distance from the LaGrange Lock and Dam. This is attributed to the operation of the lock and dam generating a water level that would result in the inundation of a substantial portion of floodplain (>70 km2) up to ?60 km upstream if the levees were to be removed or set back. Comparison of the profits from current floodplain agriculture with the potential profits of flood‐tolerant agriculture suggests that overcoming the economic costs of floodplain reconnection within the LGS will likely require both conversion of reconnected floodplain lands to flood‐tolerant agriculture and payments for ESs. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
16.
Matteo Roncoroni Jade Brandani Tom I. Battin Stuart N. Lane 《Wiley Interdisciplinary Reviews: Water》2019,6(6)
The term “ecosystem engineering” emerged in the 1990s and is commonly used to refer to the activities of larger organisms like beavers and trees in rivers and streams. The focus on larger organisms may be motivated by their more visible effects on the environment. However, while it may be intuitive to suggest that the bigger the organism the bigger its potential engineering effects, there may be microscale organisms who through their number rather than their size can act simultaneously to result in significant impacts. This paper considers biofilms as a candidate ecosystem engineer. It is well known that biofilms play an important role in enriching the sediment matrix of nutrients and in stabilizing sediments. Biofilms may be critical in increasing the habitability of the benthic substratum. In this paper, we consider their potential role in the ontogeny of ecosystems in recently deglaciated terrain. We show how by changing sediment stoichiometry, decreasing sediment erodibility, and reducing surface sediment permeability they may promote primary succession on lateral, incised terraces, which are less perturbed compared with the main active floodplain. This article is categorized under:
- Water and Life > Nature of Freshwater Ecosystems
- Science of Water > Water and Environmental Change
17.
以柬埔寨境内3S河流域(3个子流域分区)和湄公河流域上段为研究区域,探讨了Topmodel在缺资料、少资料地区的应用。采用水文学方法、天气发生器以及再分析数据获取研究区域1980~2015年的气象水文长系列资料,将其作为Topmodel模型的输入,对径流过程进行了模拟。研究表明月序列确定系数高于日序列确定性系数,且都达到乙级标准。再利用该模型对研究区域的9个子流域的水资源量进行了模拟分析,结果表明Topmodel模型具有较好的适用性和良好的模拟效果,模拟结果能够反映流域水资源特性。 相似文献
18.
黄河下游河道湿地浅析 总被引：7，自引：3，他引：7
黄河属于高含沙河流,自小浪底以下河道大部分为宽浅游荡型河道,形成了特有的黄河河道湿地。研究认为:黄河下游河道湿地是黄河小浪底以下河道行洪的重要组成部分;湿地保护应考虑下游滩区的现状,并应与下游综合治理相结合;黄河下游频繁断流对湿地的破坏较大;黄河下游滩区生产堤的修建既影响防洪又不利于河道湿地发育;黄河下游河道湿地的存在有利于沿黄两岸生态环境的改善。提出黄河下游河道湿地的研究方向为:①河道典型湿地价值评估研究;②黄河下游河道湿地规模与黄河径流补给的响应关系研究;③黄河自然洪水对下游河道湿地的影响效应研究;④黄河调水调沙对河道湿地的影响效应研究等。 相似文献
19.
Apisom Intralawan Alex Smajgl William McConnell Daniel B. Ahlquist John Ward Daniel B. Kramer 《Wiley Interdisciplinary Reviews: Water》2019,6(4)
In this paper, we examine the benefits and costs of hydropower development in the Mekong River Basin. We compare four major reports—the Mekong River Commission's (MRC's) Basin Development Plan Programme, Phase 2 (BDP2), the Strategic Environmental Assessment of Hydropower on the Mekong Mainstream (SEA), the Study on the Impacts of Mainstream Hydropower on the Mekong River (MDS), and the MRC's recent council study (CS)—in order to provide the basis for a comparative analysis of the major impact evaluation literature on mainstream dam construction in the Mekong River Basin for the period of 2010–2018. The primary objective of the review is to identify points of agreement, disagreement, inconsistency, and knowledge gaps. Both Mekong River Commission reports (BDP2 and CS) suggest extensive economic benefits for proposed hydropower development, whereas the SEA and MDS indicate that the net impact would be negative. The projected impacts of hydropower development on fisheries, sediment flows, and ecosystems vary widely both in economic and biophysical terms. However, all four reports point to decreased food security and loss of local livelihoods for millions of people as major concerns related to dam development. While considerable resources have been devoted to producing these important studies, the lack of standardization across reports, especially assumptions and methodologies for economic impacts, frustrates efforts at meaningful comparison of their findings and precludes the prospect of clear analytical outcomes or policy impacts. This article is categorized under:
- Engineering Water > Planning Water
- Human Water > Value of Water
- Engineering Water > Methods