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1.
This paper examines ecosystem restoration practices that focus on water temperature reductions in the upper mainstem Willamette River, Oregon, for the benefit of endangered salmonids and other native cold‐water species. The analysis integrates hydrologic, natural science and economic models to determine the cost‐effectiveness of alternative water temperature reduction strategies. A temperature model is used to simulate the effects of combinations of upstream riparian shading and flow augmentations on downstream water temperatures. Costs associated with these strategies are estimated and consist of the opportunity costs of lost agricultural production and recreation opportunities due to flow releases from an up‐stream reservoir. Temperature reductions from another strategy, hyporheic flow enhancement, are also examined. Restoration strategies associated with enhanced hyporheic cooling consist of removal/reconnection of current obstacles to the creation of dynamic river channel complexity. The observed reduction of summer water temperatures associated with enhanced channel complexity indicates that restoring hyporheic flow processes is more likely to achieve cost‐effective temperature reductions and meet the total maximum daily load (TMDL) target than conventional approaches that rely on increased riparian shading or/and combinations of flow augmentation. Although the costs associated with the hyporheic flow enhancement approach are substantial, the effects of such a long‐term ecological improvement of the floodplain are expected to assist the recovery of salmonid populations and provide ancillary benefits to society. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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G. C. Poole S. J. O'Daniel K. L. Jones W. W. Woessner E. S. Bernhardt A. M. Helton J. A. Stanford B. R. Boer T. J. Beechie 《河流研究与利用》2008,24(7):1018-1031
We develop and illustrate the concept of ‘hydrologic spiralling’ using a high‐resolution (2 × 2 m grid cell) simulation of hyporheic hydrology across a 1.7 km2 section of the sand, gravel and cobble floodplain aquifer of the upper Umatilla River of northeastern Oregon, USA. We parameterized the model using a continuous map of surface water stage derived from LIDAR remote sensing data. Model results reveal the presence of complex spatial patterns of hyporheic exchange across spatial scales. We use simulation results to describe streams as a collection of hierarchically organized, individual flow paths that spiral across ecotones within streams and knit together stream ecosystems. Such a view underscores the importance of: (1) gross hyporheic exchange rates in rivers, (2) the differing ecological roles of short and long hyporheic flow paths, and (3) the downstream movement of water and solutes outside of the stream channel (e.g. in the alluvial aquifer). Hydrologic spirals underscore important limitations of empirical measures of biotic solute uptake from streams and provide a needed hydrologic framework for emerging research foci in stream ecology such as hydrologic connectivity, spatial and temporal variation in biogeochemical cycling rates and the role of stream geomorphology as a dominant control on stream ecosystem dynamics. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Nitrogen dynamics were studied in the interstitial environment (i.e. hyporheic zone) of a sandy‐bottom stream in a rural landscape. A third‐order stream in Brittany (France) was studied at 11 stations (riffles) to evaluate spatial patterns of water exchange between surface and interstitial habitats. More intensive sampling was conducted in three riffles selected according to their hydrological characteristics. Chemical characteristics (especially nitrogen) and microbial denitrification were studied at 12.5 and 25 cm depth upstream, and 25 cm depth downstream of each riffle. This study confirms that the interstitial habitat of a N‐rich stream acts as a sink for the nitrate‐nitrogen. Experimental manipulation of sediment cores indicates that denitrification is limited by carbon in surface (i.e. benthic) and by nitrate in hyporheic sediments. River regulation increases inputs of fine sediments, modifies river channel location, and generates changes in the spatial patterns of biogeochemical processes, water origins, and hydrologic exchanges. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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Water regulation may alter hydraulic head gradients with consequences for the exchange of water between the river and the hyporheic zone. The objective of this study was to investigate the effect of discharge on hyporheic water quality in a regulated Swedish boreal river during a 10‐day experimental period with a sequence of alternating high‐ and low‐flow episodes. A 250 m reach was instrumented with 28 piezometers placed at 150 and 300 mm below the river bed or below the mean groundwater level in the floodplain, and these piezometers were used to measure temperature, oxygen, electric conductivity and pH. High daily variation in air temperature during the first 3 days was transmitted vertically through the stream water into the hyporheic zone within hours. An oxygen saturation of 100% in the river water corresponded to 60–70% saturation at 150 mm depth and 30% at 300 mm depth. The hyporheic oxygen concentration at 150 mm depth decreased during the experimental period, falling into a range that is potentially harmful to incubating salmonid eggs. This was interpreted as a long‐term response to the overall regulation regime, rather than a response to short‐term water regulation during the experiment. Even though the effect of short‐term regulation on the quality of hyporheic water in the river bed was limited, there was a more pronounced effect on the quality of floodplain hyporheic water. Most of the driving forces for temporal variation of water quality in the river bed came vertically from the river water, rather than from the lateral exchange. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Low streamflows and warm stream temperatures currently limit habitat and productivity of trout, including native Lahontan cutthroat trout in Nevada's Walker Basin. Environmental water transfers, which market water from willing sellers to instream uses, are evaluated to improve instream habitat. We use River Modelling System, an hourly, one‐dimensional hydrodynamic and water quality model, to estimate current and potential environmental water transfer effects on stream temperatures. Model runs simulate a range of environmental water transfers, from 0.14 to 1.41 cms, at diversions and reservoirs for wet year 2011 and dry year 2012. Results indicate that critically warm stream temperatures generally coincide with low flows, and thermal refugia exist in East Walker River, a tributary of the Walker River. Environmental water transfers reduce maximum stream temperatures by up to 3 °C in dry years and are more effective in dry years than wet years. This research suggests that environmental water transfers can enhance instream habitat by improving water quality as well as increasing instream flow. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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河道内砂砾滩形态发挥着重要的河流生态作用,水库下游河道沉积物相对有限,砂砾积累构建砂砾滩可作为恢复河道下游生态系统的重要手段。作者进行现场生态水文数据及地貌形态分析,提出河道水生物栖息地生态恢复方法,在北方水库夏季洪峰冲击作用下,顺水流沉积,形成砂砾浅滩。通过测定水温、悬浮颗粒有机质浓度、水力梯度及基流条件下砂砾滩周边浅水宽度等特征值,分析动态构建的砂砾滩及物理塑造沙岛的生态功能属性。结果显示,该水生物栖息地修复方法通过增加夏季基流中水力梯度、潜流交换率和悬浮颗粒有机质的保留率,修复河床基质渗透性,同时延长河道浅水层湿度边界范围,结合粗沙积累效果,增加河道形态复杂性,改善潜流交换效率和悬浮颗粒有机质浓度,最终加强流域内温度的异质性,修复河流水生物栖息地的生态功能。 相似文献
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水库运行对下游河岸潜流带水位-温度影响研究 总被引：1，自引：0，他引：1
选取浙江省新安江大坝下游尾水至富春江水库某一河段作为试验场地,实时监测同一河流剖面的河道水位、温度以及河岸水位与温度分布。通过分析侧向潜流交换流量,定量描述侧向潜流交换的空间非均质性和动态特征,刻画河岸潜流带与河道水体水位、温度之间的响应关系。结果表明:本次试验剖面上的侧向潜流交换流量变化范围为-8.36~3.87 m2/s,监测时间段内单位长度上的潜流交换量可达2.49 m2;河岸带侧向潜流区同一剖面不同观测井处的潜流流量呈线性相关,且离河道越远,潜流区水位波动振幅消减越多,响应越滞后,潜流交换流量越小;受水库下泄水流影响,河道水温日波幅很小,河岸含水层具有显著的垂向温度分层。在垂直方向上,冬季浅层河岸温度较低,深层河岸温度较高,夏季则相反,同时浅层温度梯度较大,尤以地面以下0.8~1.7 m范围内温度梯度最大,深层温度梯度小;在水平方向上,离河道越远,受河道入渗水影响越小,温度越高。揭示了水库运行对下游河岸潜流带的影响规律,为河流潜流带生态影响评估提供参考。 相似文献
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A collaborative study among three nations (France, Belgium, Netherlands) along the Meuse River developed a consistent approach for collecting and interpreting macroinvertebrate data. Specific mesohabitats were sampled in 16 locations along an 800‐km stretch of this lowland regulated river. The objective was to assess the ‘river health’ using macroinvertebrate communities as indicators of biological and ecological variation in space. The main changes in assemblages were investigated using multimetric and multivariate approaches. The authors examined relationships between faunal variations and both physico‐chemical gradients and man‐made disturbances. We related species traits to faunal changes and habitat characteristics. Both a gradual shift from a macroinvertebrate assemblage dominated by insects to a community dominated by crustaceans and molluscs and a drastic decrease in biotic index values were observed along the longitudinal gradient. Taxa were distributed according to oxygen, nitrate and ammonium concentrations, pH, conductivity and summer hydraulic conditions. But major faunal differences among sites could not be explained simply by physico‐chemical variables. The trait analysis underlined the role of temporary habitats in structuring the summer macroinvertebrate community of sites of the uppermost French sector, which supported the most diverse community in terms of trait combination. Downstream the macroinvertebrate community exhibited a more simple and less stable functional organization. We concluded that the Meuse River exhibited both a high biodiversity and a ‘reasonably good’ water quality in the upper reaches. Two transition zones highlighted the influence of a high degree of human impact on stream integrity. Regulation for navigation, ship traffic and heavily polluted effluent discharges influenced instream conditions via multiple processes determining a decline of both habitat stability and diversity. However, the rare occurrence of habitat‐sensitive species in the lower reaches indicated that a partial recovery of communities may be predicted if restoration and protection of disturbed (especially riparian) habitats are fulfilled. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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根据松辽流域省界河流水质监测断面的资料 ,依照《地面水环境质量标准》(GB 3838- 88)和《地表水资源质量标准》(SL 6 3- 94)对省界河段进行水质评价 ,结果表明 ,全流域多数界河水体受到不同程度的污染 ,达 类以上水质的河段占 77.8% ,并有加重污染的趋势。因此 ,必须采取有效措施保护界河水环境质量 相似文献
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采用综合评价与分类评价相结合的方法,分析乌鲁木齐河水质特征,旨在发现影响河流水质的主要污染物和污染源,为乌鲁木齐河水污染防治和水资源利用提供科学依据。结果表明:乌鲁木齐河各断面水质符合划定水域功能要求。上游和中游断面均属清洁水质,下游断面属轻污染水质。河流综合污染指数、有机类污染指数、营养盐类污染指数均沿流程顺序增高,主要污染物为化学需氧量、石油类等有机类污染物。上游断面部分工业活动、中下游生活源、农业源污水排放是影响乌鲁木齐河水质的主要污染源。 相似文献
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基于对浊漳河水系三典型支流2008年逐月进行水质监测分析,通过时空变异两个角度对这3条支流的水质进行了对比研究.结果表明:①以农业非点源污染为主的河谷平川河流水质最好;以农业非点源污染为主的高山峡谷河流,由于受到农业活动的影响,水质相对较差;受工业废水和城市生活污水污染的支流河流水质最差,有机物和氮磷指标严重超标.②3条支流中4个化学指标(NH4+-N、TN、TP、CODMn)在不同水域、不同季节具有明显差异.以农业非点源污染为主的河流氮营养盐浓度在丰水期较高,在枯水期较低,TP浓度和CODMn浓度在各个雨期之间变化不大,且相对稳定;以点源污染严重的河流氮营养盐浓度在枯水期最高,在丰水期最低,个别断面TP和CODMn污染表现突出. 相似文献
12.
River water temperature is known to be important for water quality and ecosystem processes. We quantified the degree to which lower river flows are associated with warmer river water, after accounting for seasonality and meteorological variability. We applied a systematic methodology to analyse observed mean daily river water temperature and mean daily river flow from 47 sites draining mountain, hill, and lowland catchments across the Canterbury region of Aotearoa New Zealand. We fitted regression models to remove seasonal patterns from all variables, then removed correlations between water temperature and each of three meteorological variables (solar radiation, air temperature, and earth temperature) before quantifying water temperature-river flow relationships. Strong seasonal patterns were present in water temperature and each meteorological variable across all sites. Many sites also showed strong seasonal patterns in river flows. We demonstrated that seasonal patterns must be accounted for before day-to-day associations between water temperature and meteorological variables or river flow can be characterised. Higher water temperatures were associated with lower flows for 46 of 47 sites, even after having accounted for seasonality and associations with each meteorological variable. Increases in water temperature associated with a hypothetical reduction in river flow from the median to the fifth percentile varied with the site but were 0.5°C on average. This finding has important implications for river flow management because it indicates that increased river water temperatures would accompany reduced river flows regardless of site or catchment characteristics. 相似文献
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依据连续性方程、动量方程、自由表面方程、状态方程和水质输运方程,采用有限差分法,建立河道垂向二维水动力水质模型。根据2000-2001年第6次引黄数据资料对水质模型进行调试,建立引黄济津调水工程水质模型。利用已建立的模型,对2002-2003年第7次引黄河道水质进行了预测,并将预测结果与实测数据进行比较,预测结果与实测结果基本一致,表明该模型能较好地预测引黄济津河道水质状况。同时,根据污染物浓度峰值的变化情况,分析了污染物的输移扩散及降解转化规律。 相似文献
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天津海河磷的分布特征 总被引：3，自引：0，他引：3
采集海河干流重要断面、相应排污渠以及部分支流(北运河、子牙河、南运河)共29个监测断面的水样,对样品中的溶解性活性磷(SRP)、总溶解态磷(TDP)与总磷(TP)进行测定,并分析其分布特征。结果显示:海河干流各断面的TP质量浓度为0.4~3.5mg/L,已超出GB3838—2002《地表水环境质量标准》Ⅴ类水质标准,SRP质量浓度0.09~0.75 mg/L,TDP质量浓度0.24~1.42 mg/L;各排污渠(支流)TP质量浓度0.2~5.0 mg/L,SRP质量浓度0.01~3.63 mg/L,TDP质量浓度0.12~4.16 mg/L。排污渠(支流)多数断面的含磷量比相应干流的高。天津海河总磷以总溶解态磷为主要形态,这和海河悬浮颗粒物浓度较低有关。 相似文献
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Eliza Khwairakpam Bhawna Dhawan Kuppusamy Sivakumar Jeyaraj Antony Johnson 《河流研究与利用》2023,39(2):189-199
Water quality plays a vital role in the sustenance of aquatic life, including fish. Therefore, an inclusive understanding of water quality parameters can be considered an essential step in framing the conservation and management strategy of an aquatic ecosystem. This study examines the habitat suitability of a conservation-significant fish, the Tor putitora, and two associated fishes, the Labeo dyocheilus and the Garra gotyla, in relation to the water quality parameters of the Kosi River. Four crucial water quality parameters, water temperature, dissolved oxygen, electrical conductivity, and pH, were included in the QUAL2K modeling. Furthermore, hydrological processes were modeled using the soil and water assessment tool, and flow was used as an input in the QUAL2K model. The simulated water quality was correlated with fish habitat and analyzed through the analytical hierarchical process (AHP). Results suggested that the habitats of the Kosi were more suitable in the post-monsoon rather than pre-monsoon. Tor putitora, the flagship species of the Kosi, preferred the river habitats with a lower water temperature and higher dissolved oxygen for spawning. Thus, we recommend securing such habitats and managing them in collaboration with local communities for the long-term conservation of this endangered Himalayan species. 相似文献
16.
构建黄河健康生命的指标体系 总被引：4，自引：0，他引：4
从河流生命和河流健康的本质出发,通过分析黄河自身、人类和河流生态系统的生存需求,认为连续的河川径流、通畅安全的水沙通道、良好的水质、良性运行的河流生态和一定的供水能力是现阶段黄河健康生命的标志,提出用低限流量、平滩流量、湿地面积等9个指示性因子具体表达健康黄河的标志,并给出了这些因子在未来不同阶段的量化指标. 相似文献
17.
Small‐bodied, riverine minnows that historically characterized fish assemblages of Great Plains rivers in North America have declined because of river fragmentation, dewatering, river channel degradation, river salinization and nonnative species introductions. The Pecos bluntnose shiner Notropis simus pecosensis, a member of this guild, persists in one segment of the Pecos River, New Mexico, USA. We characterized habitat associations for the species at two spatial scales. In general, N. s. pecosensis associated with fluvial habitats, but velocity association depended on body size, with larger individuals using swifter habitats. All N. s. pecosensis associated with relatively low depths (3–51 cm), which were most abundant in sites with relatively wide river channels (>25 m), especially when discharge was between 0.5 and 4.0 m3 s?1. The Pecos River sub‐segment that is occupied by the core population of N. s. pecosensis (V‐ii) had a unique combination of being buffered from direct dam effects by intervening segments and sub‐segments, high sub‐segment length, substantial sediment inputs from numerous uncontrolled tributaries, substantial base flow provided by irrigation return flows and groundwater inflows, high channel width in relation to discharge and low salinity. Although no unoccupied Pecos River segment appears to be suitable for N. s. pecosensis, habitat restoration opportunities exist within all occupied sub‐segments (V‐i, V‐ii and V‐iii) via base flow enhancement and river channel restoration. Restoration that offsets chronic effects of dams may be necessary to conserve the species. Restoration would also benefit other rare riverine minnows that coexist with N. s. pecosensis. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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辽河流域健康评价指标体系初探 总被引：4，自引：0，他引：4
辽河流域生态脆弱,河流污染严重.本文基于辽河现状,从辽河流域、河流廊道、栖息地3个尺度,确定评价指标体系,采用熵权法和集对分析不确定性理论,对辽河流域健康指标进行评价分析确定,为辽河水生态保护和修复提供决策依据. 相似文献