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1.
Data collected from 172 sites in 20 major river basins between 1993 and 1995 as part of the US Geological Survey's National
Water-Quality Assessment Program were analyzed to assess relations among basinwide land use (agriculture, forest, urban, range),
water physicochemistry, riparian condition, and fish community structure. A multimetric approach was used to develop regionally
referenced indices of fish community and riparian condition. Across large geographic areas, decreased riparian condition was
associated with water-quality constituents indicative of nonpoint source inputs—total nitrogen and suspended sediment and
basinwide urban land use. Decreased fish community condition was associated with increases in total dissolved solids and rangeland
use and decreases in riparian condition and agricultural land use. Fish community condition was relatively high even in areas
where agricultural land use was relatively high (>50% of the basin). Although agricultural land use can have deleterious effects
on fish communities, the results of this study suggest that other factors also may be important, including practices that
regulate the delivery of nutrients, suspended sediments, and total dissolved solids into streams. Across large geographic
scales, measures of water physicochemistry may be better indicators of fish community condition than basinwide land use. Whereas
numerous studies have indicated that riparian restorations are successful in specific cases, this analysis suggests the universal
importance of riparian zones to the maintenance and restoration of diverse fish communities in streams. 相似文献
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3.
Understanding effects of flow alteration on stream biota is essential to developing ecologically sustainable water supply
strategies. We evaluated effects of altering flows via surface water withdrawals and instream reservoirs on stream fish assemblages,
and compared effects with other hypothesized drivers of species richness and assemblage composition. We sampled fishes during
three years in 28 streams used for municipal water supply in the Piedmont region of Georgia, U.S.A. Study sites had permitted
average withdrawal rates that ranged from < 0.05 to > 13 times the stream’s seven-day, ten-year recurrence low flow (7Q10),
and were located directly downstream either from a water supply reservoir or from a withdrawal taken from an unimpounded stream.
Ordination analysis of catch data showed a shift in assemblage composition at reservoir sites corresponding to dominance by
habitat generalist species. Richness of fluvial specialists averaged about 3 fewer species downstream from reservoirs, and
also declined as permitted withdrawal rate increased above about 0.5 to one 7Q10-equivalent of water. Reservoir presence and
withdrawal rate, along with drainage area, accounted for 70% of the among-site variance in fluvial specialist richness and
were better predictor variables than percent of the catchment in urban land use or average streambed sediment size. Increasing
withdrawal rate also increased the odds that a site’s Index of Biotic Integrity score fell below a regulatory threshold indicating
biological impairment. Estimates of reservoir and withdrawal effects on stream biota could be used in predictive landscape
models to support adaptive water supply planning intended to meet societal needs while conserving biological resources. 相似文献
4.
Effects of Local Land Use on Physical Habitat, Benthic Macroinvertebrates, and Fish in the Whitewater River, Minnesota, USA 总被引:7,自引:0,他引:7
Best management practices (BMPs) have been developed to address soil loss and the resulting sedimentation of streams, but information is lacking regarding their benefits to stream biota. We compared instream physical habitat and invertebrate and fish assemblages from farms with BMP to those from farms with conventional agricultural practices within the Whitewater River watershed of southeastern Minnesota, USA, in 1996 and 1997. Invertebrate assemblages were assessed using the US EPA's rapid bioassessment protocol (RBP), and fish assemblages were assessed with two indices of biotic integrity (IBIs). Sites were classified by upland land use (BMP or conventional practices) and riparian management (grass, grazed, or wooded buffer). Physical habitat characteristics differed across buffer types, but not upland land use, using an analysis of covariance, with buffer width and stream as covariates. Percent fines and embeddedness were negatively correlated with buffer width. Stream sites along grass buffers generally had significantly lower percent fines, embeddedness, and exposed streambank soil, but higher percent cover and overhanging vegetation when compared with sites that had grazed or wooded buffers. RBP and IBI scores were not significantly different across upland land use or riparian buffer type but did show several correlations with instream physical habitat variables. RBP and IBI scores were both negatively correlated with percent fines and embeddedness and positively correlated with width-to-depth ratio. The lack of difference in RBP or IBI scores across buffer types suggests that biotic indicators may not respond to local changes, that other factors not measured may be important, or that greater improvements in watershed condition are necessary for changes in biota to be apparent. Grass buffers may be a viable alternative for riparian management, especially if sedimentation and streambank stability are primary concerns. 相似文献
5.
Chantal Gascuel-Odoux Florence Massa Patrick Durand Philippe Merot Olivier Troccaz Jacques Baudry Claudine Thenail 《Environmental management》2009,43(5):921-935
While many scientific studies show the influence of agricultural landscape patterns on water cycle and water quality, only
a few of these have proposed scientifically based and operational methods to improve water management. Territ’eau is a framework
developed to adapt agricultural landscapes to water quality protection, using components such as farmers’ fields, seminatural
areas, and human infrastructures, which can act as sources, sinks, or buffers on water quality. This framework allows us to
delimit active areas contributing to water quality, defined by the following three characteristics: (i) the dominant hydrological
processes and their flow pathways, (ii) the characteristics of each considered pollutant, and (iii) the main landscape features.
These areas are delineated by analyzing the flow connectivity from the stream to the croplands, by assessing the buffer functions
of seminatural areas according to their flow pathways. Hence, this framework allows us to identify functional seminatural
areas in terms of water quality and assess their limits and functions; it helps in proposing different approaches for changing
agricultural landscape, acting on agricultural practices or systems, and/or conserving or rebuilding seminatural areas in
controversial landscapes. Finally, it allows us to objectivize the functions of the landscape components, for adapting these
components to new environmental constraints. 相似文献
6.
Assessment of Economic and Water Quality Impacts of Land Use Change Using a Simple Bioeconomic Model
The objective of this study is to assess the economic and water quality impact of land use change in a small watershed in the Wiregrass region of Alabama. The study compares changes in water quality and revenue from agricultural and timber production due to changes in land use between years 1992 and 2001. The study was completed in two stages. In the first stage, a biophysical model was used to estimate the effect of land use change on nitrogen and phosphorus runoff and sediment deposition in the main channel; in the second stage, farm enterprise budgeting tools were used to estimate the economic returns for the changes in land use condition. Both biophysical and economic results are discussed, and a case for complex optimization to develop a decision support system is presented. 相似文献
7.
Since intensive farming practices are essential to produce enough food for the increasing population, farmers have been using
more inorganic fertilizers, pesticides, and herbicides. Agricultural lands are currently one of the major sources of non-point
source pollution. However, by changing farming practices in terms of tillage and crop rotation, the levels of contamination
can be reduced and the quality of soil and water resources can be improved. Thus, there is a need to investigate the amalgamated
hydrologic effects when various tillage and crop rotation practices are operated in tandem. In this study, the Soil Water
Assessment Tool (SWAT) was utilized to evaluate the individual and combined impacts of various farming practices on flow,
sediment, ammonia, and total phosphorus loads in the Little Miami River basin. The model was calibrated and validated using
the 1990–1994 and 1980–1984 data sets, respectively. The simulated results revealed that the SWAT model provided a good simulation
performance. For those tested farming scenarios, no-tillage (NT) offered more environmental benefits than moldboard plowing
(MP). Flow, sediment, ammonia, and total phosphorus under NT were lower than those under MP. In terms of crop rotation, continuous
soybean and corn–soybean rotation were able to reduce sediment, ammonia, and total phosphorus loads. When the combined effects
of tillage and crop rotation were examined, it was found that NT with continuous soybean or corn–soybean rotation could greatly
restrain the loss of sediments and nutrients to receiving waters. Since corn–soybean rotation provides higher economic revenue,
a combination of NT and corn–soybean rotation can be a viable system for successful farming. 相似文献
8.
We assessed the relationship between riparian management and stream quality along five southeastern Minnesota streams in 1995
and 1996. Specifically, we examined the effect of rotationally and continuously grazed pastures and different types of riparian
buffer strips on water chemistry, physical habitat, benthic macroinvertebrates, and fish as indicators of stream quality.
We collected data at 17 sites under different combinations of grazing and riparian management, using a longitudinal design
on three streams and a paired watershed design on two others. Continuous and rotational grazing were compared along one longitudinal
study stream and at the paired watershed. Riparian buffer management, fenced trees (wood buffer), fenced grass, and unfenced
rotationally grazed areas were the focus along the two remaining longitudinal streams. Principal components analysis (PCA)
of water chemistry, physical habitat, and biotic data indicated a local management effect. The ordinations separated continuous
grazing from sites with rotational grazing and sites with wood buffers from those with grass buffers or rotationally grazed
areas. Fecal coliform and turbidity were consistently higher at continuously grazed than rotationally grazed sites. Percent
fines in the streambed were significantly higher at sites with wood buffers than grass and rotationally grazed areas, and
canopy cover was similar at sites with wood and grass buffers. Benthic macroinvertebrate metrics were significant but were
not consistent across grazing and riparian buffer management types. Fish density and abundance were related to riparian buffer
type, rather than grazing practices. Our study has potentially important implications for stream restoration programs in the
midwestern United States. Our comparisons suggest further consideration and study of a combination of grass and wood riparian
buffer strips as midwestern stream management options, rather than universally installing wood buffers in every instance.
RID=" ID=" The Unit is jointly sponsored by the US Geological Survey, Biological Resources Division; the Minnesota Department
of Natural Resources; the University of Minnesota; and the Wildlife Management Institute. 相似文献
9.
The European Water framework directive (WFD) is probably the most important environmental management directive that has been enacted over the last decade in the European Union. The directive aims at achieving an overall good ecological status in all European water bodies. In this article, we discuss the implementation steps of the WFD and their implications for environmental engineering practice while focusing on rivers as the main receiving waters. Arising challenges for engineers and scientists are seen in the quantitative assessment of water quality, where standardized systems are needed to estimate the biological status. This is equally of concern in engineering planning, where the prediction of ecological impacts is required. Studies dealing with both classification and prediction of the ecological water quality are reviewed. Further, the combined emission–water quality approach is discussed. Common understanding of this combined approach is to apply the most stringent of either water quality or emission standard to a certain case. In contrast, for example, the Austrian water act enables the application of only the water quality based approach - at least on a temporary basis. 相似文献
10.
报道了盐碱地池塘、水库、湖泊养鱼中的水质改良技术。池塘水质改良措施主要为加注淡水、施用有机肥、注水与施肥相结合、改造盐碱土质、控制生石灰用量及合理注排水 ;水库、湖泊等大水面水质改良的主要措施是引淡水和增施肥料 (有机肥和化肥 )。 相似文献
11.
水质报表是水环境监测领域内系统的重要组成部分,为加快水质报表的开发,增强水质报表的可维护性,设计独立于系统并且符合水质报表特性的报表工具。该报表工具分为报表设计器和报表服务器两部分,设计器提供可视化的报表编辑界面,允许用户自己设计报表函数,服务器负责报表的调用和解析并且采用缓存机制提高报表的运行效率,将该报表工具应用于水质环境监测及分析系统以验证其实用性,结果证明,该水质报表工具具有较高的灵活性和可扩展性。 相似文献
12.
介绍了塔城市喀浪古尔水库的基本情况,并对喀浪古尔水库水质调查,分析纳污情况,从保护备用水源,减少农村生活污染、农业污染,加强周边保护、开发协调管理等方面探讨了加强水库防范治理的措施. 相似文献
13.
Almost half (354) of all fish kills (805) in South Carolina, USA, between 1978 and 1988 occurred in the coastal zone. These
kills were analyzed for causative, spatial, and temporal associations as a distinct data set and as one integrated with ambient
water quality monitoring data. Estuarine kills as a result of natural causes accounted for 42.8% followed by man-induced (35.1%)
and undetermined causes (22.1%).
Although general pesticide usage was responsible for 53.9% of man-induced kills, weed control activities around resorts and
municipal areas accounted for slightly more kills (20.9%) than did agricultural (19.8%) or vector control (13.2%) uses. A
dramatic decline in agricultural-related kills has been observed since 1986 as the integrated pest management approach was
adopted by many farmers. When taken with the few kills (12.0%) resulting from wastewaters, this suggests that these two land-use
activities have been successfully managed via existing programs (IPM and NPDES, respectively) to minimize their contributions
to estuarine fish kills.
Ambient trend monitoring data demonstrated no coastal-wide dispersion of pesticide pollution. These data confirmed the nature
of fish kills to be site-specific, near-field events most closely associated with the contiguous land-use practices and intensities.
Typically, fish kill data are considered as event-specific data limited to the bounds of that event only. Our analysis has
shown, however, that a long-term data set, when integrated with ambient water quality data, can assist in regulatory and resource
management decisions for both short- and long-term planning and protection applications. 相似文献
14.
根据绵阳市环境监测站计量认证工作实践,着重探讨了计量认证工作转版后,环境监测实验室质量体系的建立、维护、管理,以及该质量体系对规范实验室检测工作和全体人员行为达到质量目标的重要作用。 相似文献
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16.
Potential Impacts of Stormwater Runoff on Water Quality in Urban Sand Pits and Adjacent Groundwater1
Donald O. Whittemore 《Journal of the American Water Resources Association》2012,48(3):584-602
Whittemore, Donald O., 2012. Potential Impacts of Stormwater Runoff on Water Quality in Urban Sand Pits and Adjacent Groundwater. Journal of the American Water Resources Association (JAWRA) 48(3): 584-602. DOI: 10.1111/j.1752-1688.2011.00637.x Abstract: Entrance of stormwater runoff into water-filled pits and adjacent aquifers is a contamination concern. The water and sediment quality in several sand pits and surrounding groundwater in Wichita, Kansas, were studied to comprehensively address stormwater runoff impact. The pits are used for residential development after sand and gravel mining. Water samples were analyzed for inorganic constituents, bacteria, and 252 organic compounds, and pit sediments for inorganic components and 32 organic chemicals. Although many pesticide and degradate compounds were found in the pit and well waters, none of these chemicals exceeded existing health levels. Other organic contaminants were detected in the waters, with those exceeding health levels at one site attributed to an undiscovered groundwater contamination plume and not to stormwater runoff. Persistent insecticides and polychlorinated biphenyls detected in sediment of two pits are related to the age of residential development. The concentration distributions of pesticides and other organics at most of the sites, as well as iron, manganese, and ammonia patterns in downgradient well waters relative to upgradient well and pit waters, indicate that groundwater quality at the sites is affected by contaminants entering the pit surface waters. Thus, although current stormwater runoff does not appear to have contaminated sand-pit water and adjacent groundwater above health levels, the data show that the potential exists if stormwater became polluted. 相似文献
17.
Prakash Basnyat Lawrence Teeter B. Graeme Lockaby Kathryn M. Flynn 《Environmental management》2000,26(2):153-161
In this study, water quality and basin characteristics data from different basins of the Fish River basin, Baldwin County,
Alabama, were used to develop a valuation model. This valuation model is based on the effectiveness of “contributing zones”
identified and delineated using methods described by Basnyat and others (Environmental Management]1999] 23(4):539–549). The “contributing zone” delineation model suggests that depending on soil permeability, soil moisture,
depth to water table, slope, and vegetation, buffer widths varying from 16 m to 104 m must be maintained to assimilate or
detain more than 90% of the nitrate passing through the buffers. The economic model suggests the value of retiring lands (to
create the buffers) varies from $0 to $3067 per ha, depending on the types of crops currently grown. The total value of retiring
all areas identified by the contributing zone model is $1,125,639 for the study area. This land value will then form the basis
for estimates of the costs of land management options for improving (or maintaining) water quality throughout the study area. 相似文献
18.
A water quality index expressed as a single number is developed to describe overall water quality conditions using multiple water quality variables. The index consists of water quality variables: dissolved oxygen, specific conductivity, turbidity, total phosphorus, and fecal coliform. The objectives of this study were to describe the preexisting indices and to define a new water quality index that has advantages over these indices. The new index was applied to the Big Lost River Watershed in Idaho, and the results gave a quantitative picture for the water quality situation. If the new water quality index for the impaired water is less than a certain number, remediation—likely in the form of total maximum daily loads or changing the management practices—may be needed. The index can be used to assess water quality for general beneficial uses. Nevertheless, the index cannot be used in making regulatory decisions, indicate water quality for specific beneficial uses, or indicate contamination from trace metals, organic contaminants, and toxic substances. 相似文献
19.
随着近年工业的发展,工业对电需求量急剧增加。永定县小水电站无节制开发,已对永定河水体造成一定的污染。监测结果表明,小水电站所在的河段水质比永定河其它断面污染严重,已经满足不了永定水环境功能区划的要求。 相似文献
20.
水污染防治规划理论方法综述 总被引:2,自引:0,他引:2
我国的水污染防治规划工作起于20世纪70年代,经过几十年的发展,目前已初成体系,一些成熟的规划方法得到了较为广泛的应用。然而传统方法本身的缺陷、水环境新问题的提出、计算机技术的发展都要求和促使更多新理论方法应用到实践中来。本文在回顾我国水污染防治规划的发展历程和现有规划方法的基础上,对水污染防治规划理论方法的发展趋势进行了展望。 相似文献