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391.
Mike R. Scarsbrook Chris G. McBride Graham B. McBride Graham G. Bryers 《Journal of the American Water Resources Association》2003,39(6):1435-1447
ABSTRACT: Associations between the El Nino Southern Oscillation (ENSO) climate pattern and temporal variability in flow and 12 water quality variables were assessed at 77 river sites throughout New Zealand over a 13‐year period (1989 through 2001). Trends in water quality were determined for the same period. All 13 variables showed statistically significant linear regression relationships with values of the Southern Oscillation Index (SOI). The strongest relationships were for water temperature (mean R2= 0.20), dissolved reactive phosphorus (0.18), and oxidized nitrogen (0.17). The association with SOI varied by climate region. The observed patterns were generally consistent with known ENSO effects on New Zealand rainfall and air temperature. Trends in water quality variables for the periods 1989 through 1993, 1994 through 1998, and 1989 through 1998 were reasonably consistent with trends in SOI, even when the influence of river flow was removed from the data. This suggests that SOI effects on water quality are not necessarily a direct consequence of changes in flow associated with rainfall variation. In addition, both Baseline (32 upstream) and Impact (45 downstream) sites showed similar trends, indicating that changes in management were not directly responsible. We conclude that interpretation of long term water quality datasets in rivers requires that climate variability be fully acknowledged and dealt with explicitly in trend analyses. 相似文献
392.
Michael C. Morris 《Journal of Agricultural and Environmental Ethics》2000,13(3-4):205-217
Fly strike is a painful conditioncaused by live maggots eating at the flesh of sheep.Remedies for this disorder are traumatic, with sheepundergoing painful mulesing and tail dockingoperations to protect against flystrike. In an attemptto find control solutions and to understand thedisorder, Australasian researchers increase sheepsuffering by conducting experiments that artificiallyinduce fly strike. Some of these experiments have noapplication in prevention and control of fly strike.Many others could be modified or replaced with lesspainful techniques.Anecdotal evidence through communication withorganic farmers suggests that fly strike is largelypreventable if farmers keep sheep healthy and inspectthem regularly. Some organic farmers have largelyeliminated fly strike from their farm. Investigationson fly strike control using non-intrusive techniquesare also progressing in Australasia and the UnitedKingdom.Since it is possible to conduct useful research andto run profitable farms with little or no fly strike,much of the current management, research and policy onsheep farming is ethically questionable even to thoseholding the moderate view that animals can be used forhuman purposes providing suffering is kept to aminimum. Sheep farmers will need to take animalwelfare problems into consideration. Greatercommunication among researchers needs to be encouragedto prevent unnecessary duplication of experiments.International trade regulations will also need toallow trade barriers based on animal welfareconcerns. 相似文献
393.
Robert M. Hordon 《Journal of the American Water Resources Association》1977,13(5):933-939
ABSTRACT: A growing number of developing communities in New Jersey is planning for an ultimate population that would be supplied by endogenous sources of water. At the state and national level, however, reliance on exogenous sources appears to be in favor. Both viewpoints, of course, recognize that water supply is one of the major critical factors in determining the capacity of a land area to support population. Three planning issues that bear on this endogenous-exogenous source controversy are discussed: 1) deep aquifers which have recharge areas in other political jurisdictions and are therefore regulated by other bodies will not count as an endogenous source, reliance will be placed only on shallow water table aquifers which are recharged by local precipitation; 2) total development of the groundwater resources of a headwaters community could result in severe base flow diminishment, thereby supporting the notion that these communities have a regional responsibility to restrict their growth so as to preserve and protect the water supply for downstream users; and 3) yield decrementing estimates, i.e., how much recharge water is lost to runoff as a consequence of development, are needed in order to assess the magnitude of local water resources. 相似文献
394.
The effect of dairy farming on water quality in New Zealand streams has been identified as an important environmental issue. Stream fencing, to keep cattle out of streams, is seen as a way to improve water quality. Fencing ensures that cattle cannot defecate in the stream, prevents bank erosion, and protects the aquatic habitat. Stream fencing targets have been set by the dairy industry. In this paper the results of a study to identify the factors influencing dairy farmers' decisions to adopt stream fencing are outlined. Qualitative methods were used to gather data from 30 dairy farmers in four New Zealand catchments. Results suggest that farm contextual factors influenced farmers' decision making when considering stream fencing. Farmers were classified into four segments based on their reasons for investing in stream fencing. These reasons were fencing boundaries, fencing for stock control, fencing to protect animal health, and fencing because of pressure to conform to local government guidelines or industry codes of practice. This suggests that adoption may be slow in the absence of on-farm benefits, that promotion of stream fencing needs to be strongly linked to on-farm benefits, and that regulation could play a role in ensuring greater adoption of stream fencing. 相似文献
395.
Nord L. Gale Bobby G. Wixson Michael G. Hardie J. Charles Jennett 《Journal of the American Water Resources Association》1973,9(4):673-688
The New Lead. Belt of southeastern Missouri has recently become the largest lead producing region of the world. The impact of this rapid development on the previously rural and undeveloped region of the Missouri Ozarks is the subject of a continuing interdisciplinary study. Since the industrial development began, there have been a number of nuisance biological blooms in several of the small streams receiving effluent from the mines and mills. The major constituents of the problem algal growths were identified and found to include: Cladophora, Oscillatoria, Mougeotia, Zygnema, Spirogyra, Cymbella, and a variety of other stalked and non-stalked diatoms. Secondary blooms of Sphaerotilus were observed to reach problem proportions in some streams, particularly in the autumn. Finely ground rock flour and mineral particles escaping from tailings dams were found to be trapped by the stream vegetation. Concentrations of lead, zinc, copper, and manganese in the algal and bacterial mats were found to be inversely related to distance downstream from the tailings dams. Consumer organisms, including crayfish, snails, aquatic insects, tadpoles, minnows and larger sunfish were analyzed to determine the extent of dissemination and concentration of the heavy metals through food chains. Preliminary results indicated insignificant concentrations of heavy metals in those consumer organisms studied, though in at least one problem stream the normal consumer organisms mentioned were markedly reduced in numbers. 相似文献
396.
James W. Hornbeck 《Journal of the American Water Resources Association》1975,11(6):1257-1260
ABSTRACT: Experimental cuttings on two small, hardwood-forested watersheds in New England showed that annual streamflow can be increased as much as 41 percent. Most of the increase occurred in summer and early autumn when additional streamflow is most needed. Revegetation caused the annual increases to nearly disappear within 4 years after complete forest clearing. 相似文献
397.
A GIS Approach to Model Sediment Reduction Susceptibility of Mixed Sand and Gravel Beaches 总被引:3,自引:0,他引:3
The morphological form of mixed sand and gravel beaches is distinct, and the process/response system and complex dynamics
of these beaches are not well understood. Process response models developed for pure sand or gravel beaches cannot be directly
applied to these beaches. The Canterbury Bight coastline is apparently abundantly supplied with sediments from large rivers
and coastal alluvial cliffs, but a large part of this coastline is experiencing long-term erosion. Sediment budget models
provide little evidence to suggest sediments are stored within this system. Current sediment budget models inadequately quantify
and account for the processes responsible for the patterns of erosion and accretion of this coastline. We outline a new method
to extrapolate from laboratory experiments to the field using a geographical information system approach to model sediment
reduction susceptibility for the Canterbury Bight. Sediment samples from ten representative sites were tumbled in a concrete
mixer for an equivalent distance of 40 km. From the textural mixture and weight loss over 40 km tumbling, we applied regression
techniques to generate a predictive equation for Sediment Reduction Susceptibility (SRS). We used Inverse Distance Weighting
(IDW) to extrapolate the results from fifty-five sites with data on textural sediment composition to field locations with
no data along the Canterbury Bight, creating a continuous sediment reductions susceptibility surface. Isolines of regular
SRS intervals were then derived from the continuous surface to create a contour map of sediment reductions susceptibility
for the Canterbury Bight. Results highlighted the variability in SRS along this coastline. 相似文献
398.
This paper reviews selected research on classroom and school environments, using a framework that views schools from three perspectives—as places for learning, as places for socialization and as places for psychological development. Studies are included that deal with the impact of noise and classroom design on learning; the relationship between seating position, achievement and status; spatial cognition; the classroom environment and sex role stereotyping; privacy; and density. The need for classrooms to enhance children's feelings of competence, security and self-esteem is also stressed. The goal of the paper is to point out ways in which environmental psychologists can contribute to the improvement of the educational system and to the quality of life in schools. 相似文献
399.
400.
Caralampo Focas 《Journal of Environmental Planning and Management》2017,60(5):901-919
London and New York have often been hailed for their sustainable planning practices. However, when one focuses on the entire city region, there is ever-increasing car-dependent development. This paper focuses on the exurban region of the two cities investigating transport-created CO2 emissions. The research is based on the analysis of data of the National Travel Surveys of Great Britain and the USA through a quantification of personal travel and a top-down estimation of CO2 emissions. It is the exurban region that accounts for the vast majority of CO2 emissions: 77% for London and 87% for New York. In the wider region for both cities there is a policy vacuum and dearth of regional planning mechanisms to deliver policies to reduce CO2 emissions. The paper argues that transport needs to be planned at the city-regional scale. 相似文献