With increasing use of herbicides there has been growing concern that spray drift from treated land will affect vegetation on adjacent nature reserves and other areas of high conservation interest. A preliminary attempt was made to assess this risk by placing a range of native plant species at different distances downwind from standardised drift events and assessing lethal effects and sublethal damage. Five herbicides were tested: asulam, 'Finesse' (chlorsulfuron + metsulfuron-methyl), glyphosate, MCPA and mecoprop. Applications were made at the appropriate time of years for each herbicide (autumn, spring and summer), and at both low and high wind speeds. The maximum safe distance at which no lethal effects were found was 6 m from the sprayer, but for most herbicides the distance was 2 m or less. Generally, damage symptoms were found at greater distances than lethal effects, but in most cases there was rapid recovery by the end of the growing season. These observations are consistent with drift-deposition models, in which the fallout of herbicide droplets has been measured. It is suggested that buffer zones surrounding nature reserves should be in the order of 5-10 m for ground sprayers to minimise the risk of herbicide impacts on these habitats. 相似文献
Changes in concentrations of soluble reactive phosphorus (SRP), excess partial pressure of carbon dioxide (EpCO2), and chlorophyll-a were examined for two rivers in the in the upper Thames catchment: the main river Thames at Wallingford and a chalk stream tributary, the River Kennet. Sampling began in the spring of 1997 and has covered extremes in river flow conditions. During the sampling period there was a dramatic reduction in phosphorus (P) inputs from the introduction of effluent P-treatment at sewage treatment works, as a result of the EU Urban Wastewater Treatment Directive. Despite major reductions in baseflow SRP concentrations in the River Kennet, from around 700 μg-P L-1 to around 100 μg-P L-1, observations of aquatic plant communities indicate overall degradation in ecological quality since effluent P-treatment was introduced. The degradation was associated with a spring and summer decline in growth of Ranunculus, a macrophyte of high conservation value in chalk streams, particularly from 2000 onwards, linked to shading by epiphytic algae. Although the EpCO2 records indicate a reduction in primary productivity since effluent P-treatment, the River Kennet may have become more sensitive to epiphyte blooms. Episodes of epiphyte proliferation appear to be linked temporally to small increases in SRP concentrations (typicallyabove a 100 μg-P L-1 threshold) under summer baseflow conditions. The in-stream system is highly complex and individual processes and causality are difficult to resolve, particularly given changes in river flows linked to background climatic variability and limited availability of biological data. This study demonstrates the need for integrated long-term biological and chemical monitoring of river systems subject to major perturbations to assess timescales required to produce new dynamic equilibria in ecosystem response. 相似文献
Historically, unpleasant odors have been considered warning signs or indicators of potential risks to human health but not necessarily direct triggers of health effects. However, citizen complaints to public health agencies suggest that odors may not simply serve as a warning of potential risks but that odor sensations themselves may cause health symptoms. Mal-odors emitted from large animal production facilities and wastewater treatment plants, for example, elicit complaints of eye, nose, and throat irritation, headache, nausea, diarrhea, hoarseness, sore throat, cough, chest tightness, nasal congestion, palpitations, shortness of breath, stress, drowsiness, and alterations in mood. There are at least three mechanisms by which ambient odors may produce health symptoms. First, symptoms can be induced by exposure to odorants (compounds with odor properties) at levels that also cause irritation or other toxicological effects. That is, irritation--rather than the odor--is the cause of the health symptoms, and odor (the sensation) simply serves as an exposure marker. Second, health symptoms from odorants at non-irritant concentrations can be due to innate (genetically coded) or learned aversions. Third, symptoms may be due to a co-pollutant (such as endotoxin) that is part of an odorant mixture. Objective biomarkers of health symptoms must be obtained, however, to determine if health complaints constitute health effects. One industry that is receiving much attention, worldwide, related to this subject is concentrated animal production agriculture. Sustainability of this industry will likely necessitate the development of new technologies to mitigate odorous aerial emissions. Examples of such "environmentally superior technologies" (EST) developed under the initiative sponsored through agreements between the Attorney General of North Carolina and Smithfield Foods and Premium Standard Farms are described. 相似文献
This article discusses the current framework of coastal decision making which tends to exclude participation by individuals and those without a strong institutional representation. A distinction is drawn between institutional and local stakeholders to illustrate weaknesses in the existing decision framework. It is argued that particularly in the coastal environment, the relationship between changes in physical form and changes in social welfare is critical to understanding how decision making may engage more fully with local stakeholders and ultimately improve decision outcomes. A reordering of stakeholder engagement in decision systems at the coast is proposed and a framework is outlined which enhances the capacity of local stakeholders to influence decision making. 相似文献
Tenant participation in council housing management; Housing Development.
Directorate Occasional Paper 2/77, DoE London, 1977.
Getting tenants involved: a handbook on systems of tenant participation in housing management; DoE London, 1977.
La politica dei servizi tra razionalizzazione e rinnovamento
Alberto L'Abate (1978)
Marsilio Editori, Padova, pp. 316
Handbook for Environmental Planning: the social consequences of environmental change.
J. McEnvoy & T. Dietz (1977)
New York, J. Wiley, pp. 323. Price £15.50
Planning and Urbanism in China
Progress in Planning Vol. 8, Part 2, Fo. 1 N. Jeffrey and M. Caldwell, pp. 97–182, 1977
Pergamen, £4.00
The European Community's Regional Fund
Ross B. Talbot
Progress in Planning, Vol. 8, Part 3, pp. 183–281
Pergamon Press, 1977
Providing the Posh Words
W. Hampton, DoE
1978. £1.50. 60pp.
Four Titles on Conservation
A Critical Bibliography of Building Conservation. John F. Smith. Mansell, London 1978. 207 pages including index. Hard back, £12.90.
Conservation and Planning. Alan Doby. Hutchinson — The Built Environment. 1978. 173 pages. Some illustrations. Paper back, £3.25.
A Study in Conservation. Winston Barnett and Cyril Winskell. Oriel Press, 1977. 45 pages, in English, French and German. Illustrated. Paper back, £3.75.
Interpreting the Conserved Environment. Working Paper No. 29. Brian Goodey. Oxford Polytechnic Department of Town and Country Planning, 1977. 65 pages. Paper back, not priced.
ABSTRACT: Spatial distribution of soil and water properties and the correlations between them and crop yield were determined for a natural rainfall environment. Hydraulic conductivity, soil texture, water retention, and soil-water flux were variables used to investigate their relationship to crop yield using multiple regression techniques. Variations in crop yields on a watershed with a 3 to 4 percent slope and moderately erosive soils were related to soil-water characteristics and soil properties along slope and with depth. Climatic conditions to sustain crop growth and yield ranged from inadequate soil water in 1983 to adequate soil water in 1984. Crop yield was predicted with models using both available and measured soil-water content. Available water content provided a better model for the prediction of water yield and does not require field measurements of actual soil-water content. Soil water holding capacity was more significant for predicting crop yield in soils with moderate to high silt content than infiltrability of water into the soil. 相似文献
Shadrach Woods, The Man in the Street, Harmondsworth, Penguin, 1975
W. Houghton Evans, Planning Cities, London, Lawrence & Wishart, 1975, £7
R. Taylor, M. Cox & I. Dickens eds., Britain's Planning Heritage, London, Croom Helm for The Royal Town Planning Institute, 1975. £5.75 (hardcover) £3.50 (paperback)
Development Plan Evaluation and Robustness: Application of an Analytical Programme and a Review of Measures of Performance, Department of the Environment Research Report 5 Local Government Operations Research Unit Report C217, 1976. Gratis.
J. Appleton, The Experience of Landscape, London, John Wiley, 1975
J. D. Hunt & P. Willis eds., The Genius of the Place: The English Landscape Garden 1620–1820, London, Paul Elek, 1976. £12.50
N. Pevsner, Staffordshire, Harmondsworth, Middx., Penguin Buildings of England Series, 1974, £3.50 (hardcover)
R. Bailey & M. Brake eds., Radical Social Work, London: Edward Arnold, 1975. £4.25 (hardcover) £1.95 (paperback)
and
The Use of Action Research in Developing Urban Planning Policy: Report of Colloquium, Bristol, June 1975 London, Department of the Environment, 1975.
M. Harloe, Swindon: A Town in Transition, London, Heinemann for the centre for Environmental Studies, 1975.
D. W. Pearce ed., The Economics of Natural Resource Depletion, London, Macmillan, 1975.
J. B. Goddard, Office Location in Urban and Regional Development
B. Fullerton, The Development of British Transport Networks
B. T. Robson, Urban Social Areas
P. L. Knox, Social Well‐Being: A Spatial Perspective
Four volumes in the Theory and Practice in Geography series, edited by J. W. House, A. S. Gouldie & J. H. C. Patten and published by Oxford University Press, 1975. All paperback at £0.90.
James A. Swan & William B. Stapp eds., Environmental Education: Strategies Toward a More Liveable Future, Halstead Press — John Wiley, 1974.
A. G. Wilson & M. J. Kirkby, Mathematics for Geographers and Planners, Oxford: Clarendon Press, 1975 相似文献
ABSTRACT: Water quality impacts from two types of low water stream crossings (LWSC) were examined on the military training lands at Fort Riley, Kansas. The LWSC project was developed to enhance military training as well as improve the water quality of the streams. Water quality impacts of low water fords were quantified and compared to determine the effects of using rock to harden earthen fords. Both earthen and rock hardened low water fords were tested for the impact on stream turbidity, total solids, total dissolved solids, total suspended solids, and settleable solids. Results indicate hardening earthen fords with rock can significantly reduce water quality degradation caused by vehicle movement over the ford. Turbidity caused by vehicles crossing earthen and hardened fords was nearly sixteen times higher for earthen fords. Likewise, total solids, total dissolved solids, and total suspended solids concentrations were lower for hardened crossings. Total solids concentrations from earthen fords were nearly twelve times higher than concentrations from hardened fords. Hardening earthen fords not only provides the military with a more stable stream crossing for its soldiers to use, it decreases water quality degradation and improves local stream ecology. Recommendations for constructing rock hardened LWSC are given. 相似文献