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11.
Thomas Hruby 《Environmental management》1999,23(1):75-85
/ Many methods have been developed over the last two decades to provide information about wetland functions, but there has been little discussion of the models and algorithms used. Methods for generating information about wetlands were analyzed to understand their similarities, differences, and the type of information provided. Methods can first be grouped by the type of information they provide-classifications, characterizations, ratings, assessments, and evaluations. Methods that characterize, rate, or assess wetlands may generate information using one of two conceptual approaches-logic and mechanistic. Most methods that generate a numeric assessment of performance or value of wetland functions rely on the mechanistic approach to constructing models. Rapid assessment methods based on mechanistic models, however, do not assess the rates or dynamics of ecological processes occurring in wetlands. Rather, they provide a clear and concise way of organizing our current, and often subjective, knowledge about wetland functions. This is one limitation of current methods that is often misunderstood both by wetland managers and the scientific community. The advantages and limitations of the assumptions and the computational elements inherent in these approaches are discussed to provide wetland managers and regulators a better understanding of the information they are using. KEY WORDS: Wetlands; Functions; Assessment; Models; Methods 相似文献
12.
Christopher S. Davies 《Environmental management》1992,16(3):323-333
Oak wilt disease, for which there is no known cure, is one of the most destructive tree killers in the United States today.
This analysis reports on the patterns of disease transmission, along with the methods of treatment used to suppress the severity
of the pathogen's attack on trees in central Texas. The practical problems inherent in the linkage between people and their
relationship with this environmental disorder are addressed. The environmental controls implemented have application to other
areas of the United States and western Europe, where tree species are subject to infections. 相似文献
13.
The US Army Land Condition-Trend Analysis (LCTA) program is a standardized method of data collection, analysis, and reporting
designed to meet multiple goals and objectives. The method utilizes vascular plant inventories, permanent field plot data,
and wildlife inventories. Vascular plant inventories are used for environmental documentation, training of personnel, species
identification during LCTA implementation, and as a survey for state and federal endangered or threatened species. The permanent
field plot data documents the vegetational, edaphic, topographic, and disturbance characteristics of the installation. Inventory
plots are allocated in a stratified random fashion across the installation utilizing a geographic information system that
integrates satellite imagery and soil survey information. Ground cover, canopy cover, woody plant density, slope length, slope
gradient, soil information, and disturbance data are collected at each plot. Plot data are used to: (1) describe plant communities,
(2) characterize wildlife and threatened and endangered species habitat, (3) document amount and kind of military and nonmilitary
disturbance, (4) determine the impact of military training on vegetation and soil resources, (5) estimate soil erosion potential,
(6) classify land as to the kind and amount of use it can support, (7) determine allowable use estimates for tracked vehicle
training, (8) document concealment resources, (9) identify lands that require restoration and evaluate the effectiveness of
restorative techniques, and (10) evaluate potential acquisition property. Wildlife inventories survey small and midsize mammals,
birds, bats, amphibians, and reptiles. Data from these surveys can be used for environmental documentation, to identify state
and federal endangered and threatened species, and to evaluate the impact of military activities on wildlife populations.
Short- and long-term monitoring of permanent field plots is used to evaluate and adjust land management decisions. 相似文献
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15.
Fluoridated salt is an effective method to reduce dental decay in the population at large, in particular in settings where the more frequently used method of fluoridated water is not feasible due to unreliable water supplies. A salient problem of regular dosage and monitoring of fluoride in salt is its variable level at the industrial level. To evaluate the relative advantages of the present monitoring method used in Mexico, samples of domestic fluoridated salt were analysed by two comparative methods to determine their fluoride content. One of the methods employed was the relevant Mexican Offcial Norm (based on an acetic acid, sodium chloride, trans-1,2-diamine, cyclohexane N,N,N',N' tetracetic acid buffer solution) and the other was an alternative electrochemical methodology (based on an acetic acid, sodium chloride, sodium citrate buffer solution). The cost of the chemicals involved and simplicity of the alternative method, along with the equivalent precision of its results, makes it an interesting choice for the large scale analysis of fluoridated salt. 相似文献
16.
环境风险预警方法与应急成套装备的应用展望 总被引:1,自引:0,他引:1
介绍了环境风险预警方法建立的环境风险预警指标体系、环境风险源管理平台、环境风险源风险评估技术方法以及模块式应急成套装备的技术特点等;分析了环境风险预警方法与应急成套设备在危险化学品环境风险与应急管理,在区域大气环境挥发性有机污染物(VOCs)监控预警等方面的实际需求。面临现实的环境风险状况从环境风险防控与应急工程技术研究中心建设角度提出了需进一步完善、开发的环境风险预测预警技术与应急成套装备等新思路。 相似文献
17.
为推进农村环境综合整治工作,针对环办[2010]136号规定评估指标体系应用过程中遇到的问题,采取定义与计算、定性与定量结合的方法,对规定评估指标进行定义、明确赋分依据,确定不同完成程度下的赋分标准和计算方法,为环境成效评估提供科学、准确、可行、实用的赋分依据和办法。 相似文献
18.
In 1991, provisions for environmental impact assessment in New Zealand were changed significantly with the enactment of the
Resource Management Act. Among other provisions, this act requires consideration of cumulative impacts in environmental assessment
activities undertaken by planners in newly created regional authorities and district and city councils. The institutional
context in which the act is being implemented offers both opportunities and constraints to cumulative impact assessment. A
lack of methods for CIA is a recognized problem. However, methods that have been developed for environmental impact assessments
can be modified to incorporate second-, third-, and fourth-order impacts as well as to identify the direction and magnitude
of additive and synergistic impacts. Layered matrices and combined networks are examples of such methods. While they do not
allow for scientific prediction, they do provide the practitioner with the ability to consider the cumulative impacts of decisions.
This is crucial in New Zealand, where statutory requirements are ahead of established methodologies. 相似文献
19.
利用微生物法对红霉素膜浆中的红霉素药物残留量进行测定,红霉素残留量为265.88μg/mL。再通过调节pH值不同对膜浆残留红霉素的降解进一步研究。利用盐酸将膜浆的pH值调到2时,残留红霉素浓度为15.03μg/mL;降解率为94.35%。 相似文献
20.
通过渗灌、滴灌、沟灌3种灌溉方法对保护地土壤pH、全盐含量及水溶性离子组成的影响,探讨了3种灌溉方法在保护地土壤酸化、盐化过程中的演化规律.结果表明:渗灌、滴灌、沟灌:3种处理方法中滴灌处理比渗灌处理和沟灌处理效果更好,表层水溶性盐分和硝酸盐积累较轻,酸化较轻,有利于土壤环境的可持续性发展和有效地保护土壤资源. 相似文献