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601.
National park resource management planning requires ecological information describing the objectives to be achieved. This information must be quantitative and unambiguous. Since most acts creating United States national parks, beginning with the Yellowstone National Park Act of 1872, specify that these parks should be maintained in a natural condition, resource management objectives for each national park must be defined in terms of quantitative standards of naturalness. Such quantitative standards of naturalness do not yet exist for any national park in the United States. Although this article focuses on US national parks, the same problem exists in national parks, reserves, and wilderness areas throughout the world. The physical evidence needed to develop quantitative standards of naturalness is rapidly disappearing because of the effects of management fires, wildfires, decomposition, successional changes, and other disturbances. Therefore, a nationwide rescue ecology program is recommended to recover as much remaining ecological information as possible before it is lost. This information is essential for developing quantitative standards to restore naturalness to national parks. 相似文献
602.
Sandra L. Kirmeyer 《Journal of environmental psychology》1985,5(4):355-372
In the course of studying police dispatchers, five observers recorded the reactions of the employees (N = 37) to their presence throughout the work shift on three separate occasions. Four major research questions were considered: (a) extent of reaction, (b) relationship between interactions with the observer and changes in employees' work activities, (c) independence of verbal and nonverbal behavioral reactions, and (d) adaptation. On average, subjects or other employees initiated 10 interactions per hour with observers. These interactions were classified as subject-initiated (a) verbal, content related to research procedures; (b) verbal, non-research-related in content; (c) nonverbal only or (d) other employee-initiated verbal comment. Interaction with the observer was not related to the amount of work the subject did. Subjects' nonverbal and verbal responses were unrelated to each other as well as to the verbal responses of other employees. A priori expectations concerning adaptation to observation were tested with a 3 × 3 (segment by day) repeated-measures factorial design. Significant adaptation (P < 0·01) occurred within and between days in subjects' comments about research procedures and all comments from other employees. However, other behaviors showed with no evidence of adaptation or actual increases. The implications of these findings for measuring reactivity and deciding when adaptation has occurred are discussed. 相似文献
603.
Lowell E. Keup 《Journal of the American Water Resources Association》1985,21(2):291-296
Using data related to stream order and the morphological characteristics associated with streams of different discharge rates, an estimate of the river resources of the United States is made. The national totals are: 3,200,000 miles total length of rivers; 15,000 square miles of river surface; and 29 cubic miles of water stored in river channels. Using the same techniques, more exact estimates may be made for individual river basins. Suggestions are given for application of the techniques and river data in the management of water resources. 相似文献
604.
Steven R. Abt Rodney J. Wittier James F. Ruff Mohammad S. Khattak 《Journal of the American Water Resources Association》1988,24(6):1193-1200
ABSTRACT: A series of flume tests were conducted to determine the flow resistance of angular shaped riprap in steep channels. Flow resistance was expressed in terms of the Darcy-Weisbach friction factor and the Manning's roughness coefficient. Prototype channels of 4 ft. (1.2 m) and 12 ft. (3.7 m) in width were constructed at slopes ranging from 0.01 to 0.20. The channel beds were comprised of angular riprap of median diameters of 1, 2, 4, 5, and 6 inches (2.59, 5.59, 10.41, 12.95, and 15.75 cms). The Darcy-Weisbach and Manning's coefficients were determined for each test condition prior to bed failure. The resulting Darcy-Weisbach coefficients were related to the channel energy gradient and the bed relative submergence for highly turbulent flow. Also, Manning's roughness coefficients were related to the product of the median stone diameter and energy gradient. Because of the angular shape of the riprap and the wedging and/or packing of the bed materials, the resistance to flow was found to exceed the flow resistance values predicted by previous studies. Expressions were presented for estimating the resistance to flow for angular riprap in steep channels. 相似文献
605.
Trevor C. Hughes 《Journal of the American Water Resources Association》1984,20(5):739-746
Although the volume of potable water used at recreation developments is minor relative to total regional water use, very high quality is required and the source is often of limited capacity, such as a mountain spring or small local aquifer. Frequent confrontations between developers and regulatory agencies result from claims by developers that water demand will be very small while regulators tend to treat such developments the same as municipal residence. Almost no published data base exists for resolving such conflicts. Included here are: 1) Water use measurements of various peak period durations (seasonal, monthly, daily, and instantaneous) at several types of recreational developments in Utah and Wyoming (mountain cabins, both ski- and water-based condominiums, and recreation vehicle campgrounds), 2) statistical (frequency) analysis of the data and a comparison with municipal demands in the same region, and 3) analysis of occupancy rates at the various categories of developments. 相似文献
606.
采用单因子评价法和Spearman秩相关系数评价法,对2008—2017年苏州沿江三市(张家港、常熟、太仓)主要入江支流水质变化特征进行分析。结果表明,苏州沿江三市的入江支流水质总体好转,张家港市入江支流水质明显好转,太仓市入江支流水质有所好转,常熟市入江支流水质总体保持稳定;NH3-N、COD和BOD5是影响入江支流水质的主要污染指标;主要污染指标优Ⅲ类比例总体呈上升趋势,但2014—2016年有所下降。2017年沿江三市入江支流水质总体处于Ⅲ类水平。 相似文献
607.
608.
环境在线监测监控管理与发布系统 总被引:13,自引:1,他引:13
阐述了省级环境在线监测监控管理与发布系统的组成及功能特点,介绍了采用GPRS无线数据传输方式,对水、气、污染源等环境在线监测自动化系统进行数据采集、统计与GIS发布的实现方式,指出其具有传输速率高、延时小、实时性强、建设方便、费用低廉等显著优点。 相似文献
609.
610.
James G. Thompson Michael Parker William Templin Robert R. Reynolds 《Journal of the American Water Resources Association》1993,29(3):425-433
ABSTRACT: This paper reviews the processes that occurred during an application of the Metropolitan Water District (MWD)-MAIN water use forecasting system for the City of Salinas, California. The review includes an analysis of sources of available data, methods for estimating input data, calibration, and verification of the MWD-MAIN System, and an evaluation of the reliability of system output. We found that inexperienced users can have difficulty understanding the level of skill, knowledge, and amount of data that are required to produce reliable forecasts. Some of the issues associated with application of the MWD-MAIN System include the following:
- ? All input data needed for accurate forecasts simply are not available for many cities and towns.
- ? The data requirements are more extensive than many users anticipate.
- ? Substantial requirements for manipulation of input data produces opportunity for error that creates major time demands in troubleshooting.
- ? Calibration and verification for specific uses can be substantially more difficult than is readily apparent from the guidance manual.
- ? Independent validity checks need to be done to validate system output.
- ? If specified calibrating procedures do not produce reasonable results, reestimating slope coefficients is an option, but this requires resources and expertise that can easily exceed the limits of most users.