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211.
A series of terms has been used to describe corporate environmental activities: waste management/waste minimization, pollution prevention, environmental excellence. Each has a different definition and comprises different activities, yet they represent a continuum of environmental response and improvement. This article considers the characteristics of each activity and the necessary balance among internal and external concerns that corporations seek as they progress toward environmental excellence in a competitive business climate.  相似文献   
212.
The economic inputs and outputs for the Possum Point Biological Station in Belize during 1990–1992 are described to illustrate some aspects of an ecotourism operation. Eight hundred fifty-four people in 59 groups visited Possum Point during the study period to tour rain forests, estuaries, and coral reefs. The economic input to Possum Point from these groups increased from $74,552 in 1990 to $166,268 in 1992. Outputs were for license fees, capital improvements, goods and services, labor, fossil fuels, and development of a historic sugar mill site. An annual donation was also made to a scholarship fund for local Belizean students. The net cash balance of income and outputs changed from negative (−$6678) in 1990 to positive (+$4811) in 1992, suggesting development of the economic operation. Possum Point meets the economic criteria for ecotourism by feeding back some tourist monies for community and environmental support, particularly donations for the sugar mill site and the scholarship fund. Most of the outputs from Possum Point (about 80%) were retained in the local economy through employment and purchases, which have a positive influence on the local community. We conclude that ecotourism operations, such as Possum Point, offer important sustainable development opportunities for Belize.  相似文献   
213.
The effects of trampling on the coral communities of the outer reef flat and reef crest were investigated at Heron Island at the southern end of the Great Barrier Reef. Eighteen months of trampling at various intensities increased the percentage cover of unoccupied substrate and the cover of mobile rubble. The morphology of the coral was the most important feature relating to trampling resistance. Branching corals were reduced on the outer reef flat, and most broken branches were recorded in the initial phases of the experiment. The reef crest was much more resistant.A short-term trampling experiment showed that trampling detached a greater mass and larger fragments of coral on the outer reef flat than on the reef crest. Further trampling reduced the sizes of the detached fragments on the outer reef flat. A drift experiment indicated that greatest movement of fragments occurred on the reef crest and here the largest fragments moved greater distances.We concluded that all habitats would be changed by reef walking and that by one measure the outer reef flat was 16 times more vulnerable than the reef crest. The routes taken by reef walkers need to be chosen in relation to the trampling resistance of the habitat.  相似文献   
214.
The applicability of the Habitat Evaluation Procedure (HEP) was assessed for several nongame bird species in the central Adirondack Mountains of New York. Measures for 24 avian species and 33 associated habitat variables were collected during the summers of 1985 and 1986. The accuracy of four published Habitat Suitability Index (HSI) models was examined: pileated and downy woodpeckers, black-capped chickadee, and veery. Chickadee and veery models were judged successful and were then used to predict habitat quality for respective avian foragingguild members. The HSI model/guild approach provided poor predictors of habitat quality for ubiquitous and uncommon species. Information on relative abundance within the geographic region and specific cover types must be included when designing habitat evaluations using the guild approach.  相似文献   
215.
ABSTRACT: Results from five different test systems, which include a wide range of optical conditions, indicate credible estimates of the values of the absorption and scattering coefficients can be calculated from paired measurements of Secchi disc transparency and the diffuse attenuation coefficient. The diagnostic utility of the estimates in identifying components and processes that regulate light penetration is demonstrated for three different cases. The simple estimation technique is valuable in the analysis of existing data bases that lack comprehensive optical information to develop and evaluate alternate models for light penetration and to establish the experimental needs of future field programs to support lake management efforts.  相似文献   
216.
This study examined the predictive contribution of occupational and marital stress to the development of symptomatolgoy, affective disorder, and alcohol-related problems in a sample of 325 male power plant employees interviewed at baseline and one-year follow up. After controlling for known clinical and social risk factors, we found statistically significant predictive effects of job demands on affective disorder and job decision latitude on alcohol problems. In addition, the specific combination of high job demands with low decision latitude was important in predicting the occurrence of alcohol problems. Marital stress was not predictive of poorer mental health. The analyses provided only minimal support for a stress-buffering rote of social support.  相似文献   
217.
The Quality–Assessed Agrichemical Contaminant Database for Nebraska Ground Water is a unique repository of nitrate and pesticide data collected by federal, state, and local agencies. Each contaminant concentration in the database has been evaluated based upon well–defined criteria that address completeness of the well–attribute data, analytical method and field and laboratory quality control practices and assigned to one of five quality levels. The quality assessment level always accompanies the contaminant concentration so that the end–user knows the quality assurance effort expended in the acquisition of the data, can select comparable data, and choose data whose quality assurance effort is commensurate with project objectives. The database can be viewed and queried on–line; downloaded in its entirety; or imported to a spreadsheet or a geographic information system. Setting criteria for data quality and assessing the level of quality have resulted in significant increases in the percentages of high quality (Levels 3–5) nitrate and pesticide data. These high quality data presently constitute 52% of the nitrate and 55% of the pesticide data.  相似文献   
218.
A network of five water quality monitoring stations has been established in Long Island Sound, measuring temperature, salinity, and dissolved oxygen since 1999. The stations are located in areas of extreme water quality degradation (western Long Island Sound) as well as in pristine areas (eastern Long Island Sound). The data from these stations are collected every 15 minutes and posted to the project web site in real time as provisional data. After subsequent quality assurance procedures, the data are archived to the project File Transfer Protocol (FSP) site for downloading by the user community. The network of stations is in part supported logistically by a number of partners, including state and local agencies, schools, and non-governmental organizations. Data from the monitoring programs of some of these partners are also published to the project website providing a more comprehensive and complete picture of the status of the Sound than can be provided independently. This repository of information is used by marine educators, resource managers, scientists, and the general public, each with a different end purpose. We use the data from two of the stations to show that these high frequency time series measurements can be used to complement and enhance other monitoring programs within the Sound, documenting in greater detail the occurrence and duration of hypoxic events.  相似文献   
219.
The resolution of conflicts arising from differing values and water uses requires technical information and negotiating skills. This article outlines the Instream Flow Incremental Methodology (IFIM), developed by the US Fish and Wildlife Service, and demonstrates that its use to quantify flows necessary to protect desired instream values aids negotiation by illustrating areas of agreement and possible compromises between conflicting water interests. Pursuant to a Section 404 permit application to the US Army Corps of Engineers made by City Utilities of Springfield, Missouri, in 1978, IFIM provided the means by which City Utilities, concerned with a secure water supply for a growing population, and those advocating instream values were satisfied that their requirements were met. In tracing the 15-month process, the authors conclude that the application of IFIM, as well as the cooperative stance adopted by the parties involved, were the key ingredients of the successful permit application.  相似文献   
220.
One central issue affecting the health of native fish species in the Pacific Northwest is water temperature. In situ observation methods monitor point temperatures, while thermal infrared (TIR) remote sensing captures spatial variations. Satellite‐based TIR sensors have the ability to view large regions in an instant. Four Pacific Northwest river reaches were selected to test the ability of both satellite‐based and moderate resolution aircraft‐based TIR remote sensing products to measure river temperatures. Images with resolutions of 5, 15, and 90 meters were compared with instream temperature observations to assess how along stream radiant temperatures are affected by resolution, reach width, and sensor platform. Where the stream reach can be resolved by the sensor, all sensors obtain water temperatures within ±2°C of instream observations. Along stream temperature variations of up to ±5°C were also observed. Trends were similar between two sets of TIR images taken several hours apart, indicating that the sensors are observing actual temperature patterns from the river surface. If sensor resolution is sufficient to obtain fully resolved water pixels in the river reach, accurate temperatures and spatial patterns can be observed. The current generation of satellite‐based TIR sensors is, however, only able to resolve about 6 percent of all Washington reaches listed as thermally impaired.  相似文献   
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