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1.
Formulation of standards of quality in parks and outdoor recreation can be guided by normative theory and related empirical methods. We apply this approach to measure the acceptability of a range of use levels in national parks in Turkey and the United States. Using statistical methods for comparing norm curves across contexts, we find significant differences among Americans, British, and Turkish respondents. In particular, American and British respondents were substantially less tolerant of seeing other visitors and demonstrated higher norm intensity than Turkish respondents. We discuss the role of culture in explaining these findings, paying particular attention to Turkey as a traditional “contact culture” and the conventional emphasis on solitude and escape in American environmental history and policy. We conclude with a number of recommendations to stimulate more research on the relationship between culture and outdoor recreation.  相似文献   

2.
Use of publicly-provided information to promote environmental quality has received somewhat less attention in the environmental management literature than use of other environmental policy tools based on economic incentives such as emissions taxes, subsidies and marketable permits. Yet publicly-provided information may have potential as an environmental policy tool, especially in managing problems of agricultural pollution, due in large part to the existing capability of public information agencies associated with the agricultural research community. Information provided by these agencies is known to be an important factor in decision making in agriculture and may have potential for influencing decisions that relate directly to preserving the integrity of environmental resources. Moreover, this potential may have particular relevance for protecting groundwater quality from agricultural production since the results of contamination are often at least partially internal to the farm decision maker. This paper develops an empirical model to formulate publicly-provided herbicide treatment recommendations designed to protect both the quality of groundwater and the income of farmers. An economic and statistical model of a crop-pest system is used in conjunction with a groundwater loading model to derive the trade-off relationship between producer income and movement of herbicide material through the root zone. The trade-off relationship can provide the basis for formulating herbicide treatment recommendations and can also shed light on appropriate groundwater quality goals.  相似文献   

3.
ABSTRACT: An assumption of scale is inherent in any environmental monitoring exercise. The temporal or spatial scale of interest defines the statistical model which would be most appropriate for a given system and thus affects both sampling design and data analysis. Two monitoring objectives which are strongly tied to scale are the estimation of average conditions and the evaluation of trends. For both of these objectives, the time or spatial scale of interest strongly influences whether a given set of observations should be regarded as independent or serially correlated and affects the importance of serial correlation in choosing statistical methods. In particular serial correlation has a much different effect on the estimation of long-term means than it does on the estimation of specific-period means. For estimating trends, a distinction between serial correlation and trend is scale dependent. An explicit consideration of scale in monitoring system design and data analysis is, therefore, most important for producing meaningful statistical information.  相似文献   

4.
ABSTRACT: Considerable effort is expended each year in making flood peak estimates at both gaged and ungaged sites. Many methods, both simplistic and complex, have been proposed for making such estimates. The hydrologist that must make an estimate at a particular site is interested in the accuracy of the estimate. Most methods are developed using either statistical analyses or analytical optimization schemes. While publications describing these methods often include some statistical measure of goodness-of-flt, the terminology often does not provide the potential user with an answer to the question,‘How accurate is the estimate?’ That is, statistical terminology often are not used properly, which may lead to a false sense of security. The use of the correct terminology will help potential users evaluate the usefulness of a proposed method and provide a means of comparing different methods. This study provides definitions for terms often used in literature on flood peak estimation and provides an interpretation for these terms. Specific problems discussed include the use of arbitrary levels of significance in statistical tests of hypotheses, the identification of both random and systematic variation in estimates from hydrologic methods, and the difference between accuracy of model calibration and accuracy of prediction.  相似文献   

5.
The Water Erosion Prediction Project (WEPP) model has been tested for its ability to predict soil erosion, runoff, and sediment delivery over a wide range of conditions and scales for both hillslopes and watersheds. Since its release in 1995, there has been considerable interest in adding a chemical transport element to it. Total phosphorus (TP) loss at the watershed outlet was simulated as the product of TP in the soil, amount of sediment at the watershed outlet, and an enrichment ratio (ER) factor. WEPP can be coupled with a simple algorithm to simulate phosphorus transport bound to sediment at the watershed outlet. The objective of this work was to incorporate and test the ability of WEPP in estimatingTP loss with sediment at the small watershed scale. Two approaches were examined. One approach (P-EER) estimated ER according to an empirical relationship; the other approach used the ER calculated by WEPP (P-WER).The data used for model performance test were obtained from two side-by-side watersheds monitored between 1976 and 1980. The watershed sizes were 5.05 and 6.37 ha, and each was in a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation. Measured and simulated results were compared for the period April to October in each year. There was no statistical difference between the mean measured and simulated TP loss. The Nash-Sutcliffe coefficient was 0.80 and 0.78 for the P-EER and P-WER methods, respectively. It was critical for both methods that WEPP adequately represent the biggest sediment yield events because sediment is the main driver for TP loss so that the model can adequately simulate TP losses bound to sediment. The P-WER method is recommended because it does not require use of empirical parameters to estimate TP loss at the watershed outlet.  相似文献   

6.
In addition to its empirical results, this paper makes three distinct contributions to the literature on valuing fishing recreation by stated preference methods. In particular, the paper proposes a new approach to designing a choice experiment, called ‘approximate minimax design’. It employs the latest advances in optimal design theory and is much easier to compute than the ordinary minimax design. Second, the choice‐experiments are embedded in a trip frequency model, such that the changes in trip frequency can be predicted from improved fish management. Most importantly, the approach proposed in the paper provides a first step in developing dynamic fish management models, because the policies analysed may change the age‐structure of the stock. The paper also contributes with new results on anglers' valuations of angling site characteristics. They conform to traditionally obtained results but also show some unexpected results. In particular, the result does not indicate a difference in the valuation of the species caught. As expected, the application shows that the marginal value of trophy‐fish is high.  相似文献   

7.
ABSTRACT: Bayesian and non-Bayesian flood levee design methods that account for the uncertainty due to limited record length are compared using a case study. The first method, Bayesian decision theory (BDT), imbeds the uncertainty in the parameters of the yearly peak stage into a loss function. The optimum design of the flood levee, called Bayes design, corresponds to the minimum expected loss, called Bayes risk. The second method, induced safety algorithm (ISA), computes a margin of safety to be added to either an existing levee or a levee designed by classical benefit-cost analysis. The design decision is shown to fluctuate as different record lengths are considered. For short record lengths, BDT, which takes small sample bias into account, appears to yield a more conservative design than ISA. On the other hand, ISA, which is simple to implement, seems to be preferable to BDT for longer record lengths.  相似文献   

8.
The management of wild mushroom is interdisciplinary in nature, whereby the biophysical considerations have to be incorporated into the context of a wide range of social, economic and political concerns. However, to date, little documentation exists illustrating an interdisciplinary approach to management of wild mushrooms. Moreover, the empirical case studies necessary for developing applicable and practical methods are even more rare. This paper adopted an interdisciplinary approach combining participatory methods to improve the habitat management of Thelephora ganbajun, an endemic and one of the most economically valuable mushroom species in Southwest China. The paper documents an empirical case of how an interdisciplinary approach facilitated the development of a scientific basis for policy and management practice, and built the local capacity to create, adopt and sustain the new rules and techniques of mushroom management. With this integrative perspective, a sustainable management strategy was developed, which was found not only technically feasible for farmers, but also acceptable to the government from an ecological and policy-related perspective. More importantly, this approach has greatly contributed to raising the income of farmers. The paper highlights how the integration of biophysical and socioeconomic factors and different knowledge systems provided a holistic perspective to problem diagnosis and resolution, which helped to cope with conventional scientific dilemmas. Finally, it concludes that the success of this interdisciplinary approach is significant in the context of policy decentralization and reform for incorporating indigenous knowledge and local participation in forest management.  相似文献   

9.
Adaptive capacity for climate change in Canadian rural communities   总被引:5,自引:0,他引:5  
It is widely acknowledged that promoting the long-term sustainability of rural areas requires an assessment of their capacity to handle stress from a host of external and internal factors such as resource depletion, global trading agreements, service reductions and changing demographics, to name but some. The sustainability literature includes a number of approaches for conducting capacity evaluations but is sparse regarding effective methods and empirical examples. This article provides one approach for assessing community capacity and gives results from its application to a specific Canadian rural community. The authors use general capacity variables and indicators to focus on a particular stress, namely impacts from climate change, and on one type of capacity, namely the capacity to adapt (to such climatic change). A basic framework and profiling tool ('amoeba') for describing the resources underlying community adaptive capacity are offered. The researchers provide a set of indicators reflecting social, human, institutional, natural and economic resources and relate them to climate change adaptation at the community level. Although the indicators cannot be replicated exactly for other rural communities, the essentials of the framework and the profiling tool can. In fact it is hoped that the ideas and example found in this article will encourage researchers to enhance and improve on the methods and results for work on community capacity.  相似文献   

10.
Noise emanating from human activity has become a common addition to natural soundscapes and has the potential to harm wildlife and erode human enjoyment of nature. In particular, motor vehicles traveling along roads and trails produce high levels of both chronic and intermittent noise, eliciting varied responses from a wide range of animal species. Anthropogenic noise is especially conspicuous in natural areas where ambient background sound levels are low. In this article, we present an acoustic method to detect and analyze motor vehicle noise. Our approach uses inexpensive consumer products to record sound, sound analysis software to automatically detect sound events within continuous recordings and measure their acoustic properties, and statistical classification methods to categorize sound events. We describe an application of this approach to detect motor vehicle noise on paved, gravel, and natural-surface roads, and off-road vehicle trails in 36 sites distributed throughout a national forest in the Sierra Nevada, CA, USA. These low-cost, unobtrusive methods can be used by scientists and managers to detect anthropogenic noise events for many potential applications, including ecological research, transportation and recreation planning, and natural resource management.  相似文献   

11.
Abstract: Estimating stream temperatures across broad spatial extents is important for regional conservation of running waters. Although statistical models can be useful in this endeavor, little information exists to aid in the selection of a particular statistical approach. Our objective was to compare the accuracy of ordinary least‐squares multiple linear regression, generalized additive modeling, ordinary kriging, and linear mixed modeling (LMM) using July mean stream temperatures in Michigan and Wisconsin. Although LMM using low‐rank thin‐plate smoothing splines to measure the spatial autocorrelation in stream temperatures was the most accurate modeling approach; overall, there were only slight differences in prediction accuracy among the evaluated approaches. This suggests that managers and researchers can select a stream temperature modeling approach that meets their level of expertise without sacrificing substantial amounts of prediction accuracy. The most accurate models for Michigan and Wisconsin had root mean square errors of 2.0‐2.3°C, suggesting that only relatively coarse predictions can be produced from landscape‐based statistical models at regional scales. Explaining substantially more variability in stream temperatures likely will require the collection of finer‐scale hydrologic and physiographic data, which may be cost prohibitive for monitoring and assessing stream temperatures at regional scales.  相似文献   

12.
ABSTRACT: Small systematic changes in climatic records are often poorly visualized by standard time series plots because they are usually hidden by the magnitude and variability of the data values themselves. A visualization approach based on the rescaled adjusted partial sums (RAPS) which overcomes the above-stated shortcomings is presented. This visualization highlights trends, shifts, data clustering, irregular fluctuations, and periodicities in the record. Additional information on the number, magnitude, shape, frequency, and timing of fluctuations and trends can also be inferred. The visualization approach can be used for preliminary visual inspection of a time series, to gain a feel for the data, and/or to guide and focus subsequent statistical tests and analyses. It is not intended as a substitute for standard statistical analysis. Alternatively, the visualization approach can be used to display findings of a time series analysis. The capabilities and limitations of the approach are discussed and illustrated for two time series of annual rainfall values.  相似文献   

13.
This paper studies mountain hut infrastructure in the Alps as an important element of ecotourism in the Alpine region. To improve the decision-making process regarding the implementation of future infrastructure and improvement of existing infrastructure in the vulnerable natural environment of mountain ecosystems, a new decision support model has been developed. The methodology is based on qualitative multi-attribute modelling supported by the DEXi software. The integrated rule-based model is hierarchical and consists of two submodels that cover the infrastructure of the mountain huts and that of the huts’ surroundings. The final goal for the designed tool is to help minimize the ecological footprint of tourists in environmentally sensitive and undeveloped mountain areas and contribute to mountain ecotourism. The model has been tested in the case study of four mountain huts in Triglav National Park in Slovenia. Study findings provide a new empirical approach to evaluating existing mountain infrastructure and predicting improvements for the future. The assessment results are of particular interest for decision makers in protected areas, such as Alpine national parks managers and administrators. In a way, this model proposes an approach to the management assessment of mountain huts with the main aim of increasing the quality of life of mountain environment visitors as well as the satisfaction of tourists who may eventually become ecotourists.  相似文献   

14.
Abstract

It is widely acknowledged that promoting the long-term sustainability of rural areas requires an assessment of their capacity to handle stress from a host of external and internal factors such as resource depletion, global trading agreements, service reductions and changing demographics, to name but some. The sustainability literature includes a number of approaches for conducting capacity evaluations but is sparse regarding effective methods and empirical examples. This article provides one approach for assessing community capacity and gives results from its application to a specific Canadian rural community. The authors use general capacity variables and indicators to focus on a particular stress, namely impacts from climate change, and on one type of capacity, namely the capacity to adapt (to such climatic change). A basic framework and profiling tool (‘amoeba’) for describing the resources underlying community adaptive capacity are offered. The researchers provide a set of indicators reflecting social, human, institutional, natural and economic resources and relate them to climate change adaptation at the community level. Although the indicators cannot be replicated exactly for other rural communities, the essentials of the framework and the profiling tool can. In fact it is hoped that the ideas and example found in this article will encourage researchers to enhance and improve on the methods and results for work on community capacity.  相似文献   

15.
16.
近年来我国的环境问题日益引人注目,大气污染问题显得尤为突出。空气质量预测技术方法能够提前预测区域空间内的大气污染物浓度,其发展十分迅速。本文介绍了一些国内外常用的空气质量预测技术方法的原理及案例,对其结果与局限性进行归纳总结,并对其未来发展提出展望。空气质量预测技术方法分为两类:数值模拟和统计学习,数值模拟通常可以分为第一代、第二代和第三代空气质量模型,统计学习可以分为简单经验统计和机器学习。两类方法的目的都是尽可能真实、准确地实现特定时间、特定区域范围内大气污染物浓度的预测,但两类方法的原理算法差异较大。该研究系统梳理了空气质量预测技术方法演变的历程和发展的现状,展望了其发展趋势,分析了建立、健全空气质量预测技术标准规范体系的重要性,提出了相关参考建议。  相似文献   

17.
ABSTRACT: Regulatory water quality management has placed fairly extensive information expectations on routine, fixed-station monitoring without a corresponding emphasis being placed on the need to design monitoring systems to meet these expectations. To correct the situation there is increasing interest in developing more quantitative monitoring system design procedures which incorporate the statistical nature of sampling. In examining the development of such quantitative criteria, this paper describes the roles of statistics in a systematic approach to monitoring - initial design and routine reporting of results - and reviews the use of statistics in each. The paper emphasizes the need to tie the two together, via statistical design criteria, in order for the identified information expectations to be met in a statistically sound manner. However, the use of statistics in water quality monitoring is noted as currently being as much an art as it is a science.  相似文献   

18.
19.
There is a continuing debate about the proper role of analytical (positivist) science in natural resource decision making. Two diametrically opposed views are evident, arguing for and against a more extended role for scientific information. The debate takes on a different complexion if one recognizes that certain kinds of problem, referred to here as “wicked” or “trans-science” problems, may not be amenable to the analytical process. Indeed, the mistaken application of analytical methods to trans-science problems may not only be a waste of time and money but also serve to hinder policy development. Since many environmental issues are trans-science in nature, then it follows that alternatives to analytical science need to be developed. In this article, the issues involved in the debate are clarified by examining the impact of the use of analytical methods in a particular case, the spruce budworm controversy in New Brunswick. The article ends with some suggestions about a “holistic” approach to the problem.  相似文献   

20.
The importance of developing evaluative standards for judging the acceptability of impacts caused by recreation is common to all recent natural resource management frameworks. A normative model has been advanced as a useful way to conceptualize, collect, and organize empirical data representing standards for resource management issues. This article summarizes the findings from social and ecological research to illustrate the utility of the normative approach from a manager's perspective. The social data (e.g., encounter norms, proximity norms, and tolerances for launch wait times) were obtained from 13 different study sites, while the ecological data (e.g., tolerances for the amount of bare ground, size of fire rings, instream flows, and wildlife management practices) were collected at three specific sites and from one statewide survey, Findings from the social research indicated that encounter norms exist for particular types of contacts with certain types of visitors at particular places and for certain types of experiences. The recreationists reported norms for acceptable distances between individuals, encounters with others at campsites or attractions, and waiting times to run rapids. These social norm evaluation techniques were also shown to be transferable to normative evaluations of ecological impacts. The users had opinions about ecological impacts and were willing to express them. In addition, the ecological norms were of moderate to high intensity. It is argued that the usefulness of normative approaches lies in their ability to characterize group agreement about appropriate use conditions or impact levels for a particular recreation experience, thus providing the evaluative information needed to establish management standards.  相似文献   

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