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1.
Wind resources are becoming increasingly significant due to their clean and renewable characteristics, and the integration of wind power into existing electricity systems is imminent. To maintain a stable power supply system that takes into account the stochastic nature of wind speed, accurate wind speed forecasting is pivotal. However, no single model can be applied to all cases. Recent studies show that wind speed forecasting errors are approximately 25% to 40% in Chinese wind farms. Presently, hybrid wind speed forecasting models are widely used and have been verified to perform better than conventional single forecasting models, not only in short-term wind speed forecasting but also in long-term forecasting. In this paper, a hybrid forecasting model is developed, the Similar Coefficient Sum (SCS) and Hermite Interpolation are exploited to process the original wind speed data, and the SVM model whose parameters are tuned by an artificial intelligence model is built to make forecast. The results of case studies show that the MAPE value of the hybrid model varies from 22.96% to 28.87 %, and the MAE value varies from 0.47 m/s to 1.30 m/s. Generally, Sign test, Wilcoxon’s Signed-Rank test, and Morgan--Granger--Newbold test tell us that the proposed model is different from the compared models.  相似文献   

2.
Predicting dissolved phosphorus in runoff from manured field plots   总被引:2,自引:0,他引:2  
Dissolved inorganic P transport in runoff from agricultural soils is an environmental concern. Models are used to predict P transport but rarely simulate P in runoff from surface-applied manures. Using field-plot data, we tested a previously proposed model to predict manure P in runoff. We updated the model to include more data relating water to manure ratio to manure P released during water extractions. We verified that this update can predict P release from manure to rain using published data. We tested the updated model using field-plot and soil-box data from three manure runoff studies. The model accurately predicted runoff P for boxes, but underpredicted runoff P for plots. Underpredictions were caused by runoff to rain ratios used to distribute P into runoff or infiltration. We developed P distribution fractions from manure water extraction data to replace runoff to rain ratios. Calculating P distribution fractions requires knowing rainfall rate and times that runoff begins and rain stops. Using P distribution fractions gave accurate predictions of runoff P for soil boxes and field plots. We observed relationships between measured runoff to rain ratios and both P distribution fractions and a degree of error in original predictions, calculated as (measured runoff P/predicted runoff P). Using independent field-plot data, we verified that original underpredictions of manure runoff P can be improved by calculating P distribution fractions from measured runoff to rain ratios or adjusting runoff to rain ratios based on their degree of error. Future work should test the model at field or watershed scales and at longer time scales.  相似文献   

3.
基于Meta分析的中国水资源价值移位研究   总被引:1,自引:1,他引:0       下载免费PDF全文
Meta分析价值移位方法是国际上资源价值评价领域关注的热点,国内相关研究较少。水作为重要的自然资源,研究其价值是解决我国水资源问题的关键途径。本文搜集我国水资源价值评估实证研究结果,建立效益移位基础数据库,应用基于Meta分析的函数效益移位方法,对我国水资源价值移位做实证研究,探讨效益移位法在我国水资源价值评估领域的可应用性及发展前景。结果表明:①水资源所在地、人口密度、水质、供水成本和利润以及对最大水费承受程度的差异会影响地区水资源价值变化;②模型平均移位误差在可接受范围内,可用于快速评估地区水资源价值;③省级层面水资源价值呈现出沿海高于内陆,华北、华东和西南高于其他地区的空间分异 规律。  相似文献   

4.
We intend to estimate the value of ecosystem services in the U.S. State of New Jersey using spatially explicit benefit transfer. The aggregated net rent, a conservative underestimate for the total economic value of the state’s natural environment, ranged from 11.6 to11.6 to 19.6 billion/year, conditional on how inclusive we were in selecting the primary studies used to calculate the central tendency values to transfer. In addition to calculating the range, mean, and standard deviation for each of 12 ecosystem services for 11 Land Use/Land Cover (LULC) types, we also conduct a gap analysis of how well ecosystem service values are represented in the literature. We then map these values by assuming a mean value for each LULC and apply this to spatial data. As to sensitivity analysis, we calculate the net present value of New Jersey’s natural environment utilizing three different methods of discounting. These research results provide a useful, albeit imperfect, basis for assessing the value of ecosystem services and natural capital, and their comparison with the value of conventional human and built capitals.  相似文献   

5.
Endogeneity bias arises in contingent valuation studies when the error term in the willingness to pay (WTP) equation is correlated with explanatory variables because observable and unobservable characteristics of the respondents affect both their WTP and the value of those variables. We correct for the endogeneity of variables that capture previous experience with the resource valued, humpback whales, and with the geographic area of study. We consider several endogenous behavioral variables. Therefore, we apply a multivariate Probit approach to jointly model them with WTP. In this case, correcting for endogeneity increases econometric efficiency and substantially corrects the bias affecting the estimated coefficients of the experience variables, by isolating the decreasing effect on option value caused by having already experienced the resource. Stark differences are unveiled between the marginal effects on WTP of previous experience of the resource in an alternative location versus experience in the location studied, Newfoundland and Labrador (Canada).  相似文献   

6.
The rewilding of landscapes is one of the most important and intensively discussed landscape changes occurring in Switzerland, as the need for agricultural and forest land is decreasing. To ensure that decisions concerning future landscape management will be supported by the public, it is crucial to take public opinion into account. Hence the present study aims to assess the public attitudes towards nature and "rewilding" processes. In order to analyze these attitudes, we sent a standardized questionnaire to 4000 randomly selected households throughout Switzerland. A cluster analysis led to a typology with four different types of human-nature relationship ("nature lovers", "nature sympathizers", "nature-connected users" and "nature controllers") that each characterize a particular attitude towards nature. These human-nature relationship types differ in their attitudes towards rewilding as well, allowing a rough classification of the sample into wilderness opponents (51.1%) and wilderness proponents (49.9%). However both groups agree with regard to their opinion concerning the rules and regulations that should apply in future wilderness areas. The parallels of the human-nature relationship typology of this survey with other typologies, and the implications for further research are discussed. We can conclude that, due to the differences concerning the attitudes towards wilderness between the human-nature relationship types, between the rural and urban dwellers, and between the language regions, a uniform strategy for the designation and management of wilderness areas in Switzerland is not possible. We recommend that, when managing landscape change, all stakeholders are included in a participatory process and we advise a thorough assessment of the attitudes of the involved persons towards nature and rewilding at the start of such processes. Such an assessment would facilitate the identification of well-defined target groups allowing specific interventions and management actions customized to the needs and characteristics of each of these groups. In addition we see the commonalities between wilderness opponents and wilderness proponents concerning the rules in wilderness areas as an ideal starting point for a successful participatory process.  相似文献   

7.
粮食估产的“通道-概率”理论:把属于最近通道的历年来的产量划分为5个气候年型通道,即丰产年、偏丰年、平产年、偏欠年、欠产年;计算产量出现在5个气候年型中的频率作为概率使用,估产年的初始估产值等于预测年各通道内平均产量与概率之积的和;估产值等于初始估产值与气候年型修正参数之积,专家根据当年气候条件和作物长势实时确定修正参数。预报单元为全国、省和县。应用结果表明:国家尺度上不需要修正,省和县级尺度需要气候年型参数修正;预测误差在3%以内;所述估产理论严谨、方法简单,参数少,参数来自原始数据本身和专家经验,易于推广使用。  相似文献   

8.
The interest in improved environmental sustainability of agriculture via biodiversity provides an opportunity for placed-based research on the conceptualization and articulation of ecosystem services. Yet, few studies have explored how farmers conceptualize the relationship between their farm and nature and by extension ecosystem services. Examining how farmers in the Southern Piedmont of South Carolina discuss and explain the role of nature on their farm, we create a detail-rich picture of how they perceive ecosystem services and their contributions to the agroeconomy. Using 34 semi-structured interviews, we developed a detail-rich qualitative portrait of these farmers’ conceptualizations of ecosystem services. Farmers’ conceptualization of four ecosystem services: provisioning, supporting, regulating, and cultural are discussed, as well as articulation of disservices. Results of interviews show that most interviewees expressed a basic understanding of the relationship between nature and agriculture and many articulated benefits provided by nature to their farm. Farmers referred indirectly to most services, though they did not attribute services to biodiversity or ecological function. While farmers have a general understanding and appreciation of nature, they lack knowledge on specific ways biodiversity benefits their farm. This lack of knowledge may ultimately limit farmer decision-making and land management to utilize ecosystem services for environmental and economic benefits. These results suggest that additional communication with farmers about ecosystem services is needed as our understanding of these benefits increases. This change may require collaboration between conservation biology professionals and extension and agriculture professionals to extended successful biomass provisioning services to other ecosystem services.  相似文献   

9.
Due to its nature, agricultural land use depends on local site characteristics such as production potential, costs and external effects. To assess the relevance of the modifying areal unit problem (MAUP), we investigated as to how a change in the data resolution regarding both soil and land use data influences the results obtained for different land use indicators. For the assessment we use the example of the greenhouse gas (GHG) emissions from agriculturally used organic soils (mainly fens and bogs). Although less than 5 % of the German agricultural area in use is located on organic soils, the drainage of these areas to enable their agricultural utilization causes roughly 37 % of the GHG emissions of the German agricultural sector. The abandonment of the cultivation and rewetting of organic soils would be an effective policy to reduce national GHG emissions. To assess the abatement costs, it is essential to know which commodities, and at what quantities, are actually produced on this land. Furthermore, in order to limit windfall profits, information on the differences of the profitability among farms are needed. However, high-resolution data regarding land use and soil characteristics are often not available, and their generation is costly or the access is strictly limited because of legal constraints. Therefore, in this paper, we analyse how indicators for land use on organic soils respond to changes in the spatial aggregation of the data. In Germany, organic soils are predominantly used for forage cropping. Marked differences between the various regions of Germany are apparent with respect to the dynamics and the intensity of land use. Data resolution mainly impairs the derived extent of agriculturally used peatland and the observed intensity gradient, while its impact on the average value for the investigated set of land-use indicators is generally minor.  相似文献   

10.
Mayer and Frantz (2004) proposed that their connectedness to nature scale (CNS) provides a measure of people's emotional connection to nature. After reanalyzing data from their article, collecting and analyzing our own data, and conducting a content analysis of CNS scale items, we conclude that the CNS does not measure an emotional connection to nature. Although results from our Study 1 and Study 2 support Mayer and Frantz's conclusion that the CNS measures one predominant factor, we suggest that factor measures cognitive beliefs and not emotional connections. Results from our Studies 3 and 4 suggest that the self-referential, less negatively toned wording of CNS items may account for differences in correlations, between the CNS and environmentalism (a measure of environmental identity) and between the New Ecological Paradigm Scale (a measure of environmental beliefs) and environmentalism, reported by Mayer and Frantz. In Study 5, we suggest that correlation differences reported by Mayer and Frantz may also be attributable to method variance, as opposed to content differences between the CNS and the New Ecological Paradigm scale. We provide recommendations for revising the CNS to focus on beliefs about their connection to nature.  相似文献   

11.
The simplest type of model describing animal habitats is a “cover-type model,” in which a species is assumed to be present in certain vegetation types and absent in others. Ecologists and managers use these models to predict animal distributions for gap analysis and conservation planning. Critics, however, have suggested that the models are overly simplistic and inaccurate. We reviewed the use of cover-type models including assessing their error rates, diagnosing the problems with these models, and determining how they should best be used by managers. To determine models’ accuracy rates, we conducted a meta-analysis of 35 studies in which cover-type models were tested against data on animal occurrences. Models had a mean accuracy rate of 0.71 ± 0.18 (SD). Rates of commission error averaged 0.20 ± 0.16, and omission errors averaged 0.09 ± 0.11. A review of the effects of errors in conservation planning suggests that the observed error rates were high enough to call into question any management decisions based on these models. Reasons for the high error rates of cover-type models include the fallibility of expert opinion, the fact that the models oversimplify how animals actually use habitats, and the dynamic nature of animal populations. Given the high rate of errors in cover-type models, any conclusions based on them should be taken with extreme caution. We suggest that these models are best used as coarse filters to identify locations for further study in the field.  相似文献   

12.
Although the notion of natural behavior occurs in many policy-making and legal documents on animal welfare, no consensus has been reached concerning its definition. This paper argues that one reason why the notion resists unanimously accepted definition is that natural behavior is not properly a biological concept, although it aspires to be one, but rather a philosophical tendency to perceive animal behavior in accordance with certain dichotomies between nature and culture, animal and human, original orders and invented artifacts. The paper scrutinizes the philosophy of natural behavior as it developed in the organic movement in response to a perceived contrast between industrialized and traditional agriculture. There are two reasons for focusing on the organic movement: (i) the emphasis on “the natural” is most accentuated there and has a long history, (ii) everyday life on organic farms presupposes human/animal interplay, which conflicts with the philosophical tendency to separate nature from culture. This mismatch between theory and practice helps us see why, and how, the philosophy of natural behavior needs to be reconsidered. The paper proposes that we understand farms as local human/animal cultures, and asks what we can mean my natural behavior in such contexts. Since domestic animals adapt to agricultural environments via interaction with caretakers, such interplay is analyzed as “hub” in these animals’ natural behavior.  相似文献   

13.
14.
Despite a growing body of literature on public views on biodiversity and nature, our understanding of public attitudes towards animal and plant species is still rudimentary. This study investigates mental representations, constituted by beliefs, of three types of species (a large mammal, a spider and a non-native plant), and explores their links with cultural factors such as value orientations and cultural capital, in order to better understand attitudes towards these species.We conducted a survey in eight sites across Europe (n = 2378) and found strong relationships between beliefs about species, in particular with regard to their harmlessness, value and previous population change, and the desirability of an increase in this species. Other beliefs, such as perceived nativeness, were less influential. We discuss how respondents combined beliefs to mental representations of species, and show how representations are related to species-independent factors that tap respondents’ cultural context, such as socially shared value orientations and education.  相似文献   

15.
In the 1960s, western societies discovered that unlimited technological progress has a very high price that the environment pays. This was also the beginning of the discussions on the role of ethics in the protection of the environment and the moral aspects of nature exploitation. Even though the state of nature was not better in Poland, it took Polish philosophers a few decades to recognize the moral problem and to address it. The prevailing communistic propaganda of progress had blurred the perception of Polish people and they are unable to notice the environmental problem. Thus, only in the 1990s, after the fall of communism, Polish philosophers noticed that our approach to nature can have a moral aspect and we are exhausting the resources of the Earth. Since then, Environmental Ethics in Poland has been developed. Polish Environmental Ethics (PEE) is an interesting blend of inspiration from internationally recognized thinkers as well as original approaches to the ecological problem. The first wave of PEE addresses problems discussed abroad, namely the range of ethics (whom do we include into ethical consideration?) and the problem of values, analyzing them in the context of Polish culture and philosophical traditions. It also proposed original approaches developed by Henryk Skolimowski as well as approaches inspired by the problems considered from the perspective of Catholic theology. The article will give an insight into PEE and will present how these applied ethics have been received and cultivated in Poland in the so called first wave. It will also highlight the problems of the second wave of PEE.  相似文献   

16.
Not much is known about lay public perceptions of non-native species and their underlying values. Public awareness and engagement, however, are important aspects in invasive species management. In this study, we examined the relations between the lay public’s visions of nature, their knowledge about non-native species, and their perceptions of non-native species and invasive species management with a survey administered in the Netherlands. Within this framework, we identified three measures for perception of non-native species: perceived risk, control and engagement. In general, respondents scored moderate values for perceived risk and personal engagement. However, in case of potential ecological or human health risks, control measures were supported. Respondents’ images of the human–nature relationship proved to be relevant in engagement in problems caused by invasive species and in recognizing the need for control, while images of nature appeared to be most important in perceiving risks to the environment. We also found that eradication of non-native species was predominantly opposed for species with a high cuddliness factor such as mammals and bird species. We conclude that lay public perceptions of non-native species have to be put in a wider context of visions of nature, and we discuss the implications for public support for invasive species management.  相似文献   

17.
We examined whether value differences between various recreation interest/activity groups are created and sustained by the textual information presented to their readers in magazines. Using a two-stage qualitative approach, our research sought to explore the exact nature of the dialogue in the magazines. We sought detailed, intimate information on a selected number of magazines to assess how the popular press socially constructs knowledge about recreation groups, and we sought to better understand how various recreation group members assign meaning to their activities and interpret the interests of other groups. Findings revealed limited negativity of activity users towards one another; most of the conflict found in the text of the articles in recreational magazines was characterized as macrodispositional. Accordingly, in the articles most of the antipathy was directed towards government because of stricter regulation of activity or towards commercial consumers whose exploitation of resources is perceived to threaten groups' activities. Moreover, such conflict crosscuts various groups whose issues and concerns are often similar. Since environmental battles are no longer any one group's issue, many have coalesced and engaged in conflict with lawmakers and commercial consumers. It is clear that the recreational magazines do play a role in shaping readers' attitudes.  相似文献   

18.
The main aim of this article is to demonstrate a method of complex landscape analysis in order to estimate the landscape suitability for the construction of surface-flow wetlands (SFW) for wastewater treatment. This is a multilevel suitability analysis from a more general regional (landscape) assessment based on a map of landscape types (1:100,000) toward a detailed analysis based on aerial orthophotos and detailed soil maps (1:10,000). The assessment scheme consists of landscape classification according to the physical-chemical properties of landscape factors (soil conditions, landforms, hydrogeology, expert decisions concerning landscape values, and suitability analysis). The partial suitability values of SFWs are derived by summarizing expert values for landscape factors (each ranging from -1 to +1). By multiplying the summarized partial suitability values with nature protection values (ranging from 0 to 1), we obtain the final suitability value for each landscape type. Any kind of nature protection area has been considered nonsuitable and excluded at regional-level analysis. The results of the regional analysis demonstrate that suitability is distributed relatively equally over the study area. The high suitability potential (classified as "very suitable") is relatively evenly distributed in lowland regions throughout the country. The share of "very suitable" and "suitable" areas in different counties varies from 5 to 23% and 7 to 49%, respectively. The detailed analysis based on aerial orthophotos showed that areas suitable for SFWs can also be found within the areas determined to be unsuitable based on the less detailed map of landscape types, whereas differences are much greater between settlements chosen for the detailed suitability analysis.  相似文献   

19.
In this communication, a new design of solar-energy-based water distillation cum drying unit with parabolic reflector has been designed, fabricated, and tested. Bitter gourd and potato slices are chosen as a drying commodity. Thermal performance of the developed system has been evaluated based on the experimental results and using linear regression analysis. Heat transfer coefficients (convective, evaporative, and radiative) for solar distillation system have been observed to be 2.48–4.09, 13.25–52.38, and 8.75–9.66 W/m2°C, respectively. Overall thermal efficiency and exergy efficiency for the distillation system has been found to be 18.77% and 1.2%, respectively. The convective heat transfer coefficient for potato slices are observed higher for initial hours and decreases as the day progresses. The average convective heat transfer coefficients for bitter gourd and potato slices have been observed as 2.18 and 5.04 W/m2°C, respectively. Experimental error in terms of percent uncertainty for bitter gourd and potato slices are found to be 42.93% and 37.06%, respectively. The present design of solar distillation and drying in a single unit could be beneficial for the development of remote, arid, and rural areas.  相似文献   

20.
喀拉峻草原被联合国专家誉为“无与伦比的世界最美草原”,是世界自然遗产《中国新疆天山》的组成部分。该地有着完整的垂直自然景观带,是天山中部北坡典型代表地段之一,是原始西天山五花草甸草原和野生珍稀动植物的基因库,建立喀拉峻自然保护区有深远的科学及生态经济价值。  相似文献   

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