Charging versus exclusion: Choice between recreation management tools

Overuse of recreation sites seems to justify regulation, and the principal tools for this are fee charging or physical exclusion. Both seem equally costly to administer. Both involve equal costs to consumers if recreationists visit from one origin, but if they come from different origins, costs may be greater and consumers' surplus less under either tool, depending on the shape of the demand curve. Which is the more equitable tool depends on the relative representation of rich and poor participants from near and distant origins. Potentially beneficial use of site revenues is an advantage of charging. Neither availability of substitutes nor variation in daily demand seems likely to change these results substantially, but a system of booking admissions before the trip outset might neutralize the advantages of charging. The optimal level of use varies with the regulatory tool chosen. The optimal admissions under exclusion could be fewer than or more than under charging, or may even be equal to unregulated use.     

Air Pollution Estimates in Guadalajara City

A method for estimating the impact of industrial emissions is suggested and applied to the Guadalajara City Metropolitan Area (GCMA). The method is based on solutions to the pollution transport model and its adjoint. Two equivalent direct and adjoint mean pollution concentration estimates are considered for ecologically important zones of the GCMA. The dependence of these estimates on the number, positions and emission rates of industrial plants, as well as on the wind and initial pollution distribution in the GCMA is qualitatively and quantitatively examined. It is shown that the adjoint model solutions serve as the influence functions providing valuable information on the role of each of the industrial plants in polluting different zones within the GCMA. These solutions have been calculated with a balanced and absolutely stable second-order finite-difference scheme based on the splitting method. A method for an optimal allocation of a new industrial plant is considered.     

SH波入射多个半圆形谷地浅埋圆孔的动力分析

应用辅助函数的思想，通过复变函数和多级坐标的方法给出了SH波入射条件下多个半圆形沉积谷地附近多个浅埋圆形孔洞动力分析问题的解答。求解过程中将整个求解区域划分成两部分来处理：区域Ⅰ为多个半圆形沉积谷地，区域Ⅱ为多个浅埋圆形孔洞附近带多个半圆形凹陷的半无限弹性空间。在区域Ⅰ和Ⅱ中分别构造位移解，并在二个区域的“公共边界”上实施位移、应力的连续条件，建立起求解该问题的无穷代数方程组。最后．给出了分析例题和数值结果．并对其进行了讨论。     

美国安全工程师的专业范围与职责

美国安全工程师协会（ASSE）于1911年10月14日在纽约成立,其前身是联邦伤亡事故调查委员会.ASSE在近百年的发展过程中,为美国政府制定职业安全和健康标准和法律提供了重要的依据,并且积极促进政府活动的开展,对美国职业安全卫生局的机构改革提出良好的建议.1996年ASSE机构重组,重新明确安全工程师的职责范围是保护人们的生命、财产和环境不遭破坏.本文对美国安全工程师协会的发展史、安全工程师的专业范围及职责做了简要介绍.     

关于高校教学档案的特点及其管理

教学档案是高校档案的重要组成部分,反映了高校最基本的职能活动。本文论述了高 等学校教学档案的特点、作用及其在档案管理工作中应采取的对策。     

Renewable Resources and the Idea of Nature – What Has Biotechnology Got to Do With It?

The notion that the idea of nature isnot quite the unbiased rule to designsustainable futures is obvious. But,nevertheless, questions about nature, how itfunctions and what it might aim at, is leadingthe controversial debates about bothsustainability and biotechnology. These tworesearch areas hardly have the same theorybackground. Whereas in the first concept, theidea of eternal cyclical processes is basic,the latter focuses on optimization. However,both concepts can work together, but only undera narrow range of public acceptance in Europe.The plausibility of arguments for usingbiotechnology within sustainable technologiesvaries according to the assumed part natureitself plays for reaching optimized states. Theculture related vision of nature's functionshas impact on agricultural biotechnology,dealing not only with food crops but also withnon-food plants like renewable resources thatare used for energy or fiber production. Theseplants are grown to reach sustainabledevelopment. However, there is a fundamentaldifference between regarding biofuels as``renewable' and ``regenerative,' due to thetension between the concepts of ``the natural'and ``the sustainable.' Arguments ofoptimization, efficiency, and efficacy arecritically discussed in order to take thepresent need for sustainable technologies forserious.     

COST FUNCTIONS FOR ADDITIONAL GROUND WATER DEVELOPMENT1

ABSTRACT Cost functions are determined which will allow compensation to existing users of ground water when new users require rights. These functions are dependent on the additional energy cost to existing users. The costs produced by these functions can be significant when large quantities of water are required.     

昆明市域不同生态功能类型区景观格局与生态服务价值分析

以昆明市域的8个生态功能类型区为研究对象，利用2005年土地利用变更调查数据和相关统计资料，对不同类型区的景观格局指标和生态服务价值进行计算和分析。结果表明：①整个昆明市域有较高的景观多样性和异质性，而8个类型区之间差异较大；②2005年昆明市域的生态服务价值总量为339．7124亿元，各类型区中，生态服务价值总量和单位面积生态服务价值量最高的分别是农业发展功能区和水源涵养功能区，而两者都最低的是城镇建设功能区；③农业发展功能区在景观格局特征和单位面积生态服务价值量等方面，与昆明市域的平均状况非常相似；④有些类型区在景观格局特征或生态服务价值结构上，有较大的相似性；⑤林地、水域在各类型区的地位非常突出，支配着景观的多样性稳定性，并提高了生态服务价值总量和单位面积产出量。     

对“禁止开发区”规划和管理的几点思考

通过对禁止开发区面临困境和问题的分析探讨,确定了禁止开发区的涵盖范围,并在土地管理、资源保护、财政投资和建设管护等方面提出了相关政策建议,以期为该区的有效管理提供依据。     

A Functional Land Management conceptual framework under soil drainage and land use scenarios

Agricultural soils offer multiple soil functions, which contribute to a range of ecosystem services, and the demand for the primary production function is expected to increase with a growing world population. Other key functions on agricultural land have been identified as water purification, carbon sequestration, habitat biodiversity and nutrient cycling, which all need to be considered for sustainable intensification. All soils perform all functions simultaneously, but the variation in the capacity of soils to supply these functions is reviewed in terms of defined land use types (arable, bio-energy, broadleaf forest, coniferous forest, managed grassland, other grassland and Natura 2000) and extended to include the influence of soil drainage characteristics (well, moderately/imperfect, poor and peat). This latter consideration is particularly important in the European Atlantic pedo-climatic zone; the spatial scale of this review. This review develops a conceptual framework on the multi-functional capacity of soils, termed Functional Land Management, to facilitate the effective design and assessment of agri-environmental policies. A final functional soil matrix is presented as an approach to show the consequential changes to the capacity of the five soil functions associated with land use change on soils with contrasting drainage characteristics. Where policy prioritises the enhancement of particular functions, the matrix indicates the potential trade-offs for individual functions or the overall impact on the multi-functional capacity of soil. The conceptual framework is also applied by land use area in a case study, using the Republic of Ireland as an example, to show how the principle of multi-functional land use planning can be readily implemented.