Effects of Weighting Schemes on the Identification of Wildlife Corridors Generated with Least‐Cost Methods

The importance of movement corridors for maintaining connectivity within metapopulations of wild animals is a cornerstone of conservation. One common approach for determining corridor locations is least‐cost corridor (LCC) modeling, which uses algorithms within a geographic information system to search for routes with the lowest cumulative resistance between target locations on a landscape. However, the presentation of multiple LCCs that connect multiple locations generally assumes all corridors contribute equally to connectivity, regardless of the likelihood that animals will use them. Thus, LCCs may overemphasize seldom‐used longer routes and underemphasize more frequently used shorter routes. We hypothesize that, depending on conservation objectives and available biological information, weighting individual corridors on the basis of species‐specific movement, dispersal, or gene flow data may better identify effective corridors. We tested whether locations of key connectivity areas, defined as the highest 75th and 90th percentile cumulative weighted value of approximately 155,000 corridors, shift under different weighting scenarios. In addition, we quantified the amount and location of private land that intersect key connectivity areas under each weighting scheme. Some areas that appeared well connected when analyzed with unweighted corridors exhibited much less connectivity compared with weighting schemes that discount corridors with large effective distances. Furthermore, the amount and location of key connectivity areas that intersected private land varied among weighting schemes. We believe biological assumptions and conservation objectives should be explicitly incorporated to weight corridors when assessing landscape connectivity. These results are highly relevant to conservation planning because on the basis of recent interest by government agencies and nongovernmental organizations in maintaining and enhancing wildlife corridors, connectivity will likely be an important criterion for prioritization of land purchases and swaps. Efectos de los Esquemas de Ponderación sobre la Identificación de Corredores para Vida Silvestre Generados con Métodos Menos Costosos     

经济发展与防灾成本分析

通过一个数量模型探讨了防灾投资、生产投资、灾害发生率与经济发展之间的关系,提出了在经济发展过程中加大防灾力度的理论依据。最后运用浙江省10年来的数据,说明了现阶段加大防灾投资的必要性。     

Agricultural work related injury and Ill-health and the economic cost

This paper contains a literature review of the occupational injuries and ill-health in agriculture world-wide and a survey of the attempts that have been made to estimate the resulting economic and social costs. Agricultural workers suffer a wide variety of disorders as a result of their occupation. These range from minor (cuts, bruises) to more severe (deep wounds, fractures), permanent (amputation, spinal cord injury) and fatal injury. Ill-health as a result of contact with animals, micro-organisms, plant material dusts or chemicals are associated with certain types of agriculture. There is an underlying but unquantified incidence of pain, stress and injury as a result of ergonomic problems due to poor working procedures and conditions. Statistics from many countries or regions show that agriculture consistently has one of the highest accident and injury rates of the industrial sectors. There are many causes for the work related injury and ill-health in agricultural workers. In developed countries, tractors and other machinery cause a significant proportion of the accidents and are a major cause of occupational deaths. In less developed countries, accidents due to hand tools such as hoes, sickles and cutting instruments are most prevalent. Animals are a significant cause of injury and ill-health in many countries. Debilitating allergic reactions in the respiratory tract or the skin are caused by exposures to organic dusts, or by contact with allergenic plants in the field respectively. Where comparative data are available, occupational pesticide poisoning in agriculture is a small proportion (< 1–4%) of the total work related disorders. Because of the wide variety of occupational risks to agricultural workers, it is emphasised that if one type of agricultural practice is replaced by another then the risks from the alternative procedure need to be considered. If, for example, agrochemical pest control practices are replaced by methods involving the increased use of machinery, draught animals or manual operations, then an assessment of the resulting risks should be taken into account. Some of the economic costs of occupational injury and ill-health in agriculture can be quantified directly, such as medical costs, the cost of rehabilitation and loss of earnings. Other costs are more difficult to estimate such as loss of opportunity and income foregone for permanent and fatal injury and for the effect on a victim’s family. The estimation of the overall economic costs to farming communities and national agriculture requires further development. When one agricultural practice is replaced wholly or partly by another, for example agrochemical pest control by alternative control methods, then it is necessary to take into account the occupational health costs of the alternative procedure for realistic comparative assessment. There are a number of issues which require continued or increased attention by the relevant national and international authorities and by the agricultural industry. These include the improved collection and collation of occupational health statistics, a better understanding of the extent of ergonomic problems in agriculture, more realistic assessments of the cost of occupational injury and ill-health and the continued need to reduce occupational health disorders by appropriate training and education in agricultural practices and the use of agricultural equipment.     

流域水质资源有偿使用机制的思考

阐述了水质资源的基本概念和水质资源计价原则及定价方法，介绍了恢复成本法作为水质资本定价方法和确定水质资本核算函数和曲线的步骤。〖JP2〗然后从有偿使用与生态补偿的概念、使用权和所有权以及支付方式3个方面对二者进行比较，指出有偿使用体制可实现水质资源使用权与国家所有权分离，从而可构成市场主体的财产权。基于以上概念和方法，从分析东江水源区的优质水保护与东江供水的关系入手，指出实行水质资源有偿使用的迫切性和重要性，从实现社会公平和完善市场机制两方面分析有偿使用的必要性，并提出了有偿使用机制的若干建议。     

无费低费方案的实施是清洁生产成功的关键

叙述了我国目前清洁生产审核试点阶段出现的问题，认为根源在于未能有效地执行清洁生产审核中提出的无费低费方案，并提出了解决这些问题的方法。     

Development and valuation of adaptation pathways for storm water management infrastructure

Policymakers today are faced with a difficult task of planning for large scale infrastructure that can cater to the climatic and socio-economic changes that the future will bring. To address the deeply uncertain nature resulting from long-term changes, it is becoming necessary to develop strategies that support flexibility and react more strategically than traditional planning approaches. This paper applies the concept of adaptation tipping points and adaptation pathways to a case study in Singapore for the planning of long-term urban drainage infrastructure. Using conventional grey and sustainable green solutions in isolation and in combination, adaptation pathway maps are developed and compared across outlined climatic and landuse scenarios. To understand and justify if the imparted flexibility is worth its cost, economic assessments are performed. This is a valuable extension of the existing framework, helps to identify the preferred configuration of land use and sub-select adaptation actions that should be implemented at the current time frame. The main finding of this study is that the adaptation pathways map for the sustainable grey landuse scenario economically outperforms those of the other outlined land uses. This provides a valuable insight for policy makers, as it implies that if carefully planned development is undertaken, the requirements of storm water management can be met in a sustainable manner, while simultaneously freeing up land for other purposes. This is especially important in the context of highly dense urban areas such as Singapore, where land is a scare resource.     

Determining distribution coefficients for low cost adsorbents

As with other construction materials, coal fly ash contains trace metals that can leach into the natural environment. As part of a broader effort to encourage appropriate coal combustion product use in infrastructure applications (e.g., road construction, stabilization, and structural fill), this study evaluated traditional and low‐cost adsorbent alternatives for their capacity to attenuate trace metals. Batch sorption tests were used as a preliminary screen for a wide variety of low cost (e.g., steel byproducts, rubber dust, and compost) and innovative materials (e.g., kudzu, biofilm, and pond weed) as well as conventional materials (activated carbon, alumina, and zeolites). The removal rates were demonstrated in this study by observing the calculated distribution coefficient (K_d) which were determined using a program called MATLAB. Limestone and steel byproducts were found to be particularly effective with large K_d values of 15,740, 1,520, and 540 L kg^?1 for cadmium, chromium, and selenium and, for ladle refractory and mill scale, K_d values of 3,910, 670, and 1,760 L kg^?1 were observed. Among the three metals tested for this study, it was observed that most low cost and innovative materials removed cadmium quite efficiently; however, the removal of selenium and chromium depended on the substrate and prevailing pH. In general, these results suggest that alternative materials may have relevance in niche applications where leaching is a concern that can be addressed through enhanced attenuation capacity via blending or layering of adsorbents.     

施工承包企业安全成本及其核算的研究

依据施工承包企业安全管理的目标、特点和程序,提出安全成本的概念和构成以及保证性安全成本对损失性安全成本的直接影响.同时,借助施工安全成本与安全度的关系、提高安全技术工作的经济合理性、加速构建施工承包企业安全成本核算制度,优化施工承包企业的安全管理工作,并为提高企业经济效益及社会经济运行的安全度奠定基础.     

Pilot study for the treatment of sodium and fluoride-contaminated groundwater by using high-pressure membrane systems

High-pressure membrane process is one of the cost-effective technologies for the treatment of groundwater containing excessive dissolved solids. This paper reports a pilot study in treating a typical groundwater in Huaibei Plain containing excessive sodium, sulfate and fluoride ions. Three membrane systems were set up and two brands of reverse osmosis (RO), four low-pressure RO (LPRO) and one tight nanofiltration (NF) membranes were tested under this pilot study. An apparent recovery rate at about 75% was adopted. Cartridge filtration, in combination with dosing antiscalent, was not sufficient to reduce the fouling potential of the raw water. All RO and LPRO systems (except for the two severely affected by membrane fouling) demonstrated similar rejection ratios of the conductivity (~98.5%), sodium (~98.5%) and fluoride (~99%). Membrane fouling substantially reduced the rejection performance of the fouled membranes. The tight NF membrane also had a good rejection on conductivity (95%), sodium (94%) and fluoride (95%). All membranes rejected sulfate ion almost completely (more than 99%). The electricity consumptions for the RO, LPRO and NF systems were 1.74, 1.10 and 0.72 kWh?m^-3 treated water, respectively. The estimated treatment costs by using typical RO, LPRO and tight NF membrane systems were 1.21, 0.98 and 0.96 CNY?m^-3 finished water, respectively. A treatment process consisting of either LPRO or tight NF facilities following multi-media filtration was suggested.