Siting analyses for water quality sampling in a catchment

Pollution loads discharged from upstream development or human activities significantly degrade the water quality of a reservoir. The design of an appropriate water quality sampling network is therefore important for detecting potential pollution events and monitoring pollution trends. However, under a limited budgetary constraint, how to site an appropriate number of sampling stations is a challenging task. A previous study proposed a method applying the simulated annealing algorithm to design the sampling network based on three cost factors including the number of reaches, bank length, and subcatchment area. However, these factors are not directly related to the distribution of possible pollution. Thus, this study modified the method by considering three additional factors, i.e. total phosphorus, nitrogen, and sediment loads. The larger the possible load, the higher the probability of a pollution event may occur. The study area was the Derchi reservoir catchment in Taiwan. Pollution loads were derived from the AGNPS model with rainfall intensity estimated using the Thiessen method. Analyses for a network with various numbers of sampling sites were implemented. The results obtained based on varied cost factors were compared and discussed. With the three additional factors, the chosen sampling network is expected to properly detect pollution events and monitor pollution distribution and temporal trends.     

Human use and conservation planning in Alpine areas of Northwestern Yunnan,China

Alpine areas in northwestern Yunnan, China possess globally significant levels of biodiversity and are important locally for livelihood activities such as livestock grazing and medicinal plant collection. Because local land use has important impacts on alpine conditions and communities have significant capacity to manage alpine resources, we emphasized local collaboration during the initial stages of conservation planning. Our collaboration with local communities investigated how livelihood strategies affect the condition of alpine resources in northwestern Yunnan and how future conservation efforts can be compatible with local livelihoods. We sampled three livestock herding sites, each within a different alpine sub-region, using open-ended interviews and maximum variation sampling. According to interviewees, livestock grazing within the alpine zone currently does not appear to be negatively impacting the availability of forage. Medicinal plant collection, however, is showing unsustainable trends. Tourism is as yet a nascent industry, but is seen as having great potential by those interviewed. It is clear that with increases in population, access to regional markets, and tourism, northwestern Yunnan’s rich alpine resources will require careful management. In addition to the data collected, we found that the methodology used may be widely applicable to organizations with limited resources that wish to engage local communities during the formative stages of regional-level conservation planning.     

Analysis of composite sampling data using the principle of maximum entropy

A new tool is presented based on the principle of maximum entropy for enhanced hot spot detection based on composite sampling with no (or minimal) requirement for composite breakdown. The methodology presented here is easy to implement and facilitates the use of multiple criteria for evaluating attainment of site remediation objectives. The new methodology provides very simple decision rules that can easily be used by non-statisticians and complements the use of composites for control of residual mean concentrations.     

Estimation of the mean in line intercept sampling

Ratio estimation of the parametric mean for a characteristic measured on plants sampled by a line intercept method is presented and evaluated via simulation using different plant dispersion patterns (Poisson, regular cluster, and Poisson cluster), plant width variances, and numbers of lines. The results indicate that on average the estimates are close to the parametric mean under all three dispersion patterns. Given a fixed number of lines, variability of the estimates is similar across dispersion patterns with variability under the Poisson pattern slightly smaller than varia-bility under the cluster patterns. No variance estimates were negative under the Poisson pattern, but some estimates were negative under the cluster patterns for smaller numbers of lines. Variance estimates become closer to zero similarly for all spatial patterns as the number of lines increases. Ratio estimation of the parametric mean in line intercept sampling works better, from the viewpoint of approximate unbiasedness and variability of estimates, under the Poisson pattern with larger numbers of lines than other combinations of spatial patterns, plant width variances and numbers of lines.     

Indirect assessment of economic damages from the Prestige oil spill: consequences for liability and risk prevention

The social losses arising from the Prestige oil spill exceed the compensation granted under the IOPC (International Oil Pollution Compensation) system, with losses estimated at 15 times more than the applicable limit of compensations. This is far above the level of costs for which those responsible for hydrocarbons spills are liable. The highest market losses correspond to sectors of extraction, elaboration and commercialisation of seafood. However, damages to non-commercial natural resources could constitute an outstanding group of losses for which further primary data are needed: these losses would only be compensable under the current system by means of a refund for cleaning and restoration costs. Results show that, in Europe, the responsibility for oil spills in maritime transport is limited and unclear. The consequence of this is net social losses from recurrent oil spills and internationally accepted incentives for risky strategies in the marine transport of hydrocarbons.     

施工过程中人因差错控制效率分析

以一个钢筋砼单筋梁受弯构件正截面承载力失效概率为例,通过数值模拟发现:检查抽样率为100%的首次检查对控制人因差错非常有效,提高取样率可以有效减少和降低人因差错的发生及其影响程度,但随检查次数增加检查效率直线下降。当对各种工序进行比较细致的检查时,适当提高结构参数设计值可有效防止由较难检查出来的微小人因差错引起的结构失效。显然,质检方法、检查次数、取样率和提高结构参数设计值对人因差错控制效率的提高是十分重要的;人因差错控制效率与检查人力、物力投入成正比。上述结论对合理控制施工过程中人因差错的方案选择具有一定的现实意义。     

扩散法采集个体接触空气中氨

本文采用扩散法将空气中氨采集在磷酸———甘油浸渍的无纺布吸收层上。该法采样速率为１３７６±８４ｍｌ／ｍｉｎ，与动力采样法现场对比测定，总不确定度为±１９３％，。采样器体积小，无噪声，操作方便，适于个体接触量与室内空气污染监测     

不同采集原理的油烟采样方法研究

通过采用玻璃纤维滤筒采集、吸收液吸收和S材料滤筒采样三种不同采集原理的油烟采样方法的试验,研究出一种油烟采样新材料--SM材料,其填充后制成的S材料滤筒的油烟采集效率大于96%的采样方法.