Decision Tree Algorithm for Detection of Spatial Processes in Landscape Transformation

The conversion of landscapes by human activities results in widespread changes in landscape spatial structure. Regardless of the type of land conversion, there appears to be a limited number of common spatial configurations that result from such land transformation processes. Some of these configurations are considered optimal or more desirable than others. Based on pattern geometry, we define ten processes responsible for pattern change: aggregation, attrition, creation, deformation, dissection, enlargement, fragmentation, perforation, shift, and shrinkage. A novelty in this contribution is the inclusion of transformation processes causing expansion of the land cover of interest. Consequently, we propose a decision tree algorithm that enables detection of these processes, based on three parameters that have to be determined before and after the transformation of the landscape: area, perimeter length, and number of patches of the focal landscape class. As an example, the decision tree algorithm is applied to determine the transformation processes of three divergent land cover change scenarios: deciduous woodland degradation in Cadiz Township (Wisconsin, USA) 1831–1950, canopy gap formation in a terra firme rain forest at the Tiputini Biodiversity Station (Amazonian Ecuador) 1997–1998, and forest regrowth in Petersham Township (Massachusetts, USA) 1830–1985. The examples signal the importance of the temporal resolution of the data, since long-term pattern conversions can be subdivided in stadia in which particular pattern components are altered by specific transformation processes.     

从行为科学角度浅论家具生产企业安全管理

家具生产企业的安全状况如何,直接影响企业的经济效益,影响着生产员工的情绪稳定.本文旨在运用行为科学理论,剖析家具生产企业事故发生的原因,并提出了避免出现安全事故的相应措施,促进家具企业的健康发展.     

FIELD-LABORATORY DETERMINED AVOIDANCES OF THE SPOTFIN SHINER AND THE BLUNTNOSE MINNOW TO CHLORINATED DISCHARGES1

ABSTRACT: The responses of the spotfin shiner (Notropis spilopterus) and bluntnose minnow (Pimephales notatus) to intermittent chlorine discharges from a fossil fuel power plant in the New River were investigated by seine collections in the chlorinated discharge channel, and chlorine avoidances were obtained in a field laboratory at the power plant in Glen Lyn, Virginia. No fish were captured by seine during chlorination periods when the total chlorine (TCR) and free chlorine (FCR) residuals were, respectively, 0.46 and 0.27 mg/1 or higher at river water temperatures of 12 C or less. For collections made between eight-hour chlorination periods, the number of fish was reduced by approximately 50% at 0.20 and 0.06 mg/1 TCR and FCR, respectively. Significant (0.05 level) laboratory avoidances occurred at 0.10 to 0.20 mg/1 TCR (0.03 to 0.14 mg/1 FCR) for both species when exposed to increasing TCR concentrations of 0.10, 0.20, 0.30 and 0.40 mg/1. Responses varied with acclimation temperature (6, 12, 18 and 24 C) with no consisteent trends between species. When exposed to a constant TCR concentration during any one test (0.14, 0.18 and 0.26 mg/1 for the spotfin shiner, and 0.11 and 0.17 mg/1 for the bluntnose minnow), significant avoidances were observed at 0.26 and 0.17 mg/1 for each species, respectively. In all laboratory trials, occurrence or residence times decreased with increasing chlorine concentration, with residence times as high as 64.7% at 0.10 mg/1 TCR and as low as 8.3% at 0.40 mg/1 being observed.     

城市地下空间管道施工坍塌事故行为原因研究

为了进一步了解城市地下空间管道施工坍塌事故发生的原因,笔者运用行为安全"2-4"模型事故致因分析方法分析了27起典型的管道施工坍塌事故,分析得出17类共109个不安全动作和6类共34个不安全物态,不安全动作中发生率较高的是不按要求对基坑放坡和加固、未对作业人员安全教育培训或者培训不到位以及施工前未进行风险识别或者识别不到位,并对这3方面不安全动作进行进一步分析;不安全物态中发生率较高的是未加支撑的基坑侧壁、存在淤泥和松软土质结构的开挖层。得出安全知识不足7类共58项,安全意识的淡薄,对于生产主管主要体现在雇佣临时工,施工现场作业人员则体现在不注意环境周围存在的安全隐患;得出安全管理体系的欠缺9类共88项,因安全生产规章制度缺乏或制度不合格导致安全管理体系欠缺占比最大,因无安全技术交底或技术交底不到位导致安全管理体系的欠缺居于第二位,施工前未进行风险识别或者识别不到位在27起事故中也出现12次,也是安全管理工作中不可忽视的因素。     

Examining motor vehicle crash involvement and readiness to change on drinking and driving behaviors among injured emergency department patients

Objective: To measure the effect of motor vehicle crash (MVC) involvement and readiness to change drinking and driving behaviors on subsequent driving and drinking behaviors among injured emergency department (ED) patients who use alcohol at harmful levels.

Methods: This was a secondary analysis of a randomized controlled trial of injured ED patients who screened positive for harmful alcohol use, who at recruitment reported driving in the past 12 months and received at least one of the intended intervention sessions (brief behavioral intervention versus attention placebo control; N = 407). Outcome variables were as follows: (1) change in 6 impaired driving behaviors and (2) report of MVCs and traffic violations in the 12 months following recruitment; predictor variables were as follows: (1) treatment assignment, (2) MVC involvement at recruitment, and (3) baseline readiness to change alcohol use and drinking and driving.

Results: Modeling of change in the 6 impaired driving variables indicated that neither the recruitment visits being MVC related nor baseline readiness to change alcohol use and drinking and driving behaviors predicted greater changes in impaired driving over time. Baseline reports of past moving traffic violations and the ED visit being MVC related predicted a greater likelihood of each behavior at 12 months following study recruitment.

Conclusions: This study and others have demonstrated that ED patients with harmful alcohol use are willing to engage in behavioral interventions directed at changing risky behaviors. However, this study did not demonstrate that patients considered having the potential to be more engaged with the intervention because their ED visit was MVC related and/or they had expressed intent to change their risky alcohol use and drinking and driving behaviors were more likely to change these risky behaviors.     

近35a来广州城市绿色空间及破碎化时空分异

伴随城市化进程的加快,绿色空间作为城市基础性要素之一,其稀缺性和作用日益凸显。论文以1979—2014年为研究时段,基于覆盖广州市域的7个时相Landsat影像获取城市绿色空间的信息,首先分析城市绿色空间数量变化与强度,再从研究区整体、境内各行政区单元和自中心城区向外人为划定的梯度景观等不同尺度对绿色空间破碎化的时空分异进行量化研究。得到以下主要结论:城市空间自中心向外扩展蔓延;城市绿色空间总量在研究始末变化不大,但随不同的时段呈起伏变化,其中1979—1990、2000—2005年间增幅较大,分别为2.3%和5.3%,1990—2000年则降幅较大,为-2.7%。绿色空间破碎化的时空差异明显,研究区绿色空间破碎化波动变化,呈减少(1990—2000年)—增加(2000—2005年)—减少(2005—2014年)之态势;而行政区的尺度上,与中心区毗邻的番禺、白云和花都区的阶段性特点突出,破碎化程度较大;在自中心区向外围的圈层梯度景观,也同样呈现阶段性变化特点。表明经济发展与对绿色空间的重视未尽同步,未来城市的可持续发展必须足够重视和优化绿色空间。     

基于斑马鱼行为变化的水体突发汞污染生物预警技术研究

针对突发水污染事件难以准确预警的现状,通过模拟水体突发汞污染事件,开展了以生物鱼行为变化为基础的水质生物预警技术研究。以正常水体中斑马鱼的行为变化为基础,采用高速摄像跟踪技术,解析了突发汞污染(0.1mg/L)水体中斑马鱼游动行为(游动速度、高度、转弯次数、加速度)和通讯行为(平均距离、分散度)等行为指标的变化,结果表明:综合评价指标水质健康指数6h内无法预警,以游动高度作为水体突发汞污染事件的监测预警指标,可将预警时间缩短至3h。     

考虑行为特征的人群疏散模拟研究*

为研究聚集活动中的行人在移动过程中所表现出的行为特征对人群整体移动过程的影响,通过实验观察与计算机仿真模拟的方法对人员移动进行研究。通过对实验视频的观察分析,在CTM模型基础上建立考虑人员跟随行为与保持距离行为特性的移动模型,并在简单无障碍和复杂多障碍的场景进行仿真实验。结果表明:模型能有效地描述行人的运动特征,而且拥挤程度和行人间排斥作用越大时行人移动越慢,整个疏散过程花费时间越长;障碍物的存在会影响人群在出口处的“成拱现象”,对理解人员的运动规律和防止拥挤踩踏事故具有一定理论和现实意义。     

Long-Term Avifaunal Impoverishment in an Isolated Tropical Woodlot

Abstract:  Long-term (>50 years) extinction patterns and processes in isolated tropical forest patches are poorly understood. Considering that forest fragments are rapidly becoming the common feature of most tropical landscapes, data on the long-term conservation value of such fragments are urgently needed. We report on avifaunal turnover in a tropical woodlot (Bogor Botanical Gardens; 86 ha; 54% native and 46% introduced plants; mean 83,649 visitors/month) that has been surveyed several times before and after its isolation in 1936. By 2004 the original avifaunal richness of this woodlot declined by 59% (97 to 40 species) and its forest-dependent avifauna declined by 60% (30 to 12 species). Large-bodied birds were particularly prone to extinction before 1987, but following this time none of the species traits we studied could be considered predictive of extinction proneness. All seven forest-dependent bird species that attempted to colonize this woodlot by 1987 perished thereafter. Our results show that area reduction, isolation, intense human use, and perverse management (e.g., understory removal) of this patch have probably negatively affected the long-term sustainability of its forest avifauna.     

Demographic Limitations of the Ability of Habitat Restoration to Rescue Declining Populations

Abstract:  Habitat restoration is often recommended in conservation without first evaluating whether populations are in fact habitat limited and thus whether declining populations can be stabilized or recovered through habitat restoration. We used a spatially structured demographic model coupled with a dynamic neutral landscape model to evaluate whether habitat restoration could rescue populations of several generic migratory songbirds that differed in their sensitivity to habitat fragmentation (i.e., severity of edge effects on nesting success). Simulating a best-case scenario, landscapes were instantly restored to 100% habitat before, at, or after habitat loss exceeded the species' vulnerability threshold. The vulnerability threshold is a measure of extinction risk, in which the change in population growth rate ( δλ ) scaled to the rate of habitat loss ( δh ) falls below −1% ( δλ/δh ≤ −0.01). Habitat restoration was most effective for species with low-to-moderate edge sensitivities and in landscapes that had not previously experienced extensive fragmentation. To stabilize populations of species that were highly edge sensitive or any species in heavily fragmented landscapes, restoration needed to be initiated long before the vulnerability threshold was reached. In practice, habitat restoration is generally not initiated until a population is at risk of extinction, but our model results demonstrate that some populations cannot be recovered at this point through habitat restoration alone. At this stage, habitat loss and fragmentation have seriously eroded the species' demographic potential such that halting population declines is limited more by demographic factors than the amount of available habitat. Evidence that populations decline in response to habitat loss is thus not sufficient to conclude that habitat restoration will be sufficient to rescue declining populations.