A Freshwater Classification Approach for Biodiversity Conservation Planning

Abstract:  Freshwater biodiversity is highly endangered and faces increasing threats worldwide. To be complete, regional plans that identify critical areas for conservation must capture representative components of freshwater biodiversity as well as rare and endangered species. We present a spatially hierarchical approach to classify freshwater systems to create a coarse filter to capture representative freshwater biodiversity in regional conservation plans. The classification framework has four levels that we described using abiotic factors within a zoogeographic context and mapped in a geographic information system. Methods to classify and map units are flexible and can be automated where high-quality spatial data exist, or can be manually developed where such data are not available. Products include a spatially comprehensive inventory of mapped and classified units that can be used remotely to characterize regional patterns of aquatic ecosystems. We provide examples of classification procedures in data-rich and data-poor regions from the Columbia River Basin in the Pacific Northwest of North America and the upper Paraguay River in central South America. The approach, which has been applied in North, Central, and South America, provides a relatively rapid and pragmatic way to account for representative freshwater biodiversity at scales appropriate to regional assessments.     

可持续发展视角下自然资源的定量化动态分类研究

从可持续发展的基本思路出发 ,对资源的分类原理做了系统的分析 ,提出了基于自然资源动态分类的定量化定义公式 ,并做了分类对比。该方法为可持续发展由定性向定量化发展提供了依据 ,为利用信息高速公路技术对可持续发展的研究以及自然资源信息共享奠定了基础。     

Analyzing injury severity factors at highway railway grade crossing accidents involving vulnerable road users: A comparative study

Objective: The main objective of this study is to identify the main factors associated with injury severity of vulnerable road users (VRUs) involved in accidents at highway railroad grade crossings (HRGCs) using data mining techniques.

Methods: This article applies an ordered probit model, association rules, and classification and regression tree (CART) algorithms to the U.S. Federal Railroad Administration's (FRA) HRGC accident database for the period 2007–2013 to identify VRU injury severity factors at HRGCs.

Results: The results show that train speed is a key factor influencing injury severity. Further analysis illustrated that the presence of illumination does not reduce the severity of accidents for high-speed trains. In addition, there is a greater propensity toward fatal accidents for elderly road users compared to younger individuals. Interestingly, at night, injury accidents involving female road users are more severe compared to those involving males.

Conclusions: The ordered probit model was the primary technique, and CART and association rules act as the supporter and identifier of interactions between variables. All 3 algorithms' results consistently show that the most influential accident factors are train speed, VRU age, and gender. The findings of this research could be applied for identifying high-risk hotspots and developing cost-effective countermeasures targeting VRUs at HRGCs.     

Intercomparison of Satellite Remote Sensing‐Based Flood Inundation Mapping Techniques

The objective of this study was to determine the accuracy of five different digital image processing techniques to map flood inundation extent with Landsat 8–Operational Land Imager satellite imagery. The May 2016 flooding event in the Hempstead region of the Brazos River, Texas is used as a case study for this first comprehensive comparison of classification techniques of its kind. Five flood water classification techniques (i.e., supervised classification, unsupervised classification, delta‐cue change detection, Normalized Difference Water Index [NDWI], modified NDWI [MNDWI]) were implemented to characterize flooded regions. To identify flood water obscured by cloud cover, a digital elevation model (DEM)–based approach was employed. Classified floods were compared using an Advanced Fitness Index to a “reference flood map” created based on manual digitization, as well as other data sources, using the same satellite image. Supervised classification yielded the highest accuracy of 86.4%, while unsupervised, MNDWI, and NDWI closely followed at 79.6%, 77.3%, and 77.1%, respectively. Delta‐cue change detection yielded the lowest accuracy with 70.1%. Thus, supervised classification is recommended for flood water classification and inundation map generation under these settings. The DEM‐based approach used to identify cloud‐obscured flood water pixels was found reliable and easy to apply. It is therefore recommended for regions with relatively flat topography.     

城市垃圾分类的协同管理模式研究

通过对N市城市垃圾分类实践工作的梳理分析,构建了国家行动者与作为参与主体的居民之间协同管理的行动逻辑与运行模式:自上而下+自下而上的双向行动.一方面,国家行动者通过诱导性和强制性机制,增强居民参与到垃圾分类中的积极性;另一方面,社会参与者在接受国家政府指导的基础上,建立了社会力量主导的垃圾分类自治空间,发挥了"自下而上"的建构性作用.在中国迫切需要开展垃圾分类的背景下,该种运行模式将有助于城市垃圾分类工作的推进以及环境改善.     

不同再生水消毒方式对斑马鱼胚胎毒性的影响及其危害分级

以斑马鱼胚胎毒性测试研究海南某污水处理厂出水经氯胺、二氧化氯、次氯酸钠、臭氧和紫外几种消毒处理后对斑马鱼胚胎的毒性。利用胚胎毒性和层次分析法构建危害分级方法及其指标体系,评价消毒危害。研究结果表明:消毒处理前的二沉池出水未产生胚胎发育毒性效应,但经次氯酸钠、氯胺、臭氧、二氧化氯对再生水消毒处理可使斑马鱼胚胎出现卵黄囊异常、心跳减缓、色素沉积减少、孵出延缓和卷尾等毒理反应;不同消毒方式处理的再生水可致斑马鱼胚胎死亡率增加,胚胎毒性依次为:二氧化氯紫外紫外+次氯酸钠=二沉池出水(不消毒)氯胺=紫外+氯胺臭氧次氯酸钠;不同消毒方式的危害分级为:二氧化氯和紫外消毒构成轻微危害,危害等级为I级,紫外+次氯酸钠、紫外+氯胺、氯胺消毒构成中度危害,危害等级为II级,次氯酸钠危害较强,其危害等级为III级;化学消毒剂与紫外线组合消毒可降低再生水消毒的危害。     

一种改进的灾害新闻3要素提取方法研究*

为提取灾害性新闻中的基本要素,迅速掌握灾害事件信息和发展趋势,将目标分类和命名实体识别（named entity recognition,NER）相结合,提出改进的灾害新闻3要素提取方法。构建滑动窗检测器搭载不同的分类模型,实现对新闻文本的灾害主题识别与时空位置要素范围判定,结合命名实体识别完成对时空位置要素的精准提取,并以灾害事故信息文本为例进行测试。研究结果表明:通过在火灾、地震和滑坡新闻中进行数据集中测试,发现本文方法相较于LSTM,BILSTM,BILSTM-CRF提取效果更优;本文方法可对大量灾害性新闻的灾害3要素进行识别提取,对灾害信息进行时空规律分析,研究结果可在灾害应急响应中发挥重要作用。     

煤矿安全管理体系缺失和不安全行为研究

现阶段我国煤矿的安全技术、生产设备都有大幅提高,但事故发生率仍居高不下,其主要原因是安全管理体系的缺失和存在不安全行为。为预防事故的发生,研究煤矿安全管理体系和不安全行为是十分必要的。为此,构建适合分析煤矿安全管理体系缺失和不安全行为的HFACS框架。按照HFACS框架,采用SPSS13.0对515起煤矿伤亡事故发生的原因进行整理分类,运用χ2检验和让步比(OR)分析安全管理体系缺失情况,不安全行为发生的原因,以及两者之间的内在联系。研究结果表明,安全管理体系缺失主要表现在管理文化的缺失和监督不充分,不安全行为主要表现在决策差错和习惯性违规。安全管理体系缺失是导致不安全行为的潜在根本原因。     

环境保护“十二·五”规划——目标、任务与动力

围绕国家和自治区的总体要求,结合包头市实际,明确了包头市十二.五环境保护工作的指导思想、总体目标,以削减总量、改善质量、防范风险为主线,按环境要素提出了十二.五环境保护工作的重点任务和动力机制,为科学编制十二.五环境保护规划奠定了基础。     

Applying Satellite Imagery to Triage Assessment of Ecosystem Health

Considerable evidence documents that certain changes in vegetation and soils result in irreversibly degraded rangeland ecosystems. We used Advanced Very High Resolution Radiometer (AVHRR) imagery to develop calibration patterns of change in the Normalized Difference Vegetation Index (NDVI) over the growing season for selected sites for which we had ground data and historical data characterizing these sites as irreversibly degraded. We used the NDVI curves for these training sites to classify and map the irreversibly degraded rangelands in southern New Mexico. We composited images into four year blocks: 1988–1991, 1989–1992, and 1990–1993. The overlap in pixels classified as irreversibly degraded ranged from 42.6% to 84.3% in year block comparisons. Quantitative data on vegetation composition and cover were collected at 13 sites within a small portion of the study area. Wide coverage reconnaissance of boundaries between vegetation types was also conducted for comparisons with year block maps. The year block 1988–1991 provided the most accurate delineation of degraded areas. The rangelands of southern New Mexico experienced above average precipitation from 1990–1993. The above average precipitation resulted in spatially variable productivity of ephemeral weedy plants on the training sites and degraded rangelands which resulted in much smaller areas classified as irreversibly degraded. We selected imagery for a single year, 1989, which was characterized by the absence of spring annual plant production in order to eliminate the confounding effect of reflectance from annual weeds. That image analysis classified more than 20% of the rangelands as irreversibly degraded because areas with shrub-grass mosaic were included in the degraded classification. The single year image included more than double the area classified as irreversibly degraded by the year blocks. AVHRR imagery can be used to make triage assessments of irreversibly degraded rangeland but such assessment requires understanding productivity patterns and variability across the landscapes of the region and careful selection of the years from which imagery is chosen.