The Role of Observer Variation in Determining Rosgen Stream Types in Northeastern Oregon Mountain Streams1

Abstract: Consistency in determining Rosgen stream types was evaluated in 12 streams within the John Day Basin, northeastern Oregon. The Rosgen classification system is commonly used in the western United States and is based on the measurement of five stream attributes: entrenchment ratio, width‐to‐depth ratio, sinuosity, slope, and substrate size. Streams were classified from measurements made by three monitoring groups, with each group fielding multiple crews that conducted two to three independent surveys of each stream. In only four streams (33%) did measurements from all crews in all monitoring groups yield the same stream type. Most differences found among field crews and monitoring groups could be attributed to differences in estimates of the entrenchment ratio. Differences in entrenchment ratio were likely due to small discrepancies in determination of maximum bankfull depth, leading to potentially large differences in determination of Rosgen’s flood‐prone width and consequent values of entrenchment. The result was considerable measurement variability among crews within a monitoring group, and because entrenchment ratio is the first discriminator in the Rosgen classification, differences in the assessment of this value often resulted in different determination of primary stream types. In contrast, we found that consistently evaluated attributes, such as channel slope, rarely resulted in any differences in classification. We also found that the Rosgen method can yield nonunique solutions (multiple channel types), with no clear guidance for resolving these situations, and we found that some assigned stream types did not match the appearance of the evaluated stream. Based on these observations we caution the use of Rosgen stream classes for communicating conditions of a single stream or as strata when analyzing many streams due to the reliance of the Rosgen approach on bankfull estimates which are inherently uncertain.     

Object-Based Classification as an Alternative Approach to the Traditional Pixel-Based Classification to Identify Potential Habitat of the Grasshopper Sparrow

The traditional method of identifying wildlife habitat distribution over large regions consists of pixel-based classification of satellite images into a suite of habitat classes used to select suitable habitat patches. Object-based classification is a new method that can achieve the same objective based on the segmentation of spectral bands of the image creating homogeneous polygons with regard to spatial or spectral characteristics. The segmentation algorithm does not solely rely on the single pixel value, but also on shape, texture, and pixel spatial continuity. The object-based classification is a knowledge base process where an interpretation key is developed using ground control points and objects are assigned to specific classes according to threshold values of determined spectral and/or spatial attributes. We developed a model using the eCognition software to identify suitable habitats for the Grasshopper Sparrow, a rare and declining species found in southwestern Québec. The model was developed in a region with known breeding sites and applied on other images covering adjacent regions where potential breeding habitats may be present. We were successful in locating potential habitats in areas where dairy farming prevailed but failed in an adjacent region covered by a distinct Landsat scene and dominated by annual crops. We discuss the added value of this method, such as the possibility to use the contextual information associated to objects and the ability to eliminate unsuitable areas in the segmentation and land cover classification processes, as well as technical and logistical constraints. A series of recommendations on the use of this method and on conservation issues of Grasshopper Sparrow habitat is also provided.     

填埋场矿化垃圾的分选实验研究

针对上海市老港垃圾填埋场填埋龄为10年的矿化垃圾,选择了滚筒筛作为分选手段,并对其运行工况进行了研究。结果表明,开采出来的垃圾中可利用的细料占39％,可回收物质占22％,具有较高的回收利用价值。同时确定了实验用滚筒筛筛分矿化垃圾的孔径为40mm,最佳运行条件是v／V（v为滚筒实测转速,V为滚筒极限转速）为0．51-0．60、角度为4．5°-6．5°。     

GHS化学品危险性分类及其公示要素(下)

概述了全球化学品统一分类和标签制度（GHS）的产生背景、推行GHS的重要意义,介绍了GHS关于化学品危险性分类和公示要素的主要内容,评估了我国现行化学品危险性分类与GHS分类的差异点,并对我国全面实施GHS提出了若干对策建议。     

Testing the Hydrological Landscape Unit Classification System and Other Terrain Analysis Measures for Predicting Low-Flow Nitrate and Chloride in Watersheds

Elevated nitrate concentrations in streamwater are a major environmental management problem. While land use exerts a large control on stream nitrate, hydrology often plays an equally important role. To date, predictions of low-flow nitrate in ungauged watersheds have been poor because of the difficulty in describing the uniqueness of watershed hydrology over large areas. Clearly, hydrologic response varies depending on the states and stocks of water, flow pathways, and residence times. How to capture the dominant hydrological controls that combine with land use to define streamwater nitrate concentration is a major research challenge. This paper tests the new Hydrologic Landscape Regions (HLRs) watershed classification scheme of Wolock and others (Environmental Management 34:S71-S88, 2004) to address the question: Can HLRs be used as a way to predict low-flow nitrate? We also test a number of other indexes including inverse-distance weighting of land use and the well-known topographic index (TI) to address the question: How do other terrain and land use measures compare to HLR in terms of their ability to predict low-flow nitrate concentration? We test this for 76 watersheds in western Oregon using the U.S. Environmental Protection Agency’s Environmental Monitoring and Assessment Program and Regional Environmental Monitoring and Assessment Program data. We found that HLRs did not significantly improve nitrate predictions beyond the standard TI and land-use metrics. Using TI and inverse-distance weighting did not improve nitrate predictions; the best models were the percentage land use—elevation models. We did, however, see an improvement of chloride predictions using HLRs, TI, and inverse-distance weighting; adding HLRs and TI significantly improved model predictions and the best models used inverse-distance weighting and elevation. One interesting result of this study is elevation consistently predicted nitrate better than TI or the hydrologic classification scheme.     

Comparison of Chemical Concentrations in Mussels and Oysters from the United States and France

Results from two 'Mussel Watch'-type monitoring programs were compared: the Réseau National d'Observation de la qualité du milieu marin (RNO), the French monitoring network, and the Mussel Watch Project of the U.S. National Status and Trends (NS&T) Program. 80 RNO sites (47 for mussels and 33 for oysters) and 89 NS&T sites (45 for mussels and 44 for oysters) provided a basis for the comparison of median concentrations of commonly measured trace metals (mercury, lead, zinc, cadmium and copper) and organic chemicals. Lower lead and lindane concentrations in the U.S. were explained by their respective history of use. Differences in Zn and Cu, essential elements for both mussels and oysters, could be due to specific internal regulation processes. Higher cadmium concentrations in the U.S. are possibly related to U.S. coastal areas being richer in nutrients or to a lesser use of this element as a general anticorrosive in France. We could not find any plausible explanation for higher mercury concentrations in France. This first attempt of a comparison of national chemical monitoring programs raises the need for deeper understanding of possible contamination sources.     

全生命周期视角下中国建筑碳排放空间关联网络演化及影响因素分析

基于全生命周期视角核算2011~2019年中国省际建筑碳排放量,采用社会网络分析方法,探究碳排放空间关联网络演化及其影响因素.结果表明：①中国建筑碳排放空间关联网络形态明显存在,网络密度和网络关联数逐渐上升,网络紧密性和稳定性逐渐提高.②上海、浙江、天津、北京和江苏处于碳排放空间关联网络的核心和支配地位.③北京、天津、江苏、内蒙古、上海和山东属于“净受益”板块,接收其他地区的建筑碳排放;广东、重庆、福建和浙江属于“经纪人”板块,实现了建筑碳排放生产端和消费端的动态平衡;其余省份均扮演“净溢出”角色,主动向外省发出建筑碳排放量.板块间的关联关系远大于板块内部的关联关系.④经济发展、空间邻接关系、城镇化、建筑业过程结构和产业结构差异对建筑碳排放空间关联产生显著影响.研究结果可为建筑业区域协同减排提供参考.     

防噪耳塞综述及探讨

防噪耳塞体积小、功能全、成本低,广泛应用于生活生产。本文记述了防噪耳塞的产生及发展现状,总结了其技术指标,归纳了不同的耳塞种类及其降噪原理。在进一步发挥防噪耳塞的作用,减轻噪声污染,创新防噪耳塞设计原理及结构上进行了探讨,为防噪耳塞的研究和改进提出了自己的思路。     

基于突变理论的公共场所集群事件预警分级

针对公共场所集群事件,利用突变理论对其预警级别进行研究。选择2005—2008年发生的具有比较典型的集群事件为样本;考虑公共建筑饱和度、人群情绪指标、建筑管理指标和安全事故隐患等因素建立指标体系;运用尖点突变和蝴蝶突变模型进行突变级数的分析和评价,得到预警分级突变级数的大致范围;并运用一个公共场所集群事件发生时预警级别判断的实例进行说明。实例表明,利用突变理论模型,可以为公共场所管理者在人群安全监控决策方面提供初步的预警信息。     

“积木式做法”研究及对我国实施GHS范围的建议

从分析我国实施GHS的问题出发,详细研究GHS的"积木式做法",指出实施GHS可以根据实际情况有选择地采用其危险性分类。同时分析我国现阶段化学品相关实验室技术支撑能力,结合目前化学品监管范围,提出实施GHS的重点,要先实现我国化学品监管范围与GHS相关危险性的分类统一,再逐步将GHS其他危险性分类引入我国危险化学品监管范围,并对现阶段实施GHS的危险性种类和类别提出启动物理化学性质引起的危险、急性毒性和皮肤腐蚀/刺激性、危害水生环境分类标准的实施工作建议。