利用车载激光扫描的城市森林三维绿量估算

针对城市森林绿量估算研究不足的现状,该文提出了结合高分辨率航空遥感影像和车载激光扫描技术估算城市森林三维绿量的方法:首先从车载激光扫描数据中提取道路两侧单株树的生物物理参数,再结合从航空遥感影像中提取的植被分布,对均质城市森林片区进行三维绿量的拟合计算;最后以上海市滨江森林公园为例进行了方法验证。结果表明,该方法能够拓展车载激光扫描系统应用的领域,为城市绿化信息的获取提供参考。     

A field experimental study on recolonization and succession of subtidal macrobenthic community in sediment contaminated with industrial wastes

A field experiment was carried out in Hong Kong to study the patterns of recolonization and succession of subtidal macrobenthos in defaunated sediment contaminated with industrial wastes and to determine the time required for benthic recovery in the industrial-contaminated sediment. A total of 50 species was found with an average of 172 animals/tray and 24 species/tray recorded one month after deployment. Initial colonizers were predominantly polychaetes (96 animals/tray, accounting for 55.7%) and gastropods (47 animals/tray, accounting for 27.2%). Abundance of macrobenthos increased quickly to a peak (505 animals/tray) after four months, declined afterwards, and increased again till the end of the experiment. Species number peaked (57 species/tray) in the same month as abundance did, and gradually declined thereafter. Abundance, species number and diversity were significantly lower in the industrial-contaminated sediment as compared to the controls during the early successional stages, indicating the harmful effects of industrial wastes on recolonization and succession of macrobenthos. Although no significant differences in community parameters between the industrial-contaminated and the control sediments were found after eleven months, significant difference in species composition still existed after fourteen months, showing a relatively long-term impact of industrial wastes on macrobenthic community structure.     

Minneapolis and Its Environs

Abstract

University students participated in a research project on communities and conservation on Mount Kilimanjaro in Tanzania. Students contributed by gathering data with various methods that will be compiled in a GIS. Living in three villages at different elevations on the mountain, students facilitated GPS mapping, a random survey of over 90 households, and recording of observations and interviews with the people of these villages. While the inclusion of students in the research project brought greater logistical demands, their participation allowed quick collection of data on a broad scale, more intimate knowledge of the three villages and the communities in them, and provided a valuable learning experience for the students with opportunities to develop and carry-out a research project in an international setting.     

Involvement Geography: The School Partnership Program In The Junior High School

Abstract

This article presents a family program that extends the materials and meeting times of the Michigan Model Family Geography Challenge, including suggestions on creating a successful family night program. The article focuses on developing positive school-community relationships by inviting local community members to participate in fun academic lessons. In addition to watching the news together nightly, families meet four times during an eight-week period to engage in hands-on geography related activities. One lesson is introduced during each session and families work together to complete assigned tasks. Following the activity, families join together to eat and socialize. The program enhances geographic knowledge (including current events), positive family interactions, and school outreach.     

新疆阿勒泰地区不同盐池大型底栖动物的群落结构

 2008年7月～2009年5月,分别于平水期（7月）、枯水期（10月）和丰水期（5月）对新疆阿勒泰地区5个盐池进行了大型底栖动物及相关环境因子的调查,共采集到底栖动物23种,其中水生昆虫18种,软体动物4种,环节动物1种。优势种为羽摇蚊（IV=59.00%）、水蝇幼虫（IV=6.86%）、扁蜷螺（IV=6.67%）、Diplocladius sp.(IV=4.69%）和卵萝卜螺（IV =4.34%）。新疆阿勒泰地区盐池大型底栖动物的平均密度和生物量分别为316.36±117.27 ind/m2和4.09±2.73 g/m2。对大型底栖动物和相关环境因子的CCA分析结果显示,新疆阿勒泰地区盐池大型底栖动物物种分布在很大程度上受到环境因子的影响,种类与环境因子排序轴的相关系数高达0.992和0.990。盐度和电导率是影响大型底栖动物分布的两个主要因子,海拔、pH和温度对大型底栖动物的分布也有一定程度的影响。     

大规模三维植被场景实时可视化方法

采用L系统结合野外观测数据来构建植被单体的三维结构模型,根据植被模型特点,分别对枝干和树叶两个组成部分进行几何简化,大幅度减少模型所需的几何要素数量。在冠层模型简化中,提出了分层LOD模型提取方法,该方法可以高效提取出多复杂度的冠层LOD模型,同时保证组成LOD模型的每片叶子都符合最小化误差方程的要求。在实时渲染过程中...     

广州保障性住区的社会空间特征

城镇保障性住房制度直接塑造了保障性住区,这一“国家化”的社会空间在不同的城市呈现出迥异的类型。通过梳理城镇保障房制度的演变及在广州的实施,将广州的保障性住区分为四类:1986～1998年建成的承接单位体制内住房困难户的住区、1999～2005年建成的承载党政机关和教医系统住房困难家庭的住区、2006年后新建的主要承载具有城市户籍的社会双困群体的住区、建设历程跨越多制度阶段的承载多类保障群体的综合住区;通过“典型案例”研究,各类保障住区的现状社会空间可归纳为:“类西方‘社会型’公共住区的极度贫困均质空间”、“介于中国城市普遍存在的贫困集聚区的‘贫困混杂空间’和西方混合社区的‘有序混合空间’之间但混杂性高的贫困空间”、“介于两者之间但有序性强的混合空间”、“类商品房住区”的均质非贫困空间。     

九龙甸水源区桉树林与云南松土壤特性比较

通过参照本土云南松次生林土壤的性质,对外来的不同生长段桉树林土壤进行系统的物理性质分析,揭示桉树种植对土壤结构的改造过程。测定结果分析表明：相对于云南林次生林,不同生长段的桉树林土壤在容重、细颗粒含量上表现出较高值;而自然含水量、饱和含水量、总孔隙度、毛管孔隙度、有机质含量等值却很小。因此,桉树种植改变了本土植被下形成的土壤,导致土壤结构状况变差。     

林窗对格氏栲天然林更新层物种竞争的影响

采用Hegyi单木竞争指数模型探讨林窗和林下格氏栲(Castanopsis kawakamii)幼苗幼树种内和种间竞争强度,分析林窗对格氏栲天然林更新层物种竞争的影响。结果表明:随着对象木高度的增加,林窗和林下格氏栲幼苗幼树的种内竞争强度逐渐减少。林窗种间竞争强度的顺序为:梨茶(Camellia octopetala)>褐毛石楠(Photinia hirsuta)>黄润楠(Machilus grijsii)>桂北木姜子(Litsea subcoriacea)>毛鳞省藤(Calamus thysanolepis)>酸味子(Antidesma japonicum)>少叶黄杞(Engelhardtia fenzelii)>矩圆叶鼠刺(Itea chinensis)>小叶赤楠(Syzygium grijsii)>山黄皮(Clausena dentata)>光叶山矾(Syplocos lancifolia)>沿海紫金牛(Ardisia punctata)>丝栗栲(Castanopsis fargesii)>狗骨柴(Diplospora dubia)>木荷(Schima superba)>赤楠(Syzygium buxifolium)>杜茎山(Maesa japonica)。林下种间竞争强度的顺序为:桂北木姜子>梨茶>黄润楠>木荷>毛冬青(Ilex pubescens)>狗骨柴>毛鳞省藤>香港新木姜子(Neolitsea cambodiana)>酸味子>沿海紫金牛>山黄皮>光叶山矾>赤楠>小叶赤楠>尖叶水丝梨(Distyliopsis dunnii)>杜茎山>丝栗栲。格氏栲幼苗幼树的竞争主要来自种间竞争,种内竞争对格氏栲影响不大,林窗格氏栲幼苗幼树的种内竞争强度和种间总体竞争强度大于林下。通过筛选林窗和林下格氏栲对象木树高与竞争强度的竞争模型,发现对象木树高与竞争指数之间存在负相关,预测结果表明,在林窗格氏栲幼苗生长初期应加强对其保护,林下格氏栲幼苗高度达到100～150 cm后适当采取创造林窗环境以实现其快速生长,从而有效促进林窗和林下格氏栲种群的保护与更新。     

基于GIS和视频监控的森林防火指挥决策系统研建

森林火灾能对森林资源造成巨大的危害,因此发现林区火源并进行科学决策具有重要意义.本系统数据主要包括1∶1万地形图、1∶1万森林资源二类调查数据、扑火队分布数据、瞭望台站数据、扑火物资储备数据、林业局管理机构分布数据、研究区2010年landsat TM遥感影像图等;系统功能主要包括数据的处理和管理、森林火灾监测、最佳扑火路径分析、防火扑火预案制定和决策、森林火险等级评价、林火趋势模拟和预测、灾害损失评估、相关图表和报告制作等.系统采用Microsoft Visual Studio 2005(C#)作为开发语言,基于Arc Engine 9.3组件进行二次开发,三维地图显示采用skyline Terra Explorer开发平台,数据库采用SQL Server 2005数据库管理系统,利用Arc SDE 9.3空间数据库引擎对空间数据进行管理.