江西泰和县森林生态系统水源涵养功能评估

森林生态系统综合水源涵养能力是林冠层、枯落物层和土壤层蓄水能力的总和。本文根据江西泰和县 2003 年森林资源二类调查,结合文献收集,从3 个作用层评估了泰和县森林生态系统的水源涵养量及其空间分布格局,比较了不同森林类型、林龄、海拔、坡度下的林冠降雨截留能力,枯落物最大持水量和土壤蓄水能力。结果表明,林冠层平均截留率为16.31%,枯落物层持水率为2.14%,土壤层蓄水率为81.55%,3 个层次总截留和蓄水量为1.41 亿m³。各种森林类型水源涵养量由大到小依次为：杉木林>马尾松林>湿地松林>阔叶林>毛竹林>灌木林> 混交林>经济林。幼林龄、中林龄、近熟林、成熟林和过熟林水源涵养贡献率分别为17.58%、65.39%、14.18%、 2.48%和0.37%,涵养水源能力随林龄的增加而增加。空间上,泰和县森林生态系统的综合水源涵养力表现出从东西两侧向中部递减的分布。不同立地条件下林分的合理经营与管理对于整个森林生态系统水源涵养功能的发挥具有重要的作用。     

2008年春季中国南方冰雪冻害林木折损分析

An abrupt ice and snow storm disaster which occurred in the spring of 2008 severely destroyed forests over a surprisingly large portion of southern China. A transect crossing Jinggang Mountain-Jitai Basin-Yushan Mountain-Wuyi Mountain was selected as the study area. The authors integrated field data collected in two field surveys to analyze the impacts of the disturbance on forests. The following results were obtained. (1) The extent of damage to plantations along the transect decreased in the order of slash pine > masson pine > mixed plantation > Chinese fir. Slash pine is an introduced species from southern America which is characterized by fast growth, low wood quality and rich oleoresin, and showed a damage rate of 61.3% of samples, of which 70.4% cannot recover naturally. Masson pine is the native pioneer species of forests with harder wood, and 52.5% were damaged due to turpentine, of which 60.9% cannot recovery naturally. Chinese fir is a local tree species and samples showed a rate of 46% and a relative rate of 32.5%, lower than the mixed plantation. (2) From west to east along the transect, we can see that evergreen broad-leaved forest of the western transect on Jinggang Mountain showed the lightest damage extent, and a Cryptomeria plantation at an altitude of 700 m was severely destroyed while Chinese fir showed light damage below 700 m and relatively severe damage above 900 m. Masson pine and slash pine in the central transect in Jitai Basin were damaged severely due to turpentine activities, and closed natural secondary deciduous broad-leaved forest was damaged severely due to high ice and snow accumulation on intertwined shrubs. Masson pine aerial-seeding plantations below 400 m along the eastern transect in Xingguo and Ningdu counties were nearly undamaged for small tree sizes, and Chinese fir at 500-900 m altitude showed a lighter damage extent. However, masson pine which was distributed above 400 m and planted in the 1960s, was severely damaged due to turpentine.     

远洋渔船动态监控系统研究

针对远洋渔业生产中的渔船监控问题,以卫星通讯、GIS、GPS、数据库等技术手段为支撑,进行了远洋渔船GPS动态监控系统的研究和开发工作。本文在介绍了系统总体框架的基础上,系统阐述了通讯文件的解包和数据质量的控制过程,并对渔船的动态监视和轨迹分析功能进行了论述。     

2008年春季中国南方冰雪冻害林木折损分析

An abrupt ice and snow storm disaster which occurred in the spring of 2008 se-verely destroyed forests over a surprisingly large portion of southern China.A transect crossing Jinggang Mountain-Jitai Basin-Yushan Mountain-Wuyi Mountain was selected as the study area.The authors integrated field data collected in two field surveys to analyze the impacts of the disturbance on forests.The following results were obtained.(1) The extent of damage to plantations along the transect decreased in the order of slash pine > masson pine > mixed plantation > Chinese fir.Slash pine is an introduced species from southern America which is characterized by fast growth,low wood quality and rich oleoresin,and showed a damage rate of 61.3% of samples,of which 70.4% cannot recover naturally.Masson pine is the native pioneer species of forests with harder wood,and 52.5% were damaged due to turpentine,of which 60.9% cannot recovery naturally.Chinese fir is a local tree species and samples showed a rate of 46% and a relative rate of 32.5%,lower than the mixed plantation.(2) From west to east along the transect,we can see that evergreen broad-leaved forest of the western transect on Jinggang Mountain showed the lightest damage extent,and a Cryp-tomeria plantation at an altitude of 700 m was severely destroyed while Chinese fir showed light damage below 700 m and relatively severe damage above 900 m.Masson pine and slash pine in the central transect in Jitai Basin were damaged severely due to turpentine ac-tivities,and closed natural secondary deciduous broad-leaved forest was damaged severely due to high ice and snow accumulation on intertwined shrubs.Masson pine aerial-seeding plantations below 400 m along the eastern transect in Xingguo and Ningdu counties were nearly undamaged for small tree sizes,and Chinese fir at 500-900 m altitude showed a lighter damage extent.However,masson pine which was distributed above 400 m and planted in the 1960s,was severely damaged due to turpentine.     

中国城市扩展对气温观测的影响及其高估程度

由于中国城市扩展导致部分气象站点被动进入城市内部,从而造成对区域气温的高估.本文利用遥感多期影像对中国700多个气象站点各历史时期的下垫面进行判别,得到"进城"站点及其进城时间.通过比较"进城"站点的观测数据和背景气温,计算出70年代以来"进城"气象站点上的平均热岛效应强度,并对热岛效应强度的季节性筹异进行了分析,得出70年代以来秋冬季节的热岛强度高于春季和夏季的结沦.通过比较真实气温和背景气温的空间数据,识别出了气温高估区域,得出中国东部地区的气温高估略高于中部地区,东部地区和中部地区的气温高估均远高于西部地区的结论.通过计算真实气温和背景气温序列的年平均气温变化趋势,得出近40年来全国的增温值约为1.58℃,其中凶城市扩展带来的增温贡献约为0.01℃,在气温高估的核心区域的贡献约为0.09℃.     

不同时间尺度的西北太平洋海洋表面温度距平模态的比较

本文利用经验正交分解法(Empirical Orthogonal Function,EOF)对不同月平均和10天平均的西北太平洋海洋表面温度距平数据进行分解,得到月平均和10天平均的西北太平洋海洋表面温度距平分布模态,并对分布模态进行比较。发现尽管数据源相同,但是不同时间分辨率的EOF结果出现正好相反的情况,文章最后从数学的角度解释了月平均和10天平均的海洋表面温度距平模态及其时间系数发生反向的原因。     

黄河源区玛多县土地利用/覆被及景观格局变化的遥感分析

采用了黄河源地区1977、1990及2003年MSS、TM的3个时相遥感影像,通过人机交互的解译与GIS的空间分析,提取了玛多县3个时期的土地利用/覆被信息。分析了玛多县各地类的数量变化和空间变化特征。另外对景观生态空间分布格局,利用FRAGSTATS软件对玛多县景观级别的动态特征进行了分析。结果表明:玛多县的土地利用/覆被类型以草地为主,占全区总面积77.93%;退化现象十分严重,主要是草地覆盖度的降低以及草地沙化;景观破碎化程度在前期呈下降趋势,而后期呈上升趋势,景观斑块形态越来越偏离规则而变得复杂、多样。     

海洋GIS数据模型与结构

探讨了海洋 GIS中的数据模型和数据结构问题。根据物理海洋学的研究方法 ,提出了海洋 GIS的数据表达模型。针对海洋 GIS中水体的特点 ,提出了适合海洋 GIS水体的多级化格网型数据结构 ,给出了两种大尺度海洋常用的格网化方案 :全球等角格网化方案和全球等面积格网化方案。这种格网型数据结构是普通 GRID的扩展 ,具有鲜明的海洋数据应用特色。     

迭代演进式GIS需求分析模型研究

需求分析是信息系统或软件开发生命周期中一个重要阶段，并具有自己的生命周期。需求分析具有迭代性、演进性和并行性三大特性。通常，需求分析方式隐含在各种系统开发模型中，20世纪90年代初以来，随着需求工程热潮的掀起，需求分析模型的研究也成为研究热点。Theofanos等在总结分析已有需求分析模式的基础上，提出了需求分析浪峰模型。该模型同时反映了需求分析的三个特性，刻画了需求分析的复杂性，充分体现了需求分析的发展新趋势。该文根据GIS特点，对该模型进行了三个方面的改进：（1）将需求分析划分为5个阶段，原模型中的需求定义分解为结构化定义和形式化定义两个阶段，以便于根据该模型进一步发展GIS分析的自动化工具；（2）进一步明确了需求分析每阶段的具体分析活动以及应该采用的分析方法，使模型更具可操作性；（3）反映了项目GIS、部门GIS、企业GIS、社会GIS等不同规模和复杂程度系统开发的需求分析的差别。并对不同情况下选择需求分析模式以及结构化需求定义方法进行深入的分析，对GIS系统开发的需求分析具有现实指导意义。     

三江源生态保护和建设一期工程生态成效评估

基于生态系统结构--服务动态过程趋势分析,针对生态保护与建设工程预期目标,构建了由生态系统结构,质量,服务及其变化因素构成的生态成效评估指标体系,研究发展野外观测,遥感监测和生态过程定量模拟一体化的监测评估技术体系,评估了三江源生态保护和建设一期工程的生态成效.结果表明:工程实施8年以来,三江源区宏观生态状况趋好但尚未达到1970s比较好的生态状况,草地持续退化趋势得到初步遏制但难以达到预期"草地植被盖度提高平均20%~40%"的目标,水体与湿地生态系统整体有所恢复,生态系统水源涵养和流域水供给能力提高,区域水源涵养量达到了增加13.20亿m³目标;重点工程区内生态恢复程度好于非工程区,除了气候影响以外,工程的实施对促进植被恢复具有明显而积极的作用;然而,草地退化局面没有获得根本性扭转,工程实施尚未遏制土壤水蚀增加趋势,一期工程局部性和初步性特点突显出三江源区生态保护任务的长期性和艰巨性.