共查询到19条相似文献，搜索用时 156 毫秒
1.
2.
3.
基于PCI的SPOT5遥感影像正射校正方法分析 总被引：1，自引：0，他引：1
正射校正是各种遥感应用过程中必不可少的基础工作,对于某些地形起伏较大、常规的几何校正难以消除由此引起的几何变形的影像,有必要进行正射校正。正射校正的方法很多,以攸县黄丰桥林场柏市分场为研究区,以SPOT5高分辨率遥感影像为校正数据进行正射校正,采用Satellite Orbital Mod—elling模型和Rational Functions模型,针对不同方法所产生的正射影像图精度以及运算速度进行比较与分析。实验结果表明：在相同的控制点条件下,对于SPOT5数据来说,Satellite Orbital Modelling模型的精度更高,但是此模型计算速度相对稍慢一点。该研究对SPOT遥感影像能更正确地选择正射校正方法提供参考。 相似文献
4.
基于Spot5卫星遥感数据的正射影像图制作探讨 总被引：1，自引：0，他引：1
目前广泛应用于森林资源调查中的正射影像图具有很多线划图无法比拟的优点,地理信息真实、直观、信息量丰富.文章对利用遥感图像处理系统软件ERDAS IMAGINE制作Spot 5卫星正射影像图的原理、方法和流程进行阐述,并着重论及了技术要点和关键环节. 相似文献
5.
6.
林地落界就是依据现有森林资源规划设计调查、公益林区划界定以及国土资源详查和区划等成果,以数字正射影像图（简称DOM）数据信息为基础,通过遥感影像资料判读核实,并辅以适当的现地调查,按照林地落界基本条件和精度要求,落实现有林地和依法可用于发展林业的其他土地的边界和图斑及林地保护利用方向。 相似文献
7.
采用正射影像图为森林资源二类调查调绘的基本信息源 ,并结合野外实地验证 ,进行了内蒙古扎兰屯市林业局森林资源二类调查工作 ,查清了该市森林资源的种类 ,数量和质量 ,达到了预期目的 相似文献
8.
9.
10.
11.
溶解性有机质(D0M)是森林土壤的重要组成部分,虽然在森林土壤中占比较低,但其是流动力最强且循环最为活跃的有机质组分,同时具有重要的生态环境效应。文章综述了近几年来国内外关于森林土壤DOM的研究进展,包括森林土壤DOM的主要来源、含量及其组成;pH值、温度、湿度、森林凋落物的数量、质量等对森林土壤DOM含量的影响;森林土壤D0M可能引发的水体富营养化、激发温室效应、提高土壤肥力等其他的生态环境效应,并对森林土壤DOM今后的相关研究进行了展望。 相似文献
12.
论述了淡水环境中可溶有机质(DOM)在分离与分析方法、来源与特征,以及环境意义等方面的研究进展。指出了在分离方法上,从XAD树脂分离到反渗透膜分离已经发展出各种分离技术;在分析方法上,现代波谱分析技术得到了广泛应用。DOM是由在来源、年龄、存在状态、后生改造等方面存在巨大差异的不同有机质混合构成的,因而呈现出十分复杂的非均质结构。DOM通过其自身的生物可利用性、改变有机污染物和重金属的生物可利用性及其耗氧能力影响环境质量,而且其自身的一些地球化学特征也能用来反映环境的变化特点。最后简述了湿地淡水环境中DOM的研究趋势和展望。 相似文献
13.
土壤可溶性有机质研究进展 总被引：1，自引：0，他引：1
可溶性有机质（DOM）是陆地生态系统重要的活性碳源和养分库,在土壤有机质的降解和矿化过程中发挥着关键作用,决定着土壤微生物区系和土壤生物学活性,在森林生态系统生命元素的生物地球化学物质循环中具有重要作用。本文介绍可溶性有机质的基本概念及其研究方法,分析和探讨可溶性有机质的影响因素及其发展趋势。 相似文献
14.
Akiko Sasaki Shozo Shikenya Kazuhiko Takeda Takayuki Nakatsubo 《Journal of Forest Research》2007,12(1):68-74
To estimate the importance of leaching of dissolved organic matter (DOM) as a pathway through which organic matter is supplied
to stream ecosystems, we examined the amount of leachate over time and chemical properties of DOM leached from leaves in different
conditions. The samples used were green leaves, yellow senescent leaves, and leaf litter of Salix gracilistyla Miq., which is the dominant riparian plant species in the middle reaches of rivers in western Japan. We analyzed dissolved
organic carbon (DOC), total sugar, and polyphenol in the leachate of leaf samples collected from a fluvial bar in the middle
reaches of the Ohtagawa River in Hiroshima Prefecture, Japan. Considerable leaching of DOC from senescent leaves [37.3 mg g−1 dry weight (dw) leaf] and leaf litter (8.1 mg g−1 dw leaf) occurred within 24 h after immersion. In contrast, DOC leached from green leaves was negligible until 1 week after
leaf immersion. Carbon loss of leaves by leaching within 24 h after leaf immersion was estimated to be less than 8%, suggesting
that leaching of DOC from S. gracilistyla leaves is a minor pathway through which organic matter is supplied to stream ecosystems. DOM leached from the leaves included
sugar and polyphenol, which were among the major chemical forms of DOM leached from the leaves (based on the molecular mass).
In a laboratory experiment in which the difference in the stability of DOM between the chemical forms was examined, sugar
decomposed more rapidly than polyphenol. 相似文献
15.
The nature of different forest plant litters and the effect of their degradation processes on the properties of soil dissolved organic matter is a very important environmental issue in protected areas such as the “Natural Oriented Reserve Bosco delle Pianelle” in Southern Italy, Chemical and spectroscopic techniques were used to evaluate the influence of four different tree covers on the properties of dissolved organic matter (DOM) isolated from litter and surface soil layers. Fourier transform infrared spectroscopy analysis showed that all litter samples feature a prevalent aromatic character. Ligninolitic components of litters produced by Pinus halepensis L. and a mixture of Quercus trojana Webb. and Q. ilex L. were more degraded than those produced by either Q. ilex or a mixture of Carpinus betulus L. and C. orientalis Miller. The larger C/N ratios of the former litters might account for the greater degradation. Further, a lesser lignin decomposition was shown also for the latter samples, likely due to adverse topographical factors, such as less intense sunlight and greater moisture content. Spectroscopic analysis of litter DOM showed that easily degraded components, such as water-soluble compounds and carbohydrates, were preferentially degraded resulting in DOM that was enriched in lignin-derived compounds. Fluorescence analysis data of all litter DOM samples showed the occurrence of fluorescent units qualitatively similar regardless of plant covering, which suggests that in all cases simple structural components of low-molecular weight and small degree of aromatic polycondensation and content of conjugated chromophores are present. Soil DOM featured several numerous fluorescent units that differ as a function of the parent litter and/or its decomposition processes. Along the soil profiles water-soluble aliphatic compounds of low-molecular weight are found down to the deepest layer, whereas aromatic–ligninolitic compounds are decreasing with depth, probably because of their adsorption by mineral soil components. A greater amount of aromatic units, likely lignin-derived compounds, was found in the DOM from P. halepensis L., which suggested a more extended lignin decomposition. Further, with increasing soil depth, DOM was characterized by a decrease of low-molecular weight organic molecules and lower degree of humification. 相似文献
16.
Róbert Gallé Nikolett Gallé-Szpisjak Attila Torma 《European Journal of Forest Research》2017,136(1):51-58
Plantation forests comprise an important part of the forested areas in European countries. Intensive forestry management and short-rotation cycles of plantation forests reduce habitat diversity and change the composition of invertebrate assemblages, mainly by reducing the number of habitat specialist species. Here, we analysed the effect of vegetation structure, amount of dead organic matter (DOM) and plantation age on spider functional diversity and assemblage structure in short-rotation plantations of native silver poplar in Hungary. Three stages, representing young plantations, 6- to 10-year-old stands (five stands), middle-aged plantations, aged between 23 and 26 years (five stands) and mature, 35- to 37-year-old forests at commercial maturity (five stands) were sampled. Each sample consisted of the data of ten pitfall traps. Traps were installed 5 m from each other in a 2 × 5 grid. Functional diversity was positively related to vegetation structure. High functional diversity indicates a higher number of available niches and potential resources. The abundance of moist habitat species and forest specialist species was positively correlated with DOM. Furthermore, moist habitat species were also related to vegetation structure. The most important environmental parameters affecting spiders were factors attributed to trees (litter and DOM), understory vegetation structure and, to a lesser extent, forest age. Different-aged stands may be similar in terms of species composition of their spider fauna if they comprise the same habitat structural patterns. Our study emphasises that the simple habitat structure of plantation forests has a negative effect on spider communities. 相似文献
17.
公路工程建设是国家基础设施建设的重要组成部分，选线设计是公路工程建设和工程质量保证的关键，其技术含量高，覆盖专业面广，对高新技术手段的应用要求也越来越全面。遥感技术（RS）、地理信息系统技术（CIS）、全球定位系统技术（CPS）、数字地面模型技术（DTM）、数字正射影像（DOM）和计算机辅助设计（CAD）在公路工程的规划、勘探和设计中也越来越重要。本文全面总结了公路工程遥感的应用特点，遥感技术在公路选线上的优势，说明了在公路勘探设计的工可研阶段遥感所能发挥的作用。 相似文献
18.
真实三维场景可真实地反映森林景区的地形地貌特征,为森林景区科学管理、生态监测、景观规划及虚拟可视化等提供数据支撑和技术依据。文章以南岭国家森林公园为例,分析了复杂高山地形特征和无人机特性,研究一种利用复合翼无人机对高山景区进行影像采集,建立实景三维模型、表面模型DSM和正射影像图DOM的方法,实现对南岭森林景区75 km~2真实三维场景构建,对场景精度和成果应用进行了分析。结果表明,利用复合翼无人机进行高山景区航拍,既解决了起飞降落问题,又提升了航拍时效性和可靠性;突破传统二维成果的局限性,提供三维模型、DSM和DOM等成果,提升景区可视化管理、森林调查及应用分析等能力。 相似文献
19.