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1.
首先给出CO2 倍增下遥感光合作物产量的概念模型,之后分析未受CO2 倍增的遥感光合作物产量估测模型;在考虑CO2 倍增对作物产量的影响后,对影响干物质累积的作物光合速率的模型进行修正,进而修正遥感光合作物产量估测模型。建立CO2 倍增下作物产量响应模型,求取各参数,并在CO2 倍增下对我国华北地区冬小麦产量响应进行填图,表明模型的估测结果有良好的可比性。  相似文献   

2.
基于中巴02B星遥感数据的油菜识别技术研究   总被引:1,自引:0,他引:1  
利用中巴02B星遥感资料,采用光谱分析法分析油菜作物的光谱反射特性,建立油菜作物遥感信息识别模型,并利用该模型对云南省罗平县油菜作物进行信息提取研究。结果表明,该油菜作物识别技术可为了解我国油菜种植情况、进行长势监测和产量估测提供技术参考。  相似文献   

3.
针对中国开展的国外农作物产量遥感估测大多依靠中低分辨率耕地信息、省级(州级)或国家级作物产量统计数据的现状,本文以美国玉米为例,探讨利用多年中高分辨率作物分布信息、时序遥感植被指数和县级作物产量统计数据开展国外重点地区作物单产遥感估测技术研究,以期进一步提高中国对国外农作物产量监测精度和精细化水平。首先,利用美国农业部国家农业统计局(NASS/USDA)生产的作物分布数据(CDL)获得多个年份玉米空间分布图,并对相应年份250 m分辨率16天合成的MODIS-NDVI时序数据进行掩膜处理,统计获得每年各县域内玉米主要生育期NDVI均值;其次,以各州为估产区,以多年县级玉米统计单产和县域内玉米主要生育期NDVI均值为基础,建立各州玉米主要生育期NDVI与玉米单产间关系模型;然后,通过主要生育期玉米单产和玉米植被指数间拟合程度,筛选确定各州玉米最佳估产期和最佳估产模型。最终,利用最佳估产模型实现美国各州玉米单产估测和全国玉米单产推算。其中,建模数据覆盖时间为2007年—2010年,验证数据为2011年。结果表明,应用最佳估产模型的2011年美国各州玉米单产估测相对误差在-4.16%—4.92%,均方根误差在148.75—820.93 kg/ha,各州估测结果计算获得全国玉米单产的相对误差仅为2.12%,均方根误差为285.57 kg/ha。可见,本研究的作物单产遥感估测技术方法具有一定可行性,可准确估测全球重点地区作物单产信息。  相似文献   

4.
生物量估测模型中遥感信息与植被光合参数的关系研究   总被引:47,自引:0,他引:47  
张佳华  符淙斌 《测绘学报》1999,28(2):128-132
本文通过对建立估测植被生物量遥感模型中所涉及的遥感信息参数与植被光合参数的关系分析,从理论和实验中阐明了反映植物长势的量发化植被指数和反映植物光合面积的叶面积指数,光合有效辐射及吸收光合有效辐射的相互关系,对在实际中建立更为机理的生物量遥感模型提供可供进一步参考的依据。  相似文献   

5.
叶面积指数(leaf area index,LAI)作为植被冠层的重要参数,对作物长势监测及产量估算具有重要意义。本研究以黑河流域张掖绿洲试验区为例,基于机载航空高光谱遥感影像(compact airborne spectrographic imager,CASI)数据,利用物理模型与统计模型对研究区的LAI进行估测反演。首先,利用归一化植被指数(normalized difference vegetation index,NDVI)与相应实测LAI数据建立最佳线性回归模型;然后,基于混合像元分解模型和多次散射植被冠层模型构建物理模型;最后,以线性回归模型为参比修正多次散射植被冠层模型,构建半经验LAI反演模型,并比较上述模型拟合效果。研究结果表明,半经验模型为绿洲区LAI反演最优模型,模型估算精度R2达到0.89,精度提高较显著。研究对提升作物LAI的估算精度有一定意义,并将进一步推动精细农业定量遥感理论的研究与应用。  相似文献   

6.
遥感技术在主要粮食作物估产中的应用   总被引:3,自引:0,他引:3  
张东霞  张继贤  常帆  梁勇 《测绘科学》2014,39(11):95-98,103
文章分析了国内外遥感技术在主要粮食作物估产中应用现状,探讨了遥感技术在作物估产领域的研究进展,研究了作物气候产量预报模型、遗传算法结合神经网络模型、基于人机交互的反演模型、基于决策树分类的县域估产模型、单产估测模型、基于SCE_UA算法的CERES_Wheat模型、雷达遥感估产模型等在我国主要农作物估产中的应用;分析表明遥感关键技术及模型选择为农作物估产精度的提高提供了重要的技术支持.最后对作物估产遥感技术发展趋势及农业信息化相关技术做了展望,指出综合遥感与计算机技术开发自动化系统、推进物联网与遥感技术结合等问题,是进一步的研究趋势.  相似文献   

7.
用蒙特-卡罗方法计算大气点扩散函数   总被引:8,自引:0,他引:8  
徐希孺  王平荣 《遥感学报》1999,3(4):268-278
大气效应的纠正是一个仍未被彻底解决的定量遥感问题,随着遥感器空间分辨率的不断提高,各种斜视星勒遥感不断涌现,寻找交叉辐射项的修正方法日显迫切,该文应用蒙特-卡罗(M-C)方法求得不同大气条件下的点扩散函数图形,结果显示:(1)大气状况对点扩散函数的形状、目标像元的贡献率有不可忽略的影响;(2)一次散射的假定将导致背景像元的贡献率,其绝对误差最大可达7%,其相对误差最大可达40%;(3)斜视条件下与  相似文献   

8.
根据东湖多年监测数据分析,建立了多元相关预测模型、基于灰色理论灰色系统的预测模型和质量平衡模型。为了提高灰色预测精度,利用残差对模型进行了相应的修正,并利用3种模型对影响东湖水质主要因子-经济、人口、BOD、COD、TN、TP进行了2000的预测,提出了东湖污染防治对策。  相似文献   

9.
复杂背景下被动FTIS定量遥感污染云团光谱   总被引:5,自引:0,他引:5  
张骏  荀毓龙 《遥感学报》1998,2(2):89-93
本文提出复杂背景下定量遥感污染云团光谱的算法。利用被动傅里叶变换红外光谱仪(FTIS)遥测目标气体和背景光谱数据及最小平方误差拟合方法,成功地解决了探测目标气体柱数密度和目标气体等效辐射温度。该处理方法不仅可用于特定污染云团的定量处理,而且可用于多种污染地区如发电厂、机场、城市交叉路口、垃圾处理站等对CO,CO2,NO,NO2,N2O,NH3,CH4,SO2,H2O,HCI和HCHO等气体浓度的监测。最后,详细讨论了用该算法对模拟剂的处理结果。  相似文献   

10.
大气影响是遥感定量化应用的主要障碍之一。本文首先分析了大气对遥感图像产生的各种影响并对影响程度进行了一般的阐述,然后在原理和方法上对典型的大气影响校正算法进行了总结。通过分析我们认为,为了校正遥感图像所受到的大气影响,定量地获取当时当地的大气条件是完成这一工作的必要条件,而且是非常重要的条件之一。为此,我们提出了利用NOAA星载垂直探测器资料即TOVS资料,结合使用气溶胶模型,通过大气辐射传输模型,建立地面辐射量与卫星测量值之间的关系,并完成了对NOAA-AVHRR图像的大气影响校正。在此基础上对我们的模型和算法进行了详细论述。这一模型是一套适用于发展业务软件的校正模型,软件发展完善后将为NOAA-AVHRR数据的定量化应用打下基础。  相似文献   

11.
目前,GIS技术已被广泛应用在野生动物生境研究中。但是,作为空间数据分析和处理工具,GIS缺乏进行启发式推理的能力。因此,与擅长于此的贝叶斯统计推理技术相结合则是解决这一问题的重要途径。以西双版纳纳板河流域生物圈保护区为试验区,综合应用GIS技术和多元统计技术建立印度野牛生境的两个逻辑斯蒂多元回归模型:趋势表面模型和环境模型,第一个模型的自变量是位置坐标,第二个模型的自变量是一组环境因子,然后应用贝叶斯统计合并这两个模型产生贝叶斯综合模型。结果表明,贝叶斯综合模型优于环境模型,可应用于野生动物生境概率评价。  相似文献   

12.
India has a rich repository of flora and fauna, but the rapid decline of wildlife and threat to its habitat has been a serious cause of concern. Hence, protected areas have been set up to achieve specific conservation objectives to facilitate timely and reliable information on forest types and its composition, degradation status and their suitability for different species of flora and fauna. In the present study, evaluation of tiger habitat in Corbett Tiger reserve is carried out using remote sensing, ground and other ancillary sources and is integrated using GIS using multi-criteria model. The results indicated that sal, mixed sal, miscellaneous forest, plantation, grassland, agriculture and scrub land are the major land use/land cover types and majority of the study area is covered under dense forest. Tiger habitat suitability analysis showed that large proportion of the area (51.4%) was found to be highly suitable followed by moderately suitable area (31%). Further, the correlation drawn between range-wise suitability area and actual tiger population in Corbett Tiger Reserve CTR indicated a positive correlation of 0.73. Disturbance to wildlife habitat, vegetation degradation and shrinking passage corridor are the major concern in CTR.  相似文献   

13.
With the progress of mobile GIS technology there is a great potential for adopting wireless communications and Internet mapping services for regional environmental management programs and natural habitat conservation. This paper provides an overview of a NASA-funded research project that focuses on the development of mobile GIS tools and wireless Internet Map Server (IMS) services to facilitate environmental monitoring and management tasks. By developing and testing wireless web-based map/image servers, mobile GIS applications, and global positional systems (GPS), this research created an integrated software/hardware infrastructure for a prototype mobile GIS application. The mobile GIS prototype allows multiple resource managers and park rangers to access large-size, remotely sensed images and GIS layers from a portable web server mounted in a vehicle. Users can conduct real-time spatial data updates and/or submit changes back to the web server over the wireless local area network (WLAN). This paper discusses in general the major components of mobile GIS, their current technological limitations, and potential problems during implementation. Key research agenda for mobile GIS are identified with suggestions for future research and development.  相似文献   

14.
Cellular Automata (CA) models at present do not adequately take into account the relationship and interactions between variables. However, land use change is influenced by multiple variables and their relationships. The objective of this study is to develop a novel CA model within a geographic information system (GIS) that consists of Bayesian Network (BN) and Influence Diagram (ID) sub‐models. Further, the proposed model is intended to simplify the definition of parameter values, transition rules and model structure. Multiple GIS layers provide inputs and the CA defines the transition rules by running the two sub‐models. In the BN sub‐model, land use drivers are encoded with conditional probabilities extracted from historical data to represent inter‐dependencies between the drivers. Using the ID sub‐model, the decision of changing from one land use state to another is made based on utility theory. The model was applied to simulate future land use changes in the Greater Vancouver Regional District (GVRD), Canada from 2001 to 2031. The results indicate that the model is able to detect spatio‐temporal drivers and generate various scenarios of land use change making it a useful tool for exploring complex planning scenarios.  相似文献   

15.
Recent environmental developments have stimulated an interest in conservation and restoration of the historical Willamette River flood plain, both to protect against flooding and to provide wildlife habitat. In order to best utilize scarce resources, we characterized historical and modern river channel and flood‐plain conditions to evaluate changes and help prioritize restoration sites. Using cartographic and photographic data sources, we developed a Geographic Information System (GIS) to map active channels, side channels, islands and tributaries for four separate dates, as well as riparian and flood‐plain vegetation characteristics for pre‐European settlement and modern time periods. Coverages based on flood records and other boundaries were used to partition the flood plain into spatial subsets for analysis. The GIS allowed comparisons between historical and present conditions for a variety of environmental factors. Much of the pre‐settlement channel complexity has been removed. Total channel length in 1995 was 26% less than in 1850, with almost 58% of the river's side channels disconnected from the system. In addition, we found a 72% loss of flood‐plain forest from 1850 to 1995, since it was converted to agricultural and urban land uses. Selected river and flood‐plain variables were made available for a spatial model to prioritize potential locations for flood‐plain restoration.  相似文献   

16.
龙羊峡库区环境动态监测信息系统的建立与应用   总被引:7,自引:0,他引:7  
以黄河上游最大的水利工程--龙羊峡水库为实验区,围绕库区存在的主要环境问题的研究,应用遥感与GIS一体化的方法,研究设计了系统结构、功能及数据库的组成,并建立了可运行的龙羊峡库区环境动态监测信息系统,在系统支持下有效的实现了库区环境动态监测与应用,由于该系统较强的可操作性和适应性,其成果在高寒干旱与半干旱地区环境研究中具有推广和应用价值。  相似文献   

17.
The graphical representation and interactive manipulation of accurate three dimensional (3D) models of reality is rapidly becoming an inescapable necessity for many applications of geographical information systems (GIS). There are many problems and difficulties that must be overcome in order to facilitate such 3D models. Can accurate measurements, at sufficient resolution and using affordable resources, be obtained? Will application software usefully process, in all aspects, models of the real world, held in full 3D? Can a topology of containment, adjacency and contiguity in 3D be integrated into the conventional procedural and recording functionality of two dimensional (2D) GIS and still provide workable spatial analysis tools? A 3D GIS applied to an urban environment should maintain a model that would typically consist of solid representations of individual buildings, roads and utilities, providing both external and internal detail, all assigned to a suitable digital terrain model (DTM). The particular 3D application considered here addresses the need for accurate reconstruction of historical urban buildings. The creation, manipulation and exploration of such models is often referred to as “virtual heritage”. Much of this paper describes an effective methodology, called the Phoenix algorithm, requiring only a single image of an urban object, for the construction of 3D models of buildings at high resolution. The development of this algorithm is discussed and the results obtained from it are compared with those obtained using traditional 3D capture techniques. An outline of further potential GIS applications is presented.  相似文献   

18.
数码城市GIS中建筑物室外与室内三维一体化表示与漫游   总被引:7,自引:2,他引:7  
介绍了数码城市中室外与室内场景的数据管理及可视化等关键技术,对室外与室内场景进行了综合比较,讨论了室内外场景一体化的表示思想。  相似文献   

19.
An integration between a visual programming environment and GIS has been developed to create and run spatial models. The visual programming environment provides graphical objects to create flowchart-like models of spatial phenomena using GIS data. The integrated system is object-oriented and designed to lessen the technical burdens of GIS programming. The system capabilities are demonstrated using a hydrological model example, and the model execution speed is compared with an equivalent model implementation in a traditional raster-based modelling system.  相似文献   

20.
数字景观模型(DLM,Digital Landscape Model)和数字制图模型(DCM,Digital Cartographic Model)是GIS和地图学中的重要数据模型,二者的混合模型一直是地理信息行业研究的热点。本文基于DLM与DCM的区别,并结合国内外学者的观点,阐述了地理信息与地图一体化模型在生产实践中的重要作用。  相似文献   

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