共查询到17条相似文献，搜索用时 156 毫秒
1.
草地蝗虫发生遥感监测的一种新算法 总被引：1，自引：0，他引：1
草地蝗虫发生的遥感指标分析是建立草地蝗虫发生预报模型的基础。以Landsat-5 TM为遥感信息源，根据草地蝗虫发生的遥感机理，提出了一种基于比值的草地蝗虫发生监测的遥感新算法，即R／G=(TM4 TM7)／TM6。在青海湖地区，结合草地蝗虫发生的野外样点数据，应用此新算法以及常用的标准植被指数[归一化植被指数(NDVI)和土壤调节植被指数(SAVI)]，分别进行了此3种指标对草地蝗虫发生的差异显著性检验。结果表明，在草地蝗虫密度≥5头／m^2时，常规的标准算法(NDVI，SAVI)优于新算法(RIG)；而在草地蝗虫密度≥15头／m^2和≥25头／m^2时，RIG优于NDVI和SAVI，可用于草地蝗虫发生的遥感监测。 相似文献
2.
蝗虫遥感监测预警研究现状与展望 总被引：3，自引：0，他引：3
气候变化背景下全球蝗灾日益肆虐，为支撑虫害及时精准防控，迫切需要开展大面积蝗虫动态监测预警研究。本文从蝗虫生境遥感监测、蝗虫发生动态遥感预警，以及蝗灾遥感损失评估3个方面介绍了当前研究现状，并指出当前存在的问题主要包括3个方面：蝗虫监测预警的时空分辨率较粗，无法精准定位虫害热点发生区和重点危害区；遥感虫害响应机制与虫害生物学扩散模型耦合度较低，导致模型时空普适性较差；缺乏高时空精度的虫害监测预警空间信息服务产品。因此，当前急需发展面向全球、洲际、全国、区域的多尺度、长时序、高精度虫害精准监测预警平台。通过建立时空精细尺度的虫害监测预警指标体系，研制遥感机制与虫害生物学机理深度耦合的高精度预测预报模型，发布多尺度高时频的虫害监测预警空间信息产品和服务，以实现海量数据的自动入库和智能存储、多层次模型的快速调用和高性能计算、虫害测报产品的在线生产和可视化服务。建立从数据到模型到产品服务的全链路，从而切实提升全球应对重大迁飞性虫害的智能化水平，为保障粮食安全、维护区域稳定和可持续发展提供科技支撑。 相似文献
3.
2020年初非洲东北和印巴边境沙漠蝗群席卷多个国家,大面积农田及自然植被被啃食,是什么气候条件促成了此次沙漠蝗灾?距离中国最近的印巴边境蝗群成为研究以及社会关注的热点,蝗灾对当地植被的影响如何?其发展趋势如何?从气候学上分析,蝗灾历史上是否曾经或者未来是否向印度东边迁飞而进入中国呢?本研究利用长时间序列的卫星遥感数据和气象气候观测数据,对沙漠蝗群可能扩展趋势进行了分析。研究结果表明:(1)由于沙漠蝗群的啃食,2020年1月和2月,在蝗群分布区大面积植被区的归一化植被指数较常年大幅度下降,2月(2月3日数据)的啃食面积较1月明显扩大;(2)发生在2018年5月和10月两次印度洋飓风和2019年12月强热带风暴等几个罕见气旋给非洲和阿拉伯半岛带来的强降水,是本次非洲-西亚蝗灾的形成重要原因;(3)从影响沙漠蝗群起飞的气温和沙漠蝗虫适合的降水条件来看,历史上或未来沙漠蝗群迁徙到印度东边的机会很少,进入中国的可能性非常小。 相似文献
4.
遥感与GIS在蝗虫监测和预报中的应用前景 总被引：8，自引：0，他引：8
蝗灾是世界上重要自然灾害之一 ,蝗虫监测与预报因此成为各国管理部门的重要工作内容。新兴的遥感与GIS技术由于其在空间定位、信息获取、信息处理等方面的优势 ,必将成为该领域的重要研究手段。文中回顾和总结了国内外研究者利用遥感和GIS进行蝗虫监测和预报等方面的研究进展 ,并对其技术路线、发展趋势及存在问题进行了初步探讨 相似文献
5.
蝗灾是世界上重要自然灾害之一,蝗虫监测与预报因此成为各国管理部门的重要工作内容.新兴的遥感与GIS技术由于其在空间定位、信息获取、信息处理等方面的优势,必将成为该领域的重要研究手段.文中回顾和总结了国内外研究者利用遥感和GIS进行蝗虫监测和预报等方面的研究进展,并对其技术路线、发展趋势及存在问题进行了初步探讨. 相似文献
6.
GIS辅助下的环青海湖地区草地蝗虫生境分类研究 总被引：16，自引：1，他引：16
草地蝗虫是危害中国广大草原地区的主要昆虫之一,针对草地蝗虫的生态特征,实现草地蝗虫生境类型的划分,是草地蝗灾管理迫切需要解决的课题之一.以环青海湖地区为例,使用TM影像数据和DEM,草地类型图等地理辅助数据,以及GPS定位的野外调查资料,从遥感图像处理/地理数据/专家知识一体化的角度出发,应用基于知识的方法进行环青海湖地区草地蝗虫生境类型的分类研究,其分类总精度为84.23%.研究表明,克氏针茅草原,芨芨草草原,紫花针茅草源是草地蝗虫多发的生境类型.占整个研究区总面积的29.09%,这为进一步加强环青海湖地区草地蝗虫的管理提供科学依据. 相似文献
7.
基于东亚飞蝗生育周期的遥感蝗灾监测新模式 总被引：6，自引：1，他引：6
当前 ,国际遥感蝗灾监测的技术路线一般是爆发蝗灾后受损面积、程度的监测与评价 ,研究灾害的有效预警与预测方法 ,对防灾减灾更具有现实意义。通过连续 2 0 0 1、2 0 0 2年连续实地对渤海湾夏蝗孵化期、生长期和成虫期等 7个阶段的野外观测 ,对蝗虫生境物理和生物依赖条件样方统计、光谱测试和遥感机理实验 ,提出了“飞蝗生育周期遥感三段监测”的论点 ,根据这个论点将遥感监测设计为 3个阶段 :(1 )孵化期水热条件遥感反演 ;(2 )生长期食量猛增遥感监测芦苇叶面积指数和植被盖度变化 ;(3)成虫期寻找新食源对芦苇盖度 (温度 )和地表水条件 ,进而对聚集条件和迁移方向的分析指导灭蝗。有效发挥了遥感连续动态观测的技术特点 ,为建立环渤海湾东亚飞蝗遥感监测体系提供了基本技术路线 ,介绍的思路与方法也可以对森林病虫害等大规模突发病虫灾害起到借鉴作用 相似文献
8.
岷江上游典型流域植被覆盖度的遥感模型及反演 总被引：2，自引：0，他引：2
本文在对岷江上游典型流域研究区实地踏勘和定位观测的基础上,综合利用Aster和ETM遥感数据、地面实测数据和常规观测数据等资料,研究了植被指数与植被覆盖度之间的相关性,确定了岷江上游典型流域植被覆盖度模型。以遥感图像中单个像元作为测算单位,对植被指数NDVI进行了计算,并对岷江上游毛儿盖地区植被覆盖度进行了反演。利用研究区实测数据、生态环境本底遥感调查数据和水文气象数据,对上述模型反演结果进行验证和精度分析。结果表明,模型反演结果精度较高,能较真实的反应研究区植被覆盖度实际状况。 相似文献
9.
主要研究了基于Landsat 8遥感数据的泰山地区植被指数与地形因子之间的关系。基于Landsat 8 OLI遥感数据,综合运用遥感图像处理技术和地理信息系统空间分析技术,提取泰山地区2014年7月的归一化植被指数;再利用数字高程模型(DEM)提取该地区的地形因子(海拔、坡度以及坡向);进而使用叠合分析法,分析了泰山地区植被指数与地形因子之间的关系。研究结果表明:泰山地区总体上植被指数(NDVI)值较好;植被指数随海拔的升高而增加;坡向对NDVI值影响明显,东北坡植被指数最高。数据分析的结果对于泰山地区生态环境的监测保护与可持续发展都有积极意义。 相似文献
10.
基于电磁感应的干旱区土壤盐渍化定量遥感研究 总被引：1，自引：0，他引：1
以南疆典型干旱区Landsat 7 ETM+遥感图像为数据源,利用决策树分类法提取农业用地,并对农业用地进行移动式电磁感应调查(简称磁感调查)和光谱特征提取,同时分析磁感数据和图像光谱特征与土壤盐分含量的相关性,从而建立土壤盐分的定量反演模型。研究结果表明:土地利用类型决策树的分类精度达到93.75%,Kappa系数达0.915 4;经多元逐步回归分析,磁感调查获得的土壤盐分含量与差值植被指数(DVI)、ETM+图像第二波段像元值(B2)以及比值植被指数(RVI)间具有显著相关性,由此建立的遥感反演模型可用于土壤盐分含量的定量反演。经89个样点检验,基于磁感调查的土壤盐分遥感反演精度虽低于基于磁感调查的地统计空间分析的精度,但遥感定量反演值与磁感调查实测值仍具有良好的相关性,而且精度较高,因此利用本文方法进行土壤盐渍化大面积监测是快速有效的途径。 相似文献
11.
Zhenbo Liu Xuezheng Shi Eric Warner Yunjian Ge Dongsheng Yu Shaoxiang Ni Hongjie Wang 《International Journal of Applied Earth Observation and Geoinformation》2008
Locust plagues have been the source of some of the most severe natural disasters in human history. Soil moisture content is among the most important of the numerous factors influencing plague onset and severity. This paper describes a study initiated in three pilot locust plague monitoring regions, i.e., Huangzao, Yangguanzhuang, and Tengnan in Huanghua county, Hebei province, China, to examine the impact of soil moisture status on oriental migratory locust [Locusta migratoria manilensis (L.) Meyen] plague breakout as related to the life cycle, oviposition in autumn, survival in winter, and incubation in summer. Thirty-nine temperature vegetation dryness index (TVDI) data sets, which represent soil moisture content, were extracted from MODIS remote sensing images for two representative time periods: a severe locust plague breakout year (2001–2002) and a slight plague year (2003–2004). TVDI values demonstrated distinctive soil moisture status differences between the 2 years concerned. Soil moisture conditions in the severe plague year were shown to be lower than those in slight plague year. In all three pilot regions, average TVDI value in the severe plague year was 0.07 higher than that in slight plague year, and monthly TVDI values in locust oviposition period (September and October) and incubation period (March, April and May) were higher than their corresponding monthly figures in slight plague year. No remarkable TVDI differences were found in other months during the locust life cycle between the 2 years. TVDI values for September and October (2001), March, April and May (2002) were 0.11, 0.08, 0.16, 0.11 and 0.16 higher than their corresponding monthly figures in 2003–2004 period, respectively. 相似文献
12.
Kim P. Bryceson 《国际地球制图》2013,28(4):21-37
A retrospective investigation was undertaken of the area around Broken Hill in the Western region of New South Wales, where Australian plague locust (Chortoicetes terminifera) nymphal band control took place during September ‐ November (spring) of 1987. Processed Landsat‐5 multispectralscanner data for March 1987 (autumn) were used to locate the likely spring/summer locust infestation areas using habitat type, condition and soil type as the delineating parameters. The results show that a vegetation index (indicating the degree of vegetation greeness in an area) is useful for predicting where locusts are most likely to aggregate, a classification of vegetation types is needed for determining likely breeding sites, and that there is an additional relationship between soils/geology and the location of locust infestations. These results are discussed in relation to the future operational use of the techniques in the Australian Plague Locust Commission. 相似文献
13.
卫星遥感在监视地震中的可应用性 总被引：8，自引：0，他引：8
阐述了卫星遥感技术及其产品在地震监视中的可应用性。已有震例的研究结果表明 ,震中附近存在着显著的震前地表增热现象。利用 RS热红外卫星遥感资料地气系统射出长波辐射信息 (即 OL R值 ) ,不仅可以有效地预测未来地震发生的区域 ,还可以对地表监测项目 (如地磁、地下流体、形变等 )中资料的可靠程度作出诊断。采用卫星遥感系统与地面监视系统的“融合”,形成空间与地面相结合的多源观测信息支撑的地震监视体系 ,将有助于提高我国的震情监视和预测能力 相似文献
14.
当前的重力卫星任务除了本身特有的观测方式外，都采用了高低卫卫跟踪的观测方式。为研究高低卫卫跟踪观测系统的时变行为和获取重力场信息的能力，文中运用描述时变系统的状态空间模型方法，根据附加参数的类型，建立了3种状态空间模型，并对系统的可观测性从解析法的角度进行了分析。结果表明，对于单一的高低卫卫跟踪观测系统，引力系数的可观测性实际上是不成立的，根据一次任务只能建立引力系数的一组约束条件。 相似文献
15.
Plague is a zoonotic infectious disease present in great gerbil populations in Kazakhstan. Infectious disease dynamics are influenced by the spatial distribution of the carriers (hosts) of the disease. The great gerbil, the main host in our study area, lives in burrows, which can be recognized on high resolution satellite imagery. In this study, using earth observation data at various spatial scales, we map the spatial distribution of burrows in a semi-desert landscape.The study area consists of various landscape types. To evaluate whether identification of burrows by classification is possible in these landscape types, the study area was subdivided into eight landscape units, on the basis of Landsat 7 ETM+ derived Tasselled Cap Greenness and Brightness, and SRTM derived standard deviation in elevation.In the field, 904 burrows were mapped. Using two segmented 2.5 m resolution SPOT-5 XS satellite scenes, reference object sets were created. Random Forests were built for both SPOT scenes and used to classify the images. Additionally, a stratified classification was carried out, by building separate Random Forests per landscape unit.Burrows were successfully classified in all landscape units. In the ‘steppe on floodplain’ areas, classification worked best: producer's and user's accuracy in those areas reached 88% and 100%, respectively. In the ‘floodplain’ areas with a more heterogeneous vegetation cover, classification worked least well; there, accuracies were 86 and 58% respectively. Stratified classification improved the results in all landscape units where comparison was possible (four), increasing kappa coefficients by 13, 10, 9 and 1%, respectively.In this study, an innovative stratification method using high- and medium resolution imagery was applied in order to map host distribution on a large spatial scale. The burrow maps we developed will help to detect changes in the distribution of great gerbil populations and, moreover, serve as a unique empirical data set which can be used as input for epidemiological plague models. This is an important step in understanding the dynamics of plague. 相似文献
16.
Small satellites for global coverage: Potential and limits 总被引：2，自引：0，他引：2
Rainer Sandau Klaus Brieß Marco D&#x;Errico 《ISPRS Journal of Photogrammetry and Remote Sensing》2010,65(6):492-504
There is an increasing need for Earth Observation (EO) missions to meet the information requirements in connection with Global Change Studies. Small and cost-effective missions are powerful tools to flexibly react to information requirements with space-borne solutions. Small satellite missions can be conducted relatively quickly and inexpensively by using commercial off-the-shelf-technologies, or they can be enhanced by using advanced technologies. A new class of advanced small satellites, including autonomously operating “intelligent” satellites may be created, opening new fields of application. The increasing number of small satellites and their applications drive developments in the fields of small launchers, small ground station networks, cost-effective data distribution methods, and cost-effective management and quality assurance procedures. There are many advantages of small satellite missions, like more frequent mission opportunities, a faster return of data, larger variety of missions, more rapid expansion of the technical and/or scientific knowledge base, greater involvement of small industry, feasibility by universities and others.This paper deals with general trends in the field of small satellite missions for Earth observation. Special attention is given to the potential of spatial, spectral, and temporal resolution of small satellite based systems. Examples show small satellites offer also the unique possibility to install affordable constellations to provide good daily coverage of the globe and/or allow us to observe dynamic phenomena.The facts and examples given in this paper lead to the conclusion: Small satellites are already powerful tools for monitoring global, regional and local phenomena. In the future, their application spectrum will even broaden based on the ongoing development in many areas of technology and observation techniques. 相似文献
17.
21世纪以来,高分辨率对地观测卫星快速发展,对地观测系统由最初的单星模式发展为现在的轻小型卫星组建星座,实现了全天时、全天候、全方位的对地精细化观测。未来将对地观测卫星星座与通信卫星、导航卫星和飞机等空间节点通过动态组网,建立天基空间信息网络,以实现智能化空天信息的实时服务。为了进一步增强系统的智能化水平,提高系统感知、认知能力和应急响应能力,本文提出未来空间信息网络环境下对地观测脑（earth observation brain,EOB）的概念,对地观测脑是基于事件感知的智能化对地观测系统。详细介绍了对地观测脑的概念模型及需要解决的关键技术,举例说明了对地观测脑初级阶段的感知、认知过程。将来对地观测脑可以回答何时（when）、何地（where）、何目标（what object）发生了何种变化（what change）,并在规定的时间（right time）和地点（right place）把这些正确的信息（right information）推送给需要的人（right people）的手机或其他智能终端,全球用户可实时获得所需的任何数据、信息和知识。 相似文献