A Multiscale Object-Specific Approach to Digital Change Detection   总被引：1，自引：0，他引：1  

Ola Hall  Geoffrey J. Hay 《International Journal of Applied Earth Observation and Geoinformation》2003,4(4):311-327

Landscape spatial pattern is dependent not only on interacting physiographic and physiological processes, but also on the temporal and spatial scales at which the resulting patterns are assessed. To detect significant spatial changes occurring through space and time three fundamental components are required. First, a multiscale dataset must be generated. Second, a change detection framework must be applied to the multiscale dataset. Third, a procedure must be developed to delineate individual image-objects and identify them as they change through scale. In this paper, we introduce an object-specific multiscale digital change detection approach. This approach incorporates multitemporal SPOT Panchromatic (Pan) data, object-specific analysis (OSA), object-specific up-scaling (OSU), marker-controlled watershed segmentation (MCS) and image differencing change detection. By applying this framework to SPOT Pan data, image-objects that have changed between registration dates can be identified and delineated at their characteristic scale of expression. Results illustrate that this approach has the ability to automatically detect changes at multiple scales as well as suppress sensor related noise. This study was conducted in the forest region of the Örebro Administrative Province, Sweden.  相似文献   

Flood delineation in a large and complex alluvial valley, lower Pa´nuco basin, Mexico     

Paul F. Hudson  Ren R. Colditz 《Journal of Hydrology》2003,280(1-4):229-245

Determining the extent of flooding is an important role of the hydrological research community and provides a vital service to planners and engineers. For large river systems located within distant settings it is practical to utilize a remote sensing approach. This study combines a remote sensing and geomorphic approach to delineate the extent of a large hurricane generated flood event in the lower Pánuco basin (98,227 km²), the seventh largest river system draining into the Gulf of Mexico. The lower Pánuco basin is located within the coastal plain of eastern Mexico and has a complex alluvial valley. Data sources included a Landsat 5TM and Landsat 7ETM⁺ scene, and topographic and particle size data from fieldwork and laboratory analysis. The Landsat 5TM image was acquired after the peak of a large flood event in 1993, whereas the Landsat 7ETM⁺ scene was acquired during the dry season in 2000. The increasing number of days between flood crest and the date of flood image acquisition along the river valley provided the opportunity to examine several methods of flood delineation and to consider differences in floodplain geomorphology. Backswamp environments were easily delineated in flooded reaches within the Panuco and Tamuin valleys, whereas in the Moctezuma valley more sophisticated methods were required because of the greater time between image acquisition and flood peak, and the complex floodplain topography. This included Principal Component (PC) analysis and image classification. Within the floodplain, residual Holocene terraces complicated flood mapping. Classification of both images allowed consideration of the influence of permanent standing water. Although the flooded areas were greater in the lower reaches of the study area, because this portion of the valley contained large floodplain lakes, the amount of inundation was actually lower. Remote sensing offers the ability to examine large alluvial valleys in distant settings but does not imply that geomorphic criteria should be excluded. Indeed, because of heterogeneous floodplain topography this study illustrates the importance of including field based geomorphic analysis so that the complexity of distinct floodplain environments are considered. The findings from this study are significant because most remote sensing data obtained for the purpose of flood mapping will not coincide with the flood crest. Thus, this study provides an appropriate method for mapping flood inundation in large and complex floodplain settings after flood crest recession.  相似文献   

Mapping of Land-Atmosphere Heat Fluxes and Surface Parameters with Remote Sensing Data   总被引：3，自引：0，他引：3  

Francesca Caparrini  Fabio Castelli  Dara Entekhabi 《Boundary-Layer Meteorology》2003,107(3):605-633

A variational data assimilation scheme is used to infer two key parameters ofthe surface energy balance that control the partitioning of available energy intolatent, sensible, and ground heat fluxes (LE, H, and G). Remotely sensedland surface temperature (LST) is the principal data source. Maps ofdiurnal energy balance components are presented for a basin with varied landcover (Arno Basin, Italy) for a 18-day period in July 1996.Given available energy, the major unknown (dimensionless) parameters requiredfor partitioning among fluxes are: (1) Landscape effects on near-surfaceturbulence as captured by the bulk heat transfer coefficient C_BN underneutral conditions and (2) surface control of the relative magnitudes of LEand H as represented by the evaporative fraction E_F. The data assimilationscheme merges 1.1-km resolution remotely sensed LST images (based onoptical, thermal and microwave measurements from two different satelliteplatforms) into a parsimonious model of heat diffusion. Both the measurementsand the model predictions are considered uncertain. Posterior error statisticsthat represent uncertainty of the estimated parameters are also derived.Maps of C_BN show spatial patterns consistent with the dominant land useand basin physiography. Daily maps of E_F exhibit spatial variationscorresponding to land cover and land use – the day-to-day variations inE_F show fluctuations consistent with rain events and drydowns experiencedduring the period. Based on these parameters and available environmentalvariables, maps of diurnal LE and H may be produced (in this paper daytimeLE maps are reported).The application demonstrates that remotely sensed land surface temperaturesequences contain significant amount of information of the partitioning ofavailable energy among the fluxes. The variational data assimilation frameworkis shown to be an efficient and parsimonious approach without reliance onempirical relationships such as those based on vegetation indices.  相似文献   

中国华北地区土地利用动态变化特点分析   总被引：7，自引：3，他引：7  

赵晓丽  张增祥  邹亚荣  周全斌 《国土资源遥感》2002,(2):23-28

以遥感与GIS为技术支撑，对华北地区1995－2000年土地利用动态变化进行了调查，并对变化特点进行了分析。结果表明，华北地区城乡、农村居民点及工交建设用地增加显，以农村居民点的变化尤为突出；耕地减少，且主要变为建设用地；林地减少；未利用土地面积减少明显；土地利用类型多样性在降低，说明人类活动进一步加剧，对生态环境造成不良影响。  相似文献   

江苏海岸线演变趋势遥感分析   总被引：16，自引：4，他引：16  

蔡则健  吴曙亮 《国土资源遥感》2002,13(3):19-23

数千年来,海岸线的摆动使江苏省东部经历了“沧海桑田”的变化,海岸线的进退都会给沿海人们的生存和发展带来直接影响。作者利用3期卫星遥感图像资料对江苏海岸线20a来的演变特点和趋势作了定量和定性的分析。根据史料,对历史岸线作了概略地分析,同时对岸线的稳定性进行了划分。  相似文献   

西部遥感发展现状与前景展望   总被引：3，自引：0，他引：3  

伍跃中  谭克龙  马贺平 《国土资源遥感》2002,13(4):1-6

西部遥感经过20多年的发展,已经形成了航天、航空、地面探测以及与GIS相结合的较完善的遥感技术应用研究体系,是西部地区资源、环境、灾害调查与监测的重要技术支撑。本文首先回顾了西部遥感技术应用试验研究,总结了西部遥感在各领域的应用现状并择要列举了部分成果,最后结合西部大开发的需求,阐述了西部遥感今后发展前景与对策。  相似文献   

赣中红壤区TM图像的居民地信息自动提取专家模式研究   总被引：12，自引：1，他引：12  

高永光  祝民强  朱骥  刘帅 《国土资源遥感》2002,13(4):67-69

从遥感信息分析入手,分析了抚州地区居民地在Landsat TM1 TM2 TM3 TM4 TM5 TM6 TM7各个波段上与其它背景地物的可分性。通过对各地物光谱曲线特征进行分析,利用居民地光谱特征与其它地物的差异性,建立条件表达式,即可把该区的居民地提取出来。通过验证,其点位精度达到81%,面积精度达到75%。该研究表明,通过简单模型的建立,可将以水泥顶房屋和瓦顶房屋为主的居民地提取出来。  相似文献   

青藏高原地表月平均反照率的遥感反演   总被引：21，自引：9，他引：21  

徐兴奎  林朝晖 《高原气象》2002,21(3):233-237

位于我国西南部的青藏高原是世界上海拔最高，地形最复杂的高原，其热力和动力作用对我国和全球气候系统的影响非常显著，而高原地表反照率是决定地表能量收支平衡十分重要的参数。本文采用卫星遥感和地理信息系统技术，应用目前国际上最先进的双向反射模型，建立了动态的地表反照率反演方法，并对1997年青藏高原地表反照率进行了反演。  相似文献   

地质灾害遥感调查的应用前景   总被引：15，自引：0，他引：15  

冯东霞余德清  龙解冰 《湖南地质》2002,21(4):314-318

地质灾害遥感调查正由示范性实验阶段步入全面推广的实用性阶段。遥感技术及与之相关的高新技术的飞速发展，已使地质灾害遥感调查成为可能。遥感技术可以贯穿于地质灾害调查、监测、预警、评估的全过程，能适应突发性地质灾害救灾工作的时效性要求，因而具有广阔的应用前景。  相似文献   

西藏定结幅区调工作中的断裂构造遥感研究方法探讨   总被引：1，自引：0，他引：1  

隋志龙  杨巍然  张利华 《大地构造与成矿学》2002,26(4):452-458

西藏定结地区地质构造背景复杂、型式多样,对包括变质核杂岩在内的断裂构造的研究是该地区构造解析的重点内容。在该地区有效地运用遥感技术来辅助野外实地调查十分必要。本文从信息提取、光谱特征分析、空间结构分析等几个方面探讨了在该地区运用遥感技术进行断裂构造研究的工作方法。另外,针对定结幅ETM+影像的实际情况,分别介绍了冰雪覆盖下的地物弱信息提取和高山地区地形影响的消除及三维信息恢复等图像处理方法。  相似文献