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Apparent reciprocity failure in directional reflectance of structured surfaces

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Progress in Natural Science:Materials International 1999年第10期9卷 28-33页

作者：李小文,王锦地,Alan H.STRAHLER Research center for remote sensing Beijing Normal University Beijing 100875 China center for remote sensing and department of geography Boston University MA 02215 USA Research center for remote sensing Beijing Normal University Beijing 100875 China center for remote sensing and department of geography Boston University MA 02215 USA

Whether the reciprocity principle can be applied to the field or satellite observations of directional reflectance of land surface has been a question important to both theory and practice of land surface remote sensing. Under the assumption that every point on ground follows reciprocity, this paper explains why the heterogeneity of land surface can still yield apparent failure of the principle at the scale of remote sensing pixel.

关键词： reciprocity structure BRDF

Seismic vulnerability assessment of urban buildings and traffic networks using fuzzy ordered weighted average

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Journal of Mountain Science 2019年第3期16卷 677-688页

作者： Yasaman ASADI Najmeh Neysani SAMANY Keyvan EZIMAND department of remote sensing and GIS Faculty of GeographyUniversity of Tehran remote sensing and GIS center Faculty of Earth ScienceUniversity of Shahid Beheshti

Urban buildings and urban traffic network are considered as the vital arteries of cities which have particular effects especially after the crisis in the search and rescue operations. The aim of this study is to determine the vulnerability of urban areas especially, buildings and traffic networks using multicriteria geographic information systems and decisionmaking methods. As there are many effective criteria on the seismic vulnerability that they have uncertain and vague properties, the method of this paper is applying fuzzy ordered weighted average(OWA) to model the seismic vulnerability of urban buildings and traffic networks in the most optimistic and pessimistic states. The study area is district 6 of Tehran that is affected by the four major faults, and thus will be threatened by the earthquakes. The achieved results illustrated the vulnerability with different degrees of risk levels including very high, high, medium, low and very low. The results show that in the most optimistic case 14% and in the pessimistic case 1% of buildings tolerate in very low vulnerability. The vulnerability of urban street network also indicates that in the optimistic case 12% and in the pessimistic case at most 9% of the area are in appropriate condition and the North and NorthEast of the study area are more vulnerable than South of it.

关键词： Earthquake Vulnerability Assessment Urban buildings Traffic network Multi-Criteria Decision Analysis(MCDA) Fuzzy-OWA

Research on scale effect of histogram

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Science China Earth Sciences 2002年第10期45卷 949-960页

作者：张颢李小文阎广建焦子锑王锦地赵红蕊杨华苏理宏 1. Research center for remote sensing and GIS Department of Geography and Beijing Key Laboratory for Remote Sensing of Environment and Digital Cities Beijing Normal University 100875 Beijing China 2. center for remote sensing and department of geography Boston University 02215 MA USA

To describe the spatial relationship among the earth objects compactly, in this paper, we raised the concept of histo-variogram based on the analysis of the characteristics of other spatial analyzing methods such as variogram, information entropy. And we also raised a new spatial analysis method of histogram decomposition based on the definition of standing pixel and contour pixel. At the end of this paper, we demonstrated the characteristics of histo-variogram by two experiments, one for spatial analysis, the other for image fusion.

关键词： histo-variogram, scaling, histogram-decomposition, standing-pixel, HIS transform.

Thermal bidirectional gap probability model for row crop canopies and validation

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Science China Earth Sciences 2003年第12期46卷 1241-1249页

作者：阎广建蒋玲梅王锦地陈良富李小文 Research center for remote sensing and GIS Department of Geography and Beijing Key Laboratory for Remote Sensing of Environment and Digital Cities Beijing Normal University Beijing 100875 China LARSIS Institute of Remote Sensing Application Chinese Academy of Sciences Beijing 100101 China department of geography and center for remote sensing Boston University Boston MA 02215 USA

Based on the row structure model of Kimes and the mean gap probability model in single direction, we develop a bidirectional gap probability model for row crop canopies. A concept of overlap index is introduced in this model to consider the gaps and their correlation between the sun and view directions. Multiangular thermal emission data sets were measured in Shunyi, Beijing, and these data are used in model validation in this paper. By comparison with the Kimes model that does not consider the gap probability, and the model considering the gap in view direction only, it is found that our bidirectional gap probability model fits the field measurements over winter wheat much better.

关键词： row crop, bidirectional gap probability, thermal emission, hot spot effect.

Spatial Pattern Evolution and Casual Analysis of County Level Economy in Changsha-Zhuzhou-Xiangtan Urban Agglomeration, China

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Chinese Geographical Science 2014年第5期24卷 620-630页

作者： DONG Minghui ZOU Bin PU Qiang WAN Neng YANG Lingbin LUO Yanqing department of geography Hunan University of Arts and Science department of Geomatics and remote sensing Central South University department of geography University of Utah department of geography Northeast Normal University

In order to evaluate whether or not the county units′ economy in the Changsha-Zhuzhou-Xiangtan(Chang-Zhu-Tan) Urban Agglomeration was growing as expected, this study analyzed the spatial economy pattern at county-level by using the Exploratory Spatial Data Analysis(ESDA) method. In this process, the global Moran′s I and local Getis-Ord G*i indexes were employed to analyze indicators including per capita GDP and three industrials(i.e. primary, secondary and tertiary industry) from 2000 to 2010. The results show that: 1) the county units′ economy in the Chang-Zhu-Tan Urban Agglomeration has exhibited a strong spatial autocorrelation and an accelerated integration trend since 2008(Moran′ s I increased from 0.26 to 0.56); 2) there is a significant difference in economy development between the northern and southern county units in the Chang-Zhu-Tan Urban Agglomeration: the hotspot zone with high economic level was formed among the northern county units whereas the coldspot zone with low economic level was located in the southern areas. This difference was caused primarily by the increasingly prominent economic radiation effect of Changsha ′upheaval′; 3) town density, secondary industry, and the integration policy are the major contributors driving the evolution of the spatial economy pattern in the Chang-Zhu-Tan Urban Agglomeration.

关键词： spatial autocorrelation spatial heterogeneity urban agglomeration county-level economy Changsha-Zhuzhou-Xiangtan (Chang-Zhu-Tan), China

Seismic vulnerability assessment of urban buildings using the rough set theory and weighted linear combination

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Journal of Mountain Science 2022年第3期19卷 849-861页

作者： Yasaman ASADI Najmeh NEYSANI SAMANY Majid KIAVARZ MOQADAM Ata ABDOLLAHI KAKROODI Meysam ARGANY department of remote sensing and GIS Faculty of GeographyUniversity TehranTehran 33137-67464Iran

Seismic vulnerability assessment of urban buildings is among the most crucial procedures to post-disaster response and recovery of infrastructure *** present study proceeds to estimate the seismic vulnerability of urban buildings and proposes a new framework training on the two ***,a comprehensive interpretation of the effective parameters of this phenomenon including physical and human factors is ***,the Rough Set theory is used to reduce the integration uncertainties,as there are numerous quantitative and qualitative *** objectives were conducted on seven distinct earthquake scenarios with different intensities based on distance from the fault line and the *** proposed method was implemented by measuring seismic vulnerability for the seven specified seismic *** final results indicated that among the entire studied buildings,71.5%were highly vulnerable as concerning the highest earthquake scenario(intensity=7 MM and acceleration calculated based on the epicenter),while in the lowest earthquake scenario(intensity=5 MM),the percentage of vulnerable buildings decreased to approximately 57%.Also,the findings proved that the distance from the fault line rather than the earthquake center(epicenter)has a significant effect on the seismic vulnerability of urban *** model was evaluated by comparing the results with the weighted linear combination(WLC)*** accuracy of the proposed model was substantiated according to evaluation *** assessment based on the distance from the epicenter and its comparison with the distance from the fault shows significant reliable results.

关键词： Seismic vulnerability Urban buildings Rough set theory Earthquake scenarios WLC

Improvement on the inversion of kernel-driven BRDF model

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Chinese Science Bulletin 1999年第1期44卷 76-79页

作者： Alan H.Strahler department of geography and Centre for remote sensing Boston University Boston USA

Kernel-driven model was chosen to calculate global albedo in the project of multiangular remote sensor MODIS. The best kernels were selected by the venerable 'least square' method. The result of this method was very unstable when only a small amount of angular observations is available. A new criterion has been estalished, called 'least variance' for the kernel’s selection. It takes into consideration the effects of model and measurement based on the information inverse theory. Several tests showed that 'least variance' has many advantages. First, it is less sensitive to noises. Second, it operates well in small sample size. Third, it depends less on the sampling position.

关键词： multiangular remote sensing BRDF model inversion global albedo.

Vegetation physiological parameter setting in the Simple Biosphere model 2(SiB2) for alpine meadows in the upper reaches of Heihe river

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Science China Earth Sciences 2015年第5期58卷 755-769页

作者： LI Yuan SUN Rui LIU Shao Min State Key Laboratory of remote sensing Science Beijing Normal University and Institute of Remote Sensing and Digital Earth CAS School of geography Beijing Normal University Beijing Key Laboratory of Environmental remote sensing and City Digitalization department of Civil Engineering Monash University

Land surface process modeling of high and cold area with vegetation cover has not yielded satisfactory results in previous applications. In this study, land surface energy budget is simulated using a land surface model for the A'rou meadow in the upper-reach area of the Heihe River Basin in the eastern Tibetan Plateau. The model performance is evaluated using the in-situ observations and remotely sensed data. Sensible and soil heat fluxes are overestimated while latent heat flux is underestimated when the default parameter setting is used. By analyzing physical and physiological processes and the sensitivities of key parameters, the inappropriate default setting of optimum growth and inhibition temperatures is identified as an important reason for the bias. The average daytime temperature during the period of fastest vegetation growth(June and July) is adopted as the optimum growth temperature, and the inhibition temperatures were adjusted using the same increment as the optimum temperature based on the temperature acclimation. These adjustments significantly reduced the biases in sensible, latent, and soil heat fluxes.

关键词： SiB2 land surface process alpine meadow Heihe River Basin Tibetan Plateau

F4ESS-a framework for interdisciplinary data-driven earth system science

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International Journal of Digital Earth 2023年第1期16卷 3973-3986页

作者： Doris Dransch Daniel Eggert Mike Sips remote sensing and Geoinformatics Helmholtz Center Potsdam–German Research Center for GeosciencePotsdamGermany geography department Humboldt-University at BerlinBerlinGermany

Earth system science is an interdisciplinary effort to understand the fundamentals and interactions of environmental *** research is challenging since it demands the integration of scientific schemes and practices from different research fields into a collaborative work *** paper introduces the framework F4ESS that supports this integration.F4ESS provides methods and technologies that facilitate the development of integrative work environments for Earth system science.F4ESS enables scientists a)to outline structured and summarized descriptions of scientific procedures to facilitate communication and synthesis,b)to combine a large variety of distributed data analysis software into seamless data analysis chains and workflows,c)to visually combine and interactively explore the manifold spatiotemporal data and results to support understanding and knowledge *** F4ESS methods and technologies are generic and can be applied in various scientific *** discuss F4EsS in the context of the interdisciplinary investigation of flood events.

关键词： Earth system science interdisciplinary research scientific workflows integration