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Mapping paddy rice with multi-date moderate-resolution imaging spectroradiometer (MODIS) data in China

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Journal of zhejiang university-Science A(Applied Physics & Engineering) 2009年第10期10卷 1509-1522页

作者： Hua-sheng SUN Jing-feng HUANG Alfredo R. HUETE Dai-liang PENG Feng ZHANG institute of agricultural remote sensing and lnformation application Zhejiang University Hangzhou 310029 China Key Lab of agricultural remote sensing and lnformation System Hangzhou 310029 China MOE Key Lab of Environmental Remediation and Ecological Health Zhejiang University Hangzhou 310029 China Department of Soil Water and Environmental Science University of Arizona Tucson AZ85721 USA Resources and Environment Department Xinjiang Agricultural University Urumchi 830052 China College of Surveying and Mapping Xuzhou Normal University Xuzhou 221116 China

The objective of this study was to obtain spatial distribution maps of paddy rice fields using multi-date moderate-resolution imaging spectroradiometer(MODIS) data in *** rice fields were extracted by identifying the unique char-acteristic of high soil moisture in the flooding and transplanting period with improved algorithms based on rice growth calendar *** characteristic could be reflected by the enhanced vegetation index(EVI) and the land surface water index(LSWI) derived from MODIS sensor *** for single,early,and late rice identification were obtained from selected typical test *** algorithms could not only separate early rice and late rice planted in the same fields,but also reduce the *** areal accuracy of the MODIS-derived results was validated by comparison with agricultural statistics,and the spatial matching was examined by ETM+(enhanced thematic mapper plus) images in a test *** factors that might cause errors,such as the coarse spatial resolution and noises in the MODIS data,were *** not suitable for monitoring the inter-annual variations due to some inevitable factors,the MODIS-derived results were useful for obtaining spatial distribution maps of paddy rice on a large scale,and they might provide reference for further studies.

关键词： remote sensing Moderate-resolution imaging spectroradiometer (MODIS) Enhanced vegetation index (EVI) Land surface water index (LSWI) Paddy rice China

Monitoring rapid urban expansion using a multi-temporal RGB-impervious surface model

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Journal of zhejiang university-Science A(Applied Physics & Engineering) 2012年第2期13卷 146-158页

作者： Amirreza SHAHTAHMASSEBI Zhou-lu YU Ke WANG Hong-wei XU Jin-song DENG Jia-dan LI Rui-sen LUO Jing WU Nathan MOORE institute of Agriculture remote sensing and information Technology Zhejiang UniversityHangzhou 310029China Department of Geography Michigan State UniversityM148823USA

In this paper, we developed a novel method of combining remote sensing tools at the sub-pixel level for accurate identification of impervious surface time series changes. We examined the use of the red-green-blue impervious surface model (RGB-IS) in detecting time series internal modification of urban regions by integrating Landsat data collected over four different periods between 1987 and 2009 (i.e., 1987, 2000, 2002, and 2009). The performance of this approach was compared with two conventional methods, namely standard RGB-normalized difference vegetation index (NDVI) and post-classification technique. In contrast to conventional techniques, RGB-IS could monitor between-class changes, within-class changes, and location of these modifications. The proposed method was independent of seasonal changes and was also able to serve as a useful alternative for quick mapping growth hotspots and updating transportation corridor map. The results also showed that Cixi County, zhejiang Province, China experienced tremendous impervious surface changes, especially along the corridors of newly constructed highways and around urban areas over the past 22 years.

关键词： Red-green-blue impervious surface model (RGB-IS). Multi-temnoral. Imnervious surface. Landsat

NDVI-Based Lacunarity Texture for Improving Identification of Torreya Using Object-Oriented Method

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agricultural Sciences in China 2011年第9期10卷 1431-1444页

作者： HAN Ning WU Jing Amir Reza Shah Tahmassebi XU Hong-wei WANG Ke institute of remote sensing and information System application College of Environment and Resource Science Zhejiang University Hangzhou 310029 P.R. China School of Environment and Resource Zhejiang Agriculture and Forestry University Hangzhou 311300 P.R.China

Normalized Difference Vegetation Index （NDVI） is a very useful feature for differentiating vegetation and non-vegetation in remote sensed imagery. In the light of the function of NDVI and the spatial patterns of the vegetation landscapes, we proposed the lacunarity texture derived from NDVI to characterize the spatial patterns of vegetation landscapes concerning the ＂gappiness＂ or ＂emptiness＂ characteristics. The NDVI-based lacunarity texture was incorporated into object-oriented classification for improving the identification of vegetation categories, especially Torreya which was the targeted tree species in the present research. A three-level hierarchical network of image objects was defined and the proposed texture was integrated as potential sources of information in the rules base. A knowledge base of rules created by classifier C5.0 indicated that the texture could potentially be applied in object-oriented classification. It was found that the addition of such texture improved the identification of every vegetation category. The results demonstrated that the texture could characterize the spatial patterns of vegetation structures, which could be a promising approach for vegetation identification.

关键词： Torreya NDVI lacunarity class hierarchy object-oriented method decision tree spatial pattern

A semantic geographical knowledge wiki system mashed up with Google Maps

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Science China(Technological Sciences) 2010年第S1期53卷 52-60页

作者： GAO Yong,GAO Song,LI RunQiang & LIU Yuinstitute of remote sensing and Geographical information Systems,Peking university,Beijing 100871,China institute of remote sensing and Geographical information Systems Peking University Beijing China

A wiki system is a typical Web 2.0 application that provides a bi-directional platform for users to collaborate and share much useful information ***,computers cannot well understand the wiki pages in plain *** user-generated geographical content via wiki systems cannot be manipulated properly and efficiently unless the geographical semantics is explicitly *** this paper,a geographical semantic wiki system,Geo-Wiki,is introduced to solve this ***-Wiki is a semantic geographical knowledge-sharing web system based on geographical ontologies so that computers can parse and storage the multi-source geographical ***,Geo-Wiki mashed up with map services enriches the representation and helps users to find spatial distribution patterns,and thus can serve geospatial decision-making by customizing the Google Maps APIs.

关键词： geo-ontology semantic wiki mashup Google Maps

Spatiotemporal Dynamics of Urban Growth in Island Region from a Multi-scale Perspective: a Case Study of Zhoushan Island,China

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Journal of Donghua university(English Edition) 2017年第1期34卷 66-75页

作者：潘艺王阳祝锦霞王珂沈掌泉 Institution of remote sensing and information System application Zhejiang University Institution of Land and Urban Rural Development Zhejiang University of Finance&Economics

The intensified conflict between island urbanization and lagging supervision deserves special attention *** Island has been an outstanding center of marine economic development in China but also one of the areas most threatened by recent human *** cope with this challenge,the development of a retrospective understanding of the spatiotemporal dynamics of island urban growth is a key ***,multi-scales,long-term studies on island urban expansion are relatively *** sensing data,landscape metrics,and spatial statistics were used to characterize the urban landscape changes during the years from 1980 to ***,the potential determinants of island urban expansion were analyzed by integrating socioeconomic drivers,population factors,topographic variables,and policy *** results indicate that Zhoushan Island has experienced a considerable urban expansion with an evident acceleration during the last *** changes in response to urban expansion varied with time,region,and scale.A general understanding of landscape metrics failed to reveal accurate dynamics for the urban landscape at a local *** a block size of1 km,the urban landscape was more compact around the island urban center and the new developing zone,in contrast to the extensive and scattered pattern present across the entire *** land primarily expanded from the urban center to the coastal regions due to topographic constraints and support from policy and economic *** potential impact of the population factor decreased with urban growth,a finding that differs from several previous *** island urban dynamics observed in this study involved characteristics and differences that will guide future planning decisions and will provide a scientific case for urban development and sustainability with respect to islands and coastal regions in China.

关键词： urbanization landscape metrics spatial autocorrelation scale effects

First wetland mapping at 10-m spatial resolution in South America using multi-source and multi-feature remote sensing data

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Science China Earth Sciences 2024年第10期67卷 3252-3269页

作者： Weiwei SUN Gang YANG Yuling HUANG Dehua MAO Ke HUANG Lin ZHU Xiangchao MENG Tian FENG Chao CHEN Yong GE Department of Geography and Spatial information Techniques Ningbo UniversityNingbo 315211China State Key Laboratory of Resources and Environmental information System Institute of Geographic Sciences&Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Natural Resources and Planning Bureau Shanghai Pudong New DistrictShanghai 200100China Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China Faculty of Electrical Engineering and Computer Science Ningbo UniversityNingbo 315211China School of Geography Science and Geomatics Engineering Suzhou University of Science and TechnologySuzhou 215009China

Wetland degradation has been accelerating in recent years globally. Accurate information on the geographic distribution and categories of wetlands is essential for their conservation and management. Despite being the world′s fourth largest continent, South America has limited research on wetland mapping, and there is currently no available map that provides comprehensive information on wetland distribution and categories in the region. To address this issue, we used Sentinel-1, Sentinel-2 and SRTM data, developed a sample collection method and a wetland mapping method with a collection of multi-source features such as optical features, polarization features and shape features for South American wetlands. We produced a 10-m resolution wetland map based on the Google Earth Engine(GEE) platform. Our Level-1 wetland cover map accurately captured six wetland sub-categories with an overall accuracy of 96.24% and a kappa coefficient of 0.8649, while our Level-2 water cover map included five sub-categories with an overall accuracy of 97.23% and a kappa coefficient of0.9368. The results show that the total area of existing wetlands in South America is approximately 1,737,000 km~2, which is6.8% of the total land area. Among the ten wetland categories, shallow sea had the largest area(960,527.4 km~2), while aquaculture ponds had the smallest area 1513.6 km~2. Swamp had the second largest area(306,240.1 km~2). Brazil, Argentina,Venezuela, Bolivia, and Colombia were found to have the largest wetland areas, with Brazil and Colombia having the most diverse wetland categories. This product can serve as baseline data for subsequent monitoring, management, and conservation of South American wetlands.

关键词： Wetland mapping Google Earth Engine Sentinel imagery South America

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A GIS-based approach for estimating spatial distribution of seasonal temperature in zhejiang Province, China

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Journal of zhejiang university-Science A(Applied Physics & Engineering) 2006年第4期7卷 647-656页

作者： LI Jun HUANG Jing-feng WANG Xiu-zhen Department of Natural Resource Science Zhejiang University Hangzhou 310029. China institute of agricultural remote sensing ＆ information application Zhejiang University Hangzhou 310029 China zhejiang Meteorological institute Hangzhou 310004 China

This paper presents a zhejiang Province southeastern China seasonal temperature model based on GIS techniques. Terrain variables derived from the 1 km resolution DEM are used as predictors of seasonal temperature, using a regression-based approach. Variables used for modelling include: longitude, latitude, elevation, distance from the nearest coast, direction to the nearest coast, slope, aspect, and the ratio of land to sea within given radii. Seasonal temperature data, for the observation period 1971 to 2000, were obtained from 59 meteorological stations. Temperature data from 52 meteorological stations were used to construct the regression model. Data from the other 7 stations were retained for model validation. Seasonal temperature surfaces were constructed using the regression equations, and refined by kriging the residuals from the regression model and subtracting the result from the predicted surface. Latitude, elevation and distance from the sea are found to be the most important predictors of local seasonal temperature. Validation determined that regression plus kriging predicts seasonal temperature with a coefficient of determination (R2), between the estimated and observed values, of 0.757 (autumn) and 0.935 (winter). A simple regression model without kriging yields less accurate results in all seasons except for the autumn temperature.

关键词： GIS Multiple regression analysis Interpolation Seasonal temperature Spatial distribution

Estimation of rice phenology date using integrated HJ-1 CCD and Landsat-8 OLI vegetation indices time-series images

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Journal of zhejiang university-Science B(Biomedicine & Biotechnology) 2015年第10期16卷 832-844页

作者： Jing WANG Jing-feng HUANG Xiu-zhen WANG Meng-ting JIN Zhen ZHOU Qiao-ying GUO Zhe-wen ZHAO Wei-jiao HUANG Yao ZHANG Xiao-dong SONG institute of remote sensing and information application College of Environmental and Resource Sciences Zhejiang University institute of remote sensing and Earth Sciences Hangzhou Normal University

Accurate estimation of rice phenology is of critical importance for agricultural practices and studies. However, the accuracy of phenological parameters extracted by remote sensing data cannot be guaranteed because of the influence of climate, e.g. the monsoon season, and limited available remote sensing data. In this study, we integrate the data of H J-1 CCD and Landsat-8 operational land imager （OLI） by using the ordinary least-squares （OLS） and construct higher temporal resolution vegetation indices （VIs） time-series data to extract the phenological param- eters of single-cropped rice. Two widely used VIs, namely the normalized difference vegetation index （NDVI） and 2-band enhanced vegetation index （EVI2）, were adopted to minimize the influence of environmental factors and the intrinsic difference between the two sensors. Savitzky-Golay （S-G） filters were applied to construct continuous VI profiles per pixel. The results showed that, compared with NDVI, EVI2 was more stable and comparable between the two sensors. Compared with the observed phenological data of the single-cropped rice, the integrated VI time-series had a relatively low root mean square error （RMSE）, and EVI2 showed higher accuracy compared with NDVI. We also demonstrate the application of phenology extraction of the single-cropped rice in a spatial scale in the study area. While the work is of general value, it can also be extrapolated to other regions where qualified remote sensing data are the bottleneck but where complementary data are occasionally available.

关键词： Phenological parameters Intercalibration Vegetation index H J-1 CCD Landsat-80LI

High-resolution remote thermometry based on Bi^(3+)-doped 0D zinc halide hybrids

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Science China Chemistry 2024年第8期67卷 2599-2605页

作者： Cui-Mi Shi Shu-Hua Xue Jin-Yun Wang Liang-Jin Xu Zhong-Ning Chen State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian Science Technology Innovation Laboratory for Optoelectronic Information of ChinaFuzhou 350108China university of Chinese Academy of Sciences Beijing 100049China

Developing highly sensitive optical thermometers is of great significance due to their capability to enable remote and non-contact temperature measurements, rendering them highly applicable in diverse and harsh environments. Herein we report a temperature-dependent phosphor of 0D metal halide hybrid by incorporating Bi^(3+)into the(MePPh_(3))_(2)ZnCl_(4) matrix. Through Bi^(3+)doping,the initially non-luminescent(MePPh_(3))_(2) ZnCl_(4) matrix exhibits a deep-blue emission centered at 453 nm, with a photoluminescence quantum yield(PLQY) of 5.71% and a Stokes shift of 75 nm at room temperature. Experimental characterization demonstrates that exciton-like luminescence of Bi^(3+)is mainly responsible for the blue emission. Single crystals of Bi^(3+)-doped(MePPh_(3))_(2)ZnCl_(4) show an unusual correlation between photoluminescence(PL) lifetime and temperature. Particularly, the dependence of luminescence lifetime on temperature is most remarkable in the temperature range of 80 to 100 K with an exceptional sensitivity up to 0.09 K^(-1), representing one of the best levels for thermometry based on PL decay lifetime. Our work not only provides a viable strategy for designing a novel, environmentally friendly, and stable blue emitter, but also paves the way for precise thermometric application at low temperature.

关键词： lead-free hybrids Bi^(3+)doping blue emission temperature sensing