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Monitoring of rice crop using ENVISAT ASAR data

Science china Earth sciences 2006年第7期49卷 755-763页

作者： DONG Yanfang1, 2. SUN Guoqing1,3 & PANG Yong4 1. State Key Laboratory of Remote Sensing Science, institute of Remote Sensing Applications, chinese academy of sciences, Beijing 100101,{2. 2. Graduate University of chinese academy of sciences, Beijing 100039,{2. 3. Department of geography, University of Maryland, College Park, MD 2.742. USA 4. Forest Remote Sensing Lab, Research institute of Forest Resource and Information Technology, chinese academy of For-estry, Beijing 100091,{2. 1. State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China 2. Graduate University of chinese academy of sciences Beijing 100039 China 3. Department of geography University of Maryland College Park MD 20742 USA 4. Forest Remote Sensing Lab Research Institute of Forest Resource and Information Technology Chinese Academy of Forestry Beijing 100091 China

Because of the cloudy conditions during the rice growth period, rice is one of the agri-cultural crops most suited to monitoring with the SAR instruments. Backscatter response measured by SAR is correlated with rice conditions, including height, density, biomass and structure, which are variable at different growing stages. In this paper, multi-date ENVISAT ASAR Alternating Polarization Mode (APMode) imageries were acquired during the rice crop growing cycle. At the same time, the rice parameters were measured in field. A continuous canopy model was used to compute the back-scattering from rice fields during the growth cycle, and the relationship between rice parameters and radar backscattering coefficients from both ASAR and modeling was analyzed. The effects of polari-zation, incidence angle and polarization on radar backscattering coefficients were analyzed. It was found that simulated radar backscatter has similar trends as ASAR data. This will be meaningful for the further research of rice parameters estimation from ASAR data. Different features show signifi-cantly different signatures in ASAR images and they follow some certain laws, so rice area can be accurately mapped by using multi-temporal SAR images, then rice yield can be estimated.

关键词： rice, ASAR, radar backscattering, model.

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Downstream effects of reservoirs in areas suffering from water deficiency-the case of Hutuo River, china

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Journal of Geographical sciences 2000年第1期10卷 37-44页

作者： SHI Chang-xing (institute of geography,{2. academy of sciences, Beijing 100101, china)

The Hutuo River is located in the semi-arid areas in china. Due to fat of water resources in these areas, changes in flow regime, mainly reduction in runoff downstream from the reservoirs, have been tremendous. As a result of decrease in flow power and sediment load, the post-dam river showed a less change in channel morphology and the change varied reach by reach. Comparatively, the channel shrinkage may contribute to the flood disasters in the lower reaches of the river in recent years. An obvious increase of channel's hydraulic roughness, the main cause for reduction of flood transmission capacity of the channel, is attributed to vegetation encroachment in the channel. The effects of reservoir construction on ground water level and other environmental aspects are also discussed in the paper.

关键词： Hutuo River, pest-dam channel adjustment channel's roughness environmental effect

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Deduction and application of generalized Euler formula in topological relation of geographic information system (GIS)

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Science china Earth sciences 2004年第8期47卷 749-759页

作者： ZHANG Shuqing1, ZHANG Junyan1,2.& ZHANG Bai1 Northeast institute of geography and Agricultural Ecology,{2., Changchun 130012. china Northeast Design institute of china City Planning and Engineering, Changchun 130012. china 1. Northeast institute of geography and Agricultural Ecology Chinese Academy of Sciences 130012 Changchun China 2. Northeast Design institute of china City Planning and Engineering 130012 Changchun China

By combining geographic information system (GIS), a new conception of “group” in which covers the complex connected region is introduced in the paper. Based on the conception of group, a generalized Euler formula and its properties are deduced and proved. The paper also describes the mathematical principles of generating topological information of polygon in GIS maps and the methods for checking up the veracity of topological relations of the map with Euler formula and general Euler formula. We have also obtained the quantitative relations among real nodes, chains, islands and groups with the formulas. At the same time, the paper introduces Whole Sphere Stereographic (WSS) projection into the GIS, and defines a new conception of “sea”. The deduction of general Euler formula and the introduction of WSS projection to GIS have developed new ways of delineating GIS topological models from plane to sphere and even constructing three dimensional (3-D) topological models.

关键词： Euler formula,general Euler formula,geographic information system,topological relation.

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An examination on several key problems inchina's urbanization process

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Journal of Geographical sciences 1999年第3期9卷 280-286页

作者： YAO Shi-mou Xiu-min, Roger Chan(1. nanjing institute of {2. chinese academy of sciences, nanjing 2.008, china 2.The University of Hong Kong)

Industrialization is the leading factor to urbanization which is the inexorable trend ofeconomic construction. In the future urbanization process three key problems are identified as I)relation between urban construction and cultivared land protetion, 2. how to take china's way tourbanization, and 3) china should take the Way of nd and urban coordination and forbid to occupyagricultural land for blind urbsn condtruction.

关键词： urbanization process farmland conversion environment protection

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Analysis on reasons for the Yellow River’s dry-up and its eco-environmental impacts

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Journal of Environmental sciences 1998年第3期 102+105+107-109+104+页

作者： Gao Yanchun institute of geography,{2., Beijing 100101, china

ＡｎａｌｙｓｉｓｏｎｒｅａｓｏｎｓｆｏｒｔｈｅＹｅｌｏｗＲｉｖｅｒ’ｓｄｒｙｕｐａｎｄｉｔｓｅｃｏｅｎｖｉｒｏｎｍｅｎｔａｌｉｍｐａｃｔｓＧａｏＹａｎｃｈｕｎＩｎｓｔｉｔｕｔｅｏｆＧｅｏｇｒａｐｈｙ，Ｃｈｉｎ... 详细信息

ＡｎａｌｙｓｉｓｏｎｒｅａｓｏｎｓｆｏｒｔｈｅＹｅｌｏｗＲｉｖｅｒ’ｓｄｒｙｕｐａｎｄｉｔｓｅｃｏｅｎｖｉｒｏｎｍｅｎｔａｌｉｍｐａｃｔｓＧａｏＹａｎｃｈｕｎＩｎｓｔｉｔｕｔｅｏｆＧｅｏｇｒａｐｈｙ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎ...

关键词： Yellow River runoff change human activities dry-up eco-environmental impacts.

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Carbon Storage and Vertical Distribution in Three Shrubland Communities in Gurbantünggüt Desert,Uygur AutonomousRegion of Xinjiang,Northwest china

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chinese Geographical Science 2012年第5期22卷 541-549页

作者： GONG Yanming 1 ,HU Yukun 1 ,FANG Fei 1 ,LIU Yanyan 1 ,LI Kaihui 1 ,ZHANG Guangming 2.(1.Key Laboratory of Biogeography and Bioresource in Arid Land,Xinjiang institute of Ecology and geography,chinese academy of sciences,Urumqi 830011,china 2.State Key Laboratory of Vegetation and Environmental Change, institute of Botany,chinese academy of sciences,Beijing 100093,china) 1. Key Laboratory of Biogeography and Bioresource in Arid Land Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China 2. State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China

This study was carried out in the Gurbantünggüt Desert,Uygur Autonomous Region of Xinjiang,Northwest china in August,*** quantify the storage,contribution and vertical distribution patterns of plant biomass carbon (PBC)and soil organic carbon(SOC)in the study area,we investigated the carbon concentrations and its vertical distribution in three different desert shrubland communities dominated by Reaumuria soongorica,Haloxylon ammodendron+*** and Tamarix ramosissima+***,*** analyzed vertical distribution of root biomass carbon and soil carbon contents by excavating soil profiles for each dominated *** results show that SOC is considerably the larger carbon pool in the soil layers of 1.0-3.0 m(the mean value of three shrubland communities is 38.46%)and 3.0-5.0 m(the mean value is 40.2.%).In contrast,70.74%of belowground biomass carbon storage in 0-1.0 m layer,and its content decrease with increasing soil *** Haloxylon ammodendron+R. soongorica shrubland community has the highest belowground biomass carbon among three selected communities. This study highlights the importance of SOC stored in deep soil layers(lower than 3.0 m from the surface)in arid shrubland communities in the global carbon *** addition,it provides the data support for revealing deep soil solid carbon potential,and offers scientific basis for the further research in the carbon cycle of terrestrial ecosystem.

关键词： shrubland community plant biomass carbon soil organic carbon vertical distribution Gurbantünggüt desert

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Estimating forest aboveground biomass using HJ-1 Satellite CCD and ICESat GLAS waveform data

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Science china Earth sciences 2010年第S1期53卷 16-25页

作者： GUO ZhiFeng1,CHI Hong1,2.& SUN GuoQing1,3 1State Key Laboratory of Remote Sensing Science,Jointly Sponsored by the institute of Remote Sensing Applications of chinese academy of sciences and Beijing Normal University,institute of Remote Sensing Applications,chinese academy of sciences,Beijing 100101,china 2.raduate University of chinese academy of sciences,Beijing 100049,china 3Department of geography University of Maryland,College Park,MD 2.742.USA 1. State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Department of Geography University of Maryland College Park MD 20742 USA

The ecosystem in northeastern china and the Russian Far East is a hotspot of scientific research into the global carbon *** aboveground biomass(AGB) is an important component in the land surface carbon *** this study,using forest inventory data and forest distribution data,the AGB was estimated for forest in Daxinganlin in northeastern china by combining charge-coupled device(CCD) data from the Small Satellite for Disaster and Environment Monitoring and Forecast(HJ-1) and Geoscience Laser Altimeter System(GLAS) waveform data from the Ice,Cloud and land Elevation Satellite(ICESat).The forest AGB prediction models were separately developed for different forest types in the research area at GLAS footprint level from GLAS waveform parameters and field survey plot biomass in the Changqing(CQ) Forest Center,which was calculated from forest inventory *** resulted statistical regression models have a R2.0.68 for conifer and R2.0.71 for broadleaf *** models were used to estimate biomass for all GLAS footprints of forest located in the study *** GLAS footprint biomass coupled with various spectral reflectivity parameters and vegetation indices derived from HJ-1 satellite CCD data were used in multiple regression analyses to establish biomass prediction models(R2.0.55 and R2.0.52.for needle and broadleaf respectively).Then the models were used to produce a forest AGB map for the whole study area using the HJ-1 *** data obtained from forest inventory data of the Zhuanglin(ZL) Forest Center were used as independent field measurements to validate the AGB estimated from HJ-1 CCD data(R2.0.71).About 80% of biomass samples had an error less than 2. t ha-1,and the mean error of all validation samples is 5.74 t *** pixel-level biomass map was then stratified into different biomass levels to illustrate the AGB spatial distribution pattern in this *** was found that HJ-1 wide-swath data and GLAS waveform data can be combined to estim

关键词： Disaster and Environment Monitoring and Forecast Satellite ICESat GLAS waveform boreal forest forest aboveground biomass multiple linear regression

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Strengthening integrated research of geography and accepting challenges of the new century—celebrating the 90th birthday of the Geographical Society of china

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Journal of Geographical sciences 1999年第4期9卷 317-318页

作者： ZHENG Du(institute of geography,{2., Beijing 100101, china)

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Improvement of modelling accuracy by using high resolution soil data in a coupled surface-subsurface water flow model

Improvement of modelling accuracy by using high resolution s...

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2.11 World Congress on Engineering and Technology(CET 2.11)

作者： Qi Zhang State Key Laboratory of Lake Science and Environment nanjing institute of {2. and limnology chinese academy of sciences nanjing 210008 china Jinling Yang institute of Soil Science chinese academy of sciences nanjing 210008 china

This paper tested the effects of refined soil property on the hydrological modelling results, exemplified in the surface runoff-groundwater coupled model for Xitiaoxi catchment, Lake Taihu basin, by extending the previous study where a relatively coarse soil map was used. This study finds that the refined soil property, associated with a finer model grid size significantly improves the accuracy in modelling the stream flow for dry seasons, when the groundwater base flow （groundwater discharged to rivers） dominates the stream flow. Since the groundwater base flow is highly dependent on the soil water percolation processes, the accurate simulation of base flow requires an accurate representation of the soil property and soil water processes. This finding implies that the soil resolution may affect the partitioning of surface and subsurface water flow, and should be appropriately considered in coupled simulation of surface and subsurface water flow, especially for the cases that stream flow simulations for dry seasons demand for a high accuracy.

关键词： Soil resolution surface-subsurface water flow modelling accuracy dry seasons WATLAC Xitiaoxi catchment

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ANALYSIS OF THE EXPANSION OF THE BUILT-UP AREA OF DALIAN CITY

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chinese Geographical Science 2002年第4期12卷 373-377页

作者： CHANG Li-ping,ZHANG Shu-wen(Changchun institute of geography,t he{2.,Changchun 130012.P.R.china) Changchun institute of geography the Chinese Academy of Sciences Changchun P. R. China

With the astounding development and gradual improvement of remote sensing technology,as an advanced science technology,it is used to pro vide multi-temporal,large scope re al-time information for land-use dynamic change,and also is one of the best efficient m ethods for studying the earth resour ces and *** sensing image has its characteristics of ample inform ation and reflecting the objective r *** paper uses multi-temp oral TM images in1986,1996and 2.00,and relevant sta tistic data to analyze land-use chan ges of Dalian City in Liaoning Provin ce of Chi-na over ten years by means of the corre lation analysis *** results have shown that two methods could con-formably reflect the present land-u se *** is closely c orrelative to natural factors and ec onomic *** in recent 2.years,under the influence of the reform and open-up policy,Dalian,as a specifi c coast city,is becoming an international m etropolis.

关键词： land-use change remote sensing driving force dalian city

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