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A study on determining the location of groundwater divide using a mathematical morphology method

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Science china(Technological Sciences) 2006年第z2期49卷 141-148页

作者： PAN Yun, GONG Huili, DUAN Fuzhou & HU Zhuowei key laboratory of 3. Information Acquisition and Application,{2., Capital {3. university, beijing 10003., china key laboratory of Resource Environment and GIS of beijing, Capital {3. university, beijing 10003., china Capital normal Univ Minist Educ Key Lab D Informat Acquisit & Applicat 3 Beijing 100037 Peoples R China Capital normal Univ Key Lab Resource Environm Beijing 100037 Peoples R China Capital normal Univ GIS Beijing Beijing 100037 Peoples R China

Placement of a groundwater divide indicates sink areas and spatial distribution, knowledge of which helps in the mapping of regional aquifer properties and the management of groundwater resources. By applying mathematical morphology to a conceptual model of a watershed and characteristic erosion and dilation operations, this paper proposes a structuring element with which to extract the shape and location of groundwater divide. With due consideration to watershed linearity, a structuring element with three origins is designed to connect watershed points. After erosion, closing, and dilation operations, the groundwater divide is determined; the results indicate this method's feasibility and accuracy.

关键词： groundwater divide, mathematical morphology, structuring element.

Scenario simulation and forecast of land use/cover in northern china

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Chinese Science Bulletin 2008年第9期53卷 1401-1412页

作者： LI YueChen 1,2.3.& HE ChunYang 3.1 College of Geographical Science, Chongqing normal university, Chongqing 400047,{2. 2.College of Resources and environmental Science, Chongqing university, Chongqing 400044,{2. 3.College of Resources Science & Technology, beijing normal university, beijing 100875,{2. College of Geographical Science Chongqing Normal University Chongqing 400047 China College of Resources and environmental Science Chongqing University Chongqing 400044 China College of Resources Science & Technology Beijing Normal University Beijing 100875 China

Modeling land use/cover scenario changes and its potential impacts on structure and functions of ecosystem in typical regions are helpful to understanding the interactive mechanism between land use/cover system and ecosystem. Based on the analysis of the existing land use/cover simulation and forecast models, a land use/cover scenario dynamics model by the integration of System Dynamics (SD) model, Back Propagation Neural Network (BPNN) and Cellular Automata (CA) model is developed with land use/cover scenario changes in northern china in the next 3. years and simulated in this paper. The model is to simulate the land use/cover scenario demands by using a SD model at first, and then allocating the land use scenario patterns at the local scale with the considerations of land use/cover suitability, inheritance ability and neighborhood effect by using BPNN-CA model to satisfy the balance between land use/cover scenario demands and supplies. It integrates the advantages of SD, BPNN and CA. Macro-driving factors and the micro-spatial pattern are also fully taken into account. The BPNN simplifies the identification of the factors’ weights used in CA model and improves the reliability of the simulation results. The simulation accuracy of the model developed in this paper was found to be about 74%. It suggests that the model has the ability to reflect the complexity of land use/cover system at different scales to some extent and it is a useful tool for assessing the potential impacts of land use system on ecosystem. The simulated results also indicate that the urban land, water area and forest will increase significantly, and farmland and unable land will decrease gradually. Obvious land use/cover changes will take place in the farming-pastoral zone and the southeast area of northern china.

关键词：土地利用中国北方细胞自动机系统动力学

Spatial patterns in temperature sensitivity of soil respiration in china: Estimation with inverse modeling

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Science china(Life Sciences) 2009年第10期52卷 982-989页

作者： ZHOU Tao1,2. SHI PeiJun1,2. HUI DaFeng3.& LUO YiQi4 1 State key {3. of Earth Surface Processes and Resource Ecology,{2., beijing 100875, china 2.Academy of disaster Reduction and Emergency Management, ministry of Civil Affairs & ministry of education, beijing 100875, china 3.Department of Biological Sciences, Tennessee State {13., Nashville, TN 3.2.9, USA 4 Department of Botany and Microbiology, {13. of Oklahoma, Norman, OK 73.19, USA 1. State key laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Beijing 100875 China 2. Academy of disaster Reduction and Emergency Management Ministry of Civil Affairs & Ministry of Education Beijing 100875 China 3. Department of Biological Sciences Tennessee State University Nashville TN 37209 USA 4. Department of Botany and Microbiology University of Oklahoma Norman OK 73019 USA

Temperature sensitivity of soil respiration (Q10) is an important parameter in modeling the effects of global warming on ecosystem carbon release. Experimental studies of soil respiration have ubiquitously indicated that Q10 has high spatial heterogeneity. However, most biogeochemical models still use a constant Q10 in projecting future climate change and no spatial pattern of Q10 values at large scales has been derived. In this study, we conducted an inverse modeling analysis to retrieve the spatial pattern of Q10 in china at 8 km spatial resolution by assimilating data of soil organic carbon into a proc-ess-based terrestrial carbon model (CASA model). The results indicate that the optimized Q10 values are spatially heterogeneous and consistent to the values derived from soil respiration observations. The mean Q10 values of different soil types range from 1.09 to 2.3., with the highest value in volcanic soil, and the lowest value in cold brown calcic soil. The spatial pattern of Q10 is related to environmental factors, especially precipitation and top soil organic carbon content. This study demonstrates that inverse modeling is a useful tool in deriving the spatial pattern of Q10 at large scales, with which being incorporated into biogeochemical models, uncertainty in the projection of future carbon dynamics could be potentially reduced.

关键词： temperature sensitivity Q10 soil respiration global warming inverse analysis

A 2.00-year sea level change record in Fildes Peninsula, Antarctica

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Progress in natural Science:Materials International 2004年第8期 65-67页

作者： ZHAO Ye*(Department of Resource and environmental Sciences key {2. of environmental Change and natural disaster, ministry of education of china, beijing normal university, beijing 100875, china) Department of Resource and environmental Sciences key laboratory of {2. Change and {3. disaster Ministry of Education of China Beijing Normal University Beijing 100875 China

A detailed record of sea level changes during the last 2.00 years is preserved in the northernwest coast of Fildes Peninsula in Antarctica. Fourteen marine alga layers were deposited in the beach with an altitude of 2.80 m, and one diatom layer deposited in the ancient lake on the terrace with an altitude of 6.84 m. A radiocarbon age of 695±70 aBP was obtained for the modern marine alga, and the age was used in correction for the carbon reservoir effect of the marine alga. Sea level fell 4.98 m from the 4th century B.C. to the early 13.h century, at an average of -0.3. cm/a, then rose about 0.78 m during the early 13.h to the middle 18th century, at an average of 0.14 cm/a. It has risen about 0.16 m since the middle 18th century, at an average of 0.07 cm/a.

关键词： Antarctica Fildes Peninsula Late Holocene sea level changes.

A technique on automatic land-use database reconstruction based on scanning land-use map

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Science china(Technological Sciences) 2006年第z2期49卷 57-63页

作者： LI Xiaojuan, GONG Huili, YIN Lianwang, SUN Yonghua, YANG Lingli & WANG Yanggang key laboratory of 3. Information Acquisition and Application,{2., Capital {3. university, beijing 10003., china key laboratory of Resource Environment and GIS of beijing, Capital {3. university, beijing 10003., china Capital normal Univ Minist Educ Key Lab D Informat Acquisit & Applicat 3 Beijing 100037 Peoples R China Capital normal Univ Key Lab Resource Environm Beijing 100037 Peoples R China Capital normal Univ GIS Beijing Beijing 100037 Peoples R China

Although a land-cover database is very important to national land use including urban planning and land-use management, it is very laborious and time-consuming to build through digitization of paper land-use maps (1:10000) and data input by hand. Here we propose a new, high-level, automatic technique to build a land-use database, which has proved useful and practical in building a land-use database of Baotou City.

关键词： land-use map vectonzation automatic building of land-use database.

Parameter determination to calculate water environmental capacity in Zhangweinan Canal Sub-basin in china

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Journal of environmental Sciences 2010年第6期22卷 904-907页

作者： Yingxia Li ,Ruzhi Qiu,Zhifeng Yang,Chunhui Li,Jingshan Yu State key laboratory of Water Environment Simulation,School of Environment,{2. {3. university,{2.,100875,china. [a] State key laboratory of Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China

Zhangweinan canal sub-basin （ZWN） has the most serious water resource shortage and water pollution problems in north of china. To calculate the water environmental capacity in ZWN, determination methods for design flow rates and degradation coefficients were discussed in this study. Results showed that 90% and 50% hydrological guarantee flow rates were suitable to be the design flow rates for rainy and dry seasons, respectively. Degradation coefficients of CODMn and NH3.N were 0.2. day^-1 and 0.15 day^-1 for branch streams and 0.5 day^-1 and 0.2. day^-1 for mainstreams, respectively in ZWN. With one-dimensional water quality simulation model, water environmental capacities were calculated to be 82.13. tons/yr for CODMn and 2.94 tons/yr for NH3.N in ZWN.

关键词： degradation coefficient design flow rate water environmental capacity Zhangweinan

Evidence from carbon isotope measurements for biological origins of individual long-chain n-alkanes in sediments from the Nansha Sea,china

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Chinese Science Bulletin 2002年第7期47卷 578-581页

作者： DUAN Yi & WANG ZhipingState key laboratory of Gas Geochemistry, Lanzhou Institute of Geology, Chinese Academy of Sciences, Lanzhou 73.000,{2. Institute of {3. Science, beijing normal university, beijing 100875,{2. 1. State key laboratory of Gas Geochemistry Lanzhou Institute of Geology Chinese Academy of Sciences 730000 Lanzhou China 2. Institute of environmental Science Beijing Normal University 100875 Beijing China

Carbon isotopes are measured for individual long-chain n-alkanes in sediments from the Nansha Sea. The features of carbon isotopic compositions of individual n-alkanes and their origins are studied. The results show that the long-chain n-alkanes have a light carbon isotopic composition and a genetic feature of mixing sources, and low-latitude higher plants and microbes are considered to be their main end member sources. Based on the abundances and carbon isotopic compositions of individual n-alkanes, the fractional contributions of the two end member sources to individual n-alkanes are quantitatively calculated by using a mixing model. The obtained data indicate that the fractional contributions of the two biological sources are different in the three samples. A trend is that the contribution of microbes increases with the depth. These results provide the theory basis and quantitatively studied method for carbon isotopic applied research of individual n-alkanes.

关键词： modern marine sediment individual n-alkane carbon isotopic composition biological source.

Principle of small target detection for hyperspectral imagery

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Science china Earth Sciences 2007年第8期50卷 1225-1231页

作者： GENG XiuRui1,2.3.& ZHAO YongChao2.3.4 1 Research Center for Remote Sensing and GIS, Department of Geography, beijing normal university,{3.,{2. 2.State key laboratory of Remote Sensing Science, Chinese Academy of Sciences, beijing 100101,{2. 3.Institute of Erectronics, Chinese Academy of Sciences, beijing 100080,{2. 4 Center for for Assessment and Monitoring of Forest and environmental Resources and Division of Ecosystem Sciences {13. of California Berkeley, CA 9472.-3.14, USA 1. Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University Beijing 100875 China 2. State key laboratory of Remote Sensing Science Chinese Academy of Sciences Beijing 100101 China 3. Institute of Erectronics Chinese Academy of Sciences Beijing 100080 China 4. Center for for Assessment and Monitoring of Forest and environmental Resources and Division of Ecosystem Sciences University of California Berkeley CA 94720-3114 USA

This paper generalizes the progress of algorithms in small target detection for hyperspectral imaging, and finds that whitening the image is the key point of many methods in small target detection. An al-gorithm is presented to detect desired targets by converting large targets into small ones based on the weighted sample autocorrelation matrix.

关键词： hyperspectral whiten target detection

Level Set interface treatment and its application in Euler method

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 227-236页

作者： WU KaiTeng1,2.HAO Li3.WANG Cheng4 & ZHANG Li1,2.1 Numerical Simulation Sichuan Higher School key {3.,Neijiang {2. university,Neijiang 641112.china 2.College of Mathematics and Information Science,Neijiang {2. university,Neijiang 641112.china 3.College of Science,{13. university of Civil Engineering and Architecture,{13. 100044,china 4 State key {3. of Explosion Science and Technology,{13. Institute of Technology,{13. 100081,china 1. Numerical Simulation Sichuan Higher School key laboratory Neijiang Normal University Neijiang 641112 China2. College of Mathematics and Information Science Neijiang Normal University Neijiang 641112 China3. College of Science Beijing University of Civil Engineering and Architecture Beijing 100044 China4. State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China

Level Set interface treatment method is introduced into Euler method,which is employed for interface treatment method for multi-materials. Combined with the ghost fluid method,the moving interface is tracked. Fifth-order WENO spatial discretization and third-order TVD Runge-Kutta time discretization methods are used. Shock-wave action on bubble,implosion and velocity field Shock effect bubbles; implosion and velocity field are simulated by means of LS-MMIC3. programmed by C++. Nu-merical results show that the Level Set interface treatment method is effective and feasible for multi-material interface treatment in comparison with the WENO method.

关键词： Euler method Level Set method shock-wave action on bubble implosion numerical simulation