检索结果-南通市图书馆

Wuhan University Journal of Natural Sciences 2005年第4期10卷 779-784页

作者： zhang Ren-jun 1,2.1. institute of {2. hazards and environment, chinese academy of Sciences, chengdu 610041, sichuan, china 2. Graduated School of the chinese academy of Sciences, Beijing 10003., china institute of {1. {2. and {3. Chinese Academy of Sciences Chengdu Sichuan China Graduated School of the chinese {1. of Sciences Beijing China

Based on the study of visitors' individual spatial behaviors, a tourists'spatial behavior simulator (TSBS) to assess the carrying capacity of tourist resorts was developed,TSBS employs GIS (Geographic Information System) to manage the spatial data,and Multi-Agent systemto simulate the actions of individual visitors. By utilizing TSBS, visitors' travel patterns such aslocation, cost, and state can be analyzed and predicted. Based on this analysis and prediction, themodel of assessing the carrying capacity of resorts is built. Our results show that TSBS will be aneffective tool to accurately assess the carrying capacity of tourist resorts.

关键词： tourist resort carrying capacity TSBS GIS Multi-Agent simulator

Ecological Footprint and Ecological Security Evaluation in the Upper Min River Basin

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2005年第4期10卷 641-646页

作者： TU Jian-jun 1, 2.1. School of Resources and environment Science, Southwest{2. Normal University, Chongqing 400715,{2. 2. institute of mountain hazards and environment, chinese academy of Sciences, chengdu 610041, sichuan,{2. School of Resources and environment Science Southwest China Normal University Chongqing China institute of {1. {2. and {3. Chinese Academy of Sciences Chengdu Sichuan China

On the basis of the ecological footprint (EF) model, this paper studied theecological security in the Upper Min River Basin ecosystem. The result shows that with 2. 0{1. 2.hm^2.er capita ecological capacity (0. 42. 2.h... 详细信息

On the basis of the ecological footprint (EF) model, this paper studied theecological security in the Upper Min River Basin ecosystem. The result shows that with 2. 03. 2.hm^2.er capita ecological capacity (0. 42. 2.hm^2.higher than per capita EF) ,and 165 82. hm^2.ecologysurplus , the ecosystem in Upper Min River is generally secure at present. But the arable land isoverweighed and omens an eco-security crisis. Meanwhile, problems such as low forest coverage rate,severe loss of water and soil,enlargement of arid-valley area, frequent occurrence of mountainhazards and degradation of pastures have been major threats to the eco-security of this region. Thecalculation result of ten-thousand-yuan ( RMB) GDP shows that the use of natural resources isextensive, and there will be a rapid increase tendency of EF in the future. In order to maintain thepresent eco-security, the ways of use natural resources must be improved in the Upper Min RiverBasin.

关键词： ecological security ecological footprint ecological capacity quantitativeevaluation the Upper Min River Basin

Debris Flow Hazard Assessment Based on Support Vector Machine

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2006年第4期11卷 897-900页

作者： yuan lifeng 1, 2.,{2., {3. academy of Sciences, chengdu 610041, sichuan, china 2. Graduate University of {3. academy of Sciences, Beijing 100049, china 3. institute of Geographical Sciences and Natural Resources Research, {3. academy of Sciences, Beijing 100101, china institute of {1. {2. and {3. Chinese Academy of Sciences Chengdu Sichuan China Graduate University of chinese {1. of Sciences Beijing China institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China

Seven factors, including the maximum volume of once flow , occurrence frequency of debris flow , watershed area , main channel length , watershed relative height difference , valley incision density and the length ratio of sediment supplement are chosen as evaluation factors of debris flow hazard degree. Using support vector machine （SVM） theory, we selected 2.9 basic data of {1. debris flow channels in Yunnan Province as learning samples in this study. We create a debris flow hazard assessment model based on SVM. The model was validated though instance applications and showed encouraging results.

关键词： debris flow hazard assessment support vector machine (SVM)

Impact of land-use change on hydrological processes in the Maying River basin, china

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第10期49卷 1098-1110页

作者： WANG Genxu1,3. zhang Yu2. LIU Guimin2.& CHEN Lin3.1. {3. of {2. hazards and environment, chinese academy of Sciences, chengdu 610041, china 2. Cold and Arid Regions environmental and Engineering Research {3., chinese academy of Sciences, Lanzhou 73.000, china 3. Resource and environment School, Lanzhou University, Lanzhou 73.000, china institute of {1. {2. and {3. Chinese Academy of Sciences Chengdu China Resource and environment School Lanzhou University Lanzhou China Cold and Arid Regions environmental and Engineering Research {1. Chinese Academy of Sciences Lanzhou China

Since the 1.60s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of china. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable development on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest china, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. Statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1.65. A runoff model was established composed of two factors, i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large ar- eas of upstream woodland and grassland turned into cultivated lands since 1.67, has resulted in a mean annual runoff decrease of{2..1.2}, a base flow decline of 3..3.2}, a drop in the maximum peak discharge of 3..77%, and mean discharge decreases in spring and autumn of 3..05% and{2..87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73.-81., and that to the influence of base flow reaching 62.-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper development of the entire catchment.

关键词： land-use change, arid inland river catchment, hydrological process, impact, Maying River.

Experimental Analysis of Shear Strength of Undisturbed Soil in Leucaena Forest in Jiangjia Ravine,Yunnan,china

在线全文

学校读者我要写书评

暂无评论

Journal of mountain Science 2010年第4期7卷 386-395页

作者： JIAO Zhen Key Laboratory of mountain {1. and earth surfaceprocesses ChineseAcademy of Sciences Chengdu 610041 China Graduate University of chinese{1. of Sciences Beijing I ooo49 China institute of {1. {2. and {3. Chinese Academy of Science Chengdu 61oo41 China

Five leucaena trees of similar age were chosen in Jiangjia Ravine of Dongchuan,Yunnan Province,china,near which the soil samples were collected by digging profiles{1. in depth and 1. in *** each section,soil samples at different depths were taken for direct shear experiments to determine the root amount and mechanical *** is found that the cohesion and internal friction angle of the undisturbed soil are related to the root amount,depth,clay content and breccias *** correlates negatively with root content,a finding that differs from that of other *** addition,internal friction angle correlates positively with all these factors.

关键词： Jiangjia Ravine Leucaena Undisturbedsoil Shear strength Impact factors

Effect of sediment on concentration of dissolved phosphorus in the Three Gorges Reservoir

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2011年第1期26卷 87-95页

作者： CAO Zhijing~1,zhang Xinbao~2.and AI Nanshan~3.institute of Architecture and {2.,sichuan University,chengdu 610065,china, institute of mountain hazards and {2.,chinese academy of Sciences,chengdu 610041, china, institute of Architecture and {2.,sichuan University,chengdu 610065,china, Lecturer Institute of Architecture and Environment Sichuan University Chengdu 610065 China Prof. Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China Prof. Institute of Architecture and Environment Sichuan University Chengdu 610065 China

Eutrophication and algal bloom has been occurring in the Three Gorges Reservoir ever since the reservoir’s impoundment in *** concentration of dissolved phosphorus(DP) is one of the main controlling factors for algal *** sediment adsorbs DP thereby affecting the concentration of DP. The effect of the sediment reduction on the DP concentration of the Three Gorges Reservoir is discussed in this *** were taken from the Yangtze River and its tributaries,*** Minjiang River and the Tuojiang *** DP concentration of the water samples and the available phosphorus,total phosphorus,and phosphorus-fixing capacity of the sediment samples were *** amount of phosphorus adsorbed by the sediment was about 3.of the total DP load in the Yangtze *** experiment was done in the lab simulating the DP concentration,sediment concentration,and turbulence. The results showed that quite a high amount of DP was adsorbed by the *** adsorption capacity of the sediment was 1.0} mg/kg and the highest rate of adsorption was 2. mg/kg·*** Xiluodu Dam is located at nearly 1.1.0 km upstream of the Three Gorges *** Xiloudu Dam will trap sediment and thence reduce the sediment load entering the Three Gorges Reservoir after impoundment in *** is estimated that the sediment reduction due to the Xiluodu Dam may result in an increase of the DP concentration in the Three Gorges Reservoir by 6.8%.

关键词： Dissolved phosphorus Sediment load reduction Three Gorges Reservoir Adsorption capacity Eutrophication

Prediction of Debris-flow Danger Area by Combining Hydrological and Inundation Simulation Methods

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of mountain Science 2011年第1期8卷 1-9页

作者： CUI Peng Key Laboratory of mountain {1. and Earth Surface Process Chinese Academy of Sciences Chengdu 610041 China institute of {1. {2. and {3. Chinese Academy of Sciences Chengdu 610041 China Graduate School of chinese {1. of Sciences Beijing 100049 China

Debris flows have caused serious human casualties and economic losses in the regions strongly affected by the Ms8.0 Wenchuan earthquake of 2.o8. Debris flow mitigation and risk assessment is a key issue for reconstruction. The existing methods of inundation simulation are based on historical disasters and have no power of prediction. The rain- flood method can not yield detailed flow hydrograph and does not meet the need of inundation simulation. In this paper, the process of water flow was studied by using the Arc-SCS model combined with hydraulic method, and then the debris flow runoff process was calculated using the empirical formula combining the result from Arc-SCS. The peak discharge and runoff duration served as input of inundation simulation. Then, the dangerous area is predicted using kinematic wave method and Manning equation. Taking the debris flow in Huashiban gully in Beichuan County,{1. Province,{2. on 2. Sep. 2.o8 as example, the peak discharge of water flow and debris flow were calculated as 3..52.m3.s-1.and 2.5.66 m3.s-, with error of 4.1.% compared to the measured values. The simulated area of debris-flow deposition was 1.1.500 m2. vs. the measured area of 1.4,097 m2. in error of 81.75%. The simulated maximum depth was 1.2}3.m, consistent with the real maximum depth between lO and 1. m according to the field survey. The minor error is mainly due to the flow impact on buildings and variations in cross-section configuration. The present methodology can be applied to predict debrisflow magnitude and evaluate its risk in other watersheds inthe earthquake area.

关键词： Debris flow Arc-SCS model Inundation simulation Risk analysis Wenchuan earthquake

Preliminary results of the study on wind erosion in the Qinghai-Tibetan Plateau using 1.0}Cs technique

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 2000年第11期45卷 1019-1025页

作者： YAN Ping, DONG Guangrong, zhang Xinbao & zhang Yiyun1. Key Laboratory of {2.al Change and Natural Disaster, the Ministry of Education of{3., Beijing Normal University, Beijing 100875,{3. 2. institute of Desert Research, chinese academy of Sciences, Lanzhou 73.000,{3. 3. institute of mountain hazards and {2., chinese academy of Sciences, chengdu 610041,{3. 4. Department of Physics, sichuan Union University, chengdu 610041,{3. Key Laboratory of environmental Change and Natural Disaster the Ministry of Education of China Beijing Normal University Beijing China institute of Desert Research Chinese Academy of Sciences Lanzhou China institute of {1. {2. and {3. Chinese Academy of Sciences Chengdu China Department of Physics Sichuan Union University Chengdu China

The worldwide fallout of caesium-1.0} (1.0}Cs) associated with the nuclear weapon tests during the 1.50s and 1.60s has provided a valuable man-made tracer for studies of soil erosion and sediment delivery. But relatively few researchers have used it to estimate wind erosion. In this note, the 1.0}Cs technique is introduced into the studies of wind erosion and its modern processes inthe Qinghai-Tibetan Plateau. Two 1.0}Cs reference inventories of 982.1. and 2.3.6.04 Bq · m-2.wereestablished preminarily, distributed in the south and middle-north parts of the studied arearespectively. By analyzing the patterns of 1.0}Cs depth profiles from sampling sites, the aeolianprocesses of erosion and deposition in nearly 40 years have been revealed, i.e. the shrub coppicedunes (S1. and semi-fixed dunefields (S3. experienced the alternation of erosion and deposition,while the grasslands (S4, S6 and S7) and dry farmlands (S5) suffered erosion only. By using 1.0}Csmodel, the average wind erosion rates for shrub coppice

关键词： 1.0}Cs technique Qinghai-Tibetan Plateau wind erosion.

Risk Analysis on Groundwater Resources Carrying Capacity Based on Blind Number Theory

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2007年第4期12卷 669-676页

作者： zhang Ji1,2.YU Sujun3.. Key Laboratory of mountain {2. and Surface Process,chinese academy of Sciences/institute of mountain {2. and environment,chinese academy of Sciences,chengdu {12.,sichuan,china 2. Graduate University of the chinese academy of Sciences,Beijing 100049,china 3. School of environmental Science and Engineering,Southwest Jiaotong University,chengdu {12.,sichuan,china Key Laboratory of mountain {1. and Surface Process Chinese Academy of Sciences Chengdu China Graduate University of the chinese {1. of Sciences Beijing China institute of {1. {2. and {3. Chinese Academy of Sciences Chengdu China School of environmental Science and Engineering Southwest Jiaotong University Chengdu China

Blind numbers of evaluation indices about groundwater resources carrying capacity are defined from the concomitancy of randomness, fuzziness, grey property and unascertainment of groundwater system. Based on fuzzy theory, a comprehensive evaluation model on groundwater resources carrying capacity is constructed with blind information. Then a risk assessment model of surcharge about groundwater resources carrying capacity is established on blind reliability theory. The probable value ＂＊＂ matrix of fuzzy membership degree about carrying capacity corresponding to each judgment level can be obtained with the aid of blind algorithm as well as the subjective reliability ＂×＂ matrix. And then a graph of ＂groundwater carrying capacity v.s. accumulative reliability＂ can be gained Based on the graph, fuzzy membership degree of groundwater resources carrying capacity to each judgment level under different risk probability can be got. Thus, a comparatively reasonable judgment to groundwater resources carrying capacity might be obtained, with comprehensive analysis to the state of society, economy technology and ecology.

关键词： blind number theory groundwater resources carrying capacity evaluation risk analysis

Initiation and Development of Water Film by Seepage

在线全文

学校读者我要写书评

暂无评论

Journal of mountain Science 2010年第4期7卷 361-366页

作者： LU Xiaobing CUI Peng HU Kaiheng zhang Xuhui institute of Mechanics Chinese Academy of Sciences Beijing 100080 China institute of {1. {2. & {3. Chinese Academy of Sciences Chengdu 610041 China

When water seeps upwards through a saturated soil layer,the soil layer may become instability and water films occur and *** film serves as a natural sliding surface because of its very small ***,debris flow may *** investigate this phenomenon,a pseudothree-phase media is presented *** discontinuity method is used to analyze the expansion velocity of water ***,perturbation method is used to analyze the case that a water flow is forced to seep upwards through the soil layer while the movement of the skeleton may be neglected relative to that of *** theoretical evolutions of pore pressure gradient,effective stress,water velocity,the porosity and the eroded fine grains are *** can be seen clearly that with the erosion and redeposited of fine grains,permeability at some positions in the soil layer becomes smaller and smaller and,the pore pressure gradient becomes bigger and bigger,while the effective stress becomes smaller and *** the effective stress equals zero,***,the water film *** is shown also that once a water film occurs,it will be expanded in a speed of U(t)(1.ε).

关键词： Slope Seepage Debris flow Water film