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Monitoring on soil erosion and sediment delivery at a typical basin of the middle and lower reaches of the Jialing River by remote sensing

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中国科学：技术科学英文版 2003年第z1期46卷 148-155页

作者： FAN Jianrong, ZHONG Xianghao & LIU Shuzhen institute of mountain {2. and environment, chinese academy of sciences and Ministry of Water Resources, chengdu 61004., china chinese Acad Sci Inst Mt Hazards & Environm Chengdu 610041 Peoples R China Minist Water Resources Chengdu 610041 Peoples R China

The monitoring work was performed on soil erosion in Lizixi drainage area respectively in 1986 and 1999 by multiple methods with the information extracted from the Landsat TM imagery and Spot imagery. The variation of erosion quantity in this area is calculated based on the monitoring result of the erosion intensity and area in these two years. The change of sediment delivery is also analyzed. The research result shows that compared to 1986, in 1999, the erosion area reduced, especially for the area of moderate intensity and above, and the intensity and quantity of erosion decreased. Compared to this period from 1965 to 1986, the sediment delivery ratio has been changed from 0.2. to 0.11 after 1986. The research result could help the decision-making for further water and soil conversation work in Lizixi drainage area, and it also offers reference for monitoring,evaluating and predicting soil erosion in other drainage areas.

关键词： drainage area, soil erosion, remote sensing, sediment delivery.

Land Use of the Three Gorges Reservoir Area and the Effect on Its Landscape Pattern in the Recent 50 Years

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Wuhan University Journal of Natural sciences 2006年第4期11卷 910-914页

作者： HUANG Zhiqin 1,2.3 , ZHOU Wancun 1 ,ZHOU Jieming 4 , ZHU Mingcang 3,5 1. institute of mountain {2. and environment, chinese academy of sciences , chengdu 61004., sichuan, china 2. Graduate University of chinese academy of sciences, Beijing 100049, china 3. sichuan institute of Land Resource Management, chengdu 61004., sichuan , china 4. Department of Resources and environment Science, sichuan Normal University , chengdu 610061, sichuan, china 5. College of Information Engineering, chengdu University of Technology, chengdu 610059, sichuan, china institute of mountain {2. and environment Chinese Academy of Sciences Chengdu Sichuan China Graduate University of chinese academy of sciences Beijing China sichuan institute of Land Resource Management Chengdu Sichuan China Department of Resources and environment Science Sichuan Normal University Chengdu Sichuan China College of Information Engineering Chengdu University of Technology Chengdu Sichuan China

The paper makes detailed analysis on the changing processes of the main types of land use in Three Gorges Reservoir Area through the techniques of RS （Remote Sense） and GIS （Geography Information System）. Based on the theory of landscape ecology, many types of landscape pattern indexes are calculated and made correlation analysis. The results indicate that： in 1995 the ecological environment of Three Gorges Reservoir Area was the most vulnerable in the recent 50 years, but resumed in 2.02. the landscape pattern diversity index, fractal dimension index and fragmentation index has close correlation with the area of land use/cover change （LUCC）. The research also releases that the increase of the cultivated land, grassland and construction land deteriorates the landscape ecological pattern, while the increase of forest land area will help restore the landscape ecological pattern to its original state. The rapid change of grassland is an important index of the change of landscape pattern, because it has the most effect on change of landscape pattern index.

关键词： the Three Gorges Reservoir Area land use/cover change landscape pattern.

Forecast Method of Multimode System for Debris Flow Risk Assessment in Qingping Town,sichuan Province,china

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Journal of mountain Science 2011年第4期8卷 592-602页

作者： KONG Jiming Key Laboratory of mountain hazards and Earth Surface Processes Chinese Academy of Sciences institute of mountain {2. and environment Chinese Academy of Sciences

The Wenchuan Earthquake of May 12.2.08 triggered large numbers of *** heavy rain on 13 August 2.10 triggered debris flows with total volume of more than 6 million cubic meters and the debris flows destroyed 500 houses and infrastructure built after the Wenchuan *** study area Qingping Town was located in the northwestern part of the sichuan Basin of china,which needs the second reconstructions and the critical evaluation of debris *** study takes basin as the study unit and defines collapse,landslide and debris flow hazard as a geo-hazard system.A multimode system composed of principal series system and secondary parallel system were established to evaluate the hazard grade of debris flow in 138 drainage basins of Qingping *** evaluation result shows that 30.43% of study basins(42.basins) and 2..58% of study area,are in extremely high or high hazard grades,and both percentage of basin quantity and percentage of area in different hazard grades decrease with the increase of hazard *** to the geo-hazard data from the interpretation of unmanned plane image with a 0.5-m resolution and field investigation after the Wenchuan Earthquake and 8.13 Big Debris Flow,the ratio of landslides and collapses increased after the Wenchuan Earthquake and the ratios of extremely high or high hazard grades were more than moderate or low hazard grades obviously.2. geo-{2. after8.13 Big Debris Flow in Qingping town region all occurred in basins with extremely high or high hazard grades,and 9 debris flows were in basins with extremely high hazard *** model of multimode system for critical evaluation could forecast not only the collapse and landslide but also the debris flow precisely when the basin was taken as the study unit.

关键词： Multimode System Risk assessment Debris flow Landslide Wenchuan Earthquake Qingping Town

ANALYSIS ON POVERTY IN mountain AREAS BASED ON OFF-FARM INDUSTRIES

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chinese Geographical Science 2003年第4期13卷 359-363页

作者： WANG Qing, LI Hui-xia, CHEN Guo-jie, CHEN Yong(institute of mountain {2. and environment,chinese academy of sciences,chengdu 61004.,P. R. china) institute of mountain {2. and environment Chinese Academy of Sciences Chengdu P. R. China

This paper reveals that agricultural growth trend in china is strongly correlated with the growth of off-farm industries-the curve of net income from off-farm industries reflects the general characteristics of net income of households. That means the increase of net income of farm households is chiefly from off-farm industries,more than from agriculture. The authors therefore conclude that the "poverty" in mountain areas or the gap between mountain areas and plain areas lies in the underdevelopment of off-farm industries in mountain areas. Finally,the authors make suggestions of strategic adjustment of economic structure: 1) present situation of mountain areas in china should be fully considered; 2. a full industrial system is not our desire; 3) advantageous industries should be promoted to create famous products; 4) industrialization and urbanization in mountain areas should be promoted and so on.

关键词： regional developmental difference off-farm industry per capita net income mountain areas of china

Preliminary results of the study on wind erosion in the Qinghai-Tibetan Plateau using 137Cs technique

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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 environmental Change and Natural Disaster, the Ministry of Education of china, Beijing Normal University, Beijing 100875, china 2. institute of Desert Research, chinese academy of sciences, Lanzhou 730000, china 3. institute of mountain hazards and environment, chinese academy of sciences, chengdu 61004., china 4. Department of Physics, sichuan Union University, chengdu 61004., china 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 mountain {2. and environment Chinese Academy of Sciences Chengdu China Department of Physics Sichuan Union University Chengdu China

The worldwide fallout of caesium-137 (137Cs) associated with the nuclear weapon tests during the 1950s and 1960s 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 137Cs technique is introduced into the studies of wind erosion and its modern processes inthe Qinghai-Tibetan Plateau. Two 137Cs reference inventories of 982.11 and 2.376.04 Bq · m-2.wereestablished preminarily, distributed in the south and middle-north parts of the studied arearespectively. By analyzing the patterns of 137Cs 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 137Csmodel, the average wind erosion rates for shrub coppice

关键词： 137Cs technique Qinghai-Tibetan Plateau wind erosion.

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

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

作者： JIAO Zhen Key Laboratory of mountain hazards and earth surfaceprocesses ChineseAcademy of Sciences Chengdu 610041 China Graduate University of chineseacademy of {2. Beijing I ooo49 China institute of mountain {2. and environment 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 2. in depth and 1m 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

Scattered Rural Settlements and Development of mountainous Regions in Western sichuan,{2.

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Wuhan University Journal of Natural sciences 2007年第4期12卷 737-742页

作者： GAO Yanjun CHEN Guojie SHEN Maoying Key Laboratory of mountain hazards and Surface Process Chinese Academy of Sciences/Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 Sichuan China Graduate University of chinese academy of sciences Beijing 100049 China sichuan academy of Social {2. Chengdu 610072 Sichuan China

Making rural settlements of mountainous Regions in Western sichuan as the study objects and using symbolic statistical methods, then combining the case study of Daofu County, the paper analyzes the negative impact of the scattered rural settlements on infrastructure construction, farmers＇ income increase and mountain ecological reconstruction in mountainous regions of western sichuan. The results indicate that economic density is positively related to both rural settlements density （R^2.0.73） and rural population density （R^2.0.77）, and it is the same for relationship between towns density and rural settlements density （R^2.0.88） and between towns density and economic density （R^2.0.71）, and the scattered distribution pattern of the rural settlements and shortage of economic centers is a major factor to the lagged socioeconomic development. On the eco-economic zoning to Daofu County, the paper indicates the spatial distribution model and the industrial development model of the rural settlements need to be changed, and rural population should be concentrated in larger rural settlements with development of off-farm industries while infrastructure construction is to reinforced.

关键词： mountainous regions in western sichuan rural settlement scattered distribution development

Failure Mechanisms of Post-Earthquake Bedrock Landslides in Response to Rainfall Infiltration

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Journal of mountain Science 2011年第1期8卷 96-102页

作者： WU Yong HE Siming LUO Yu LI Xinpo Key laboratory of mountain hazards and Earth Surface Process Chinese Aeademy of Sciences Chengdu 610041 China institute of mountain {2. and environment Chinese Academy of Sciences Chengdu 610041 China

Among the triggering factors of postearthquake bedrock landslides, rainfall plays an important role. However, with slope variation, the mechanism of its effects on the failure of rock landslides is not dear. Here, from the viewpoint of fracture mechanics, and based on post-earthquake conditions, the mechanisms of crack propagation, water infiltration and development of the sliding surface were investigated. Then, according to the upper boundary theorem, the effects of water infiltrated into fractures on the stability of rock slopes were analyzed quantitatively. Finally, an example is presented to verify the theory. The results show that the propagation and coalescence of cracks and the lubrication of incipient sliding surfaces are the main causes of the failure of post-earthquake rock landslides in response to rainfall.

关键词： Post-earthquake Fracture infiltration Fracture mechanics Propagation and coalescence Upper boundary theorem Energy theory Rock landslide

Site-specific Vulnerability Assessment for Debris Flows: Two Case Studies

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Journal of mountain Science 2006年第1期3卷 20-27页

作者： Liu Xilin institute of mountain {2. and environment Chinese Academy of Sciences Chengdu Sichuan 610041 China

Here the vulnerability is defined as the potential total maximum losses due to a debris flow damaging event for a specific debris flow fan. The vulnerability is classified into property vulnerability and population vulnerability. Assessment indexes include the assets of buildings, traffic facilities, lifeline works, personal properties, and land resources for property vulnerability; age, education, and wealth of the inhabitants, natural population growth rate, and population density for population vulnerability. The vulnerability is expressed as the sum of the transformed values of the losses of property and population. Two study cases with post-fact damages by historic debris flow events in sichuan of SW china are presented.

关键词： Vulnerability to debris flow vulnerability factors case study china