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Analysis on the Dynamical Process of Donghekou Rockslide-Debris Flow Triggered by 5.12.Wenchuan Earthquake

Journal of Mountain Science 2011年第2期8卷 140-148页

作者： SUN Ping ZHANG Yongshuang SHI Jusong CHEN Liwei Key Laboratory of Neotectonic Movement & Geohazard Ministry of Land and Resources Beijing China Institute of Geomechanics Chinese Academy of Geological Sciences Beijing China china Nuclear Power Engineering Corporation Ltd. Beijing China

Among the geo-hazards caused by the great Wenchuan Earthquake, the rapid and long runout rockslide-debris flow is of primary concern due to the large volume of displaced material and the resultant catastrophic impacts to the landscape and socioeconomic structure. In order to analyze the dynamical process of this kind of geo-hazard, the Donghekou rockslide-debris flow is given as an example in this paper. This event, which killed 780 people, initiated at an elevation of 13.0 m with a total long run-out distance of more than 2.00 m. The slide mass is mainly composed of dolomite limestone and siliceous limestone of Sinian system, together with carbon slate and phyllite of Cambrian. During the processes from slide initiation to the final cessation of slide movement, five dynamic stages took place, here identified as the initiation stage, the acceleration of movement stage, the air-blast effect stage, the impact and redirection stage and the long runout slidematerial accumulation stage. Field investigations indicate that due to the effects of the earthquake, the dynamics of the Donghekou rockslide-debris flow are apparently controlled by geologic and tectonic conditions, the local geomorphological aspects of the terrain, and the microstructural and macroscopic mechanical properties of rocks which compose the slide mass. These three main factors which dictate the Donghekou rockslide-debris flow dynamics are discussed in detail in this paper, and significant results of field investigations and tests of materials are presented. The above dynamical processes are analyzed in this paper, and some useful conclusions have been gained.

关键词： Dynamical process Donghekou Rockslide-debris flow Wenchuan earthquake

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Soil Erosion Control Degree of the Project of Converting Farmland to Forest in Mountainous Areas at china's Southwest Border:A Case Study in Mangshi,Yunnan Province

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Journal of Mountain Science 2011年第6期8卷 845-854页

作者： YANG Zisheng HAN Huali ZHAO Qiaogui Institute of land ＆ resources and Sustainable Development Yunnan University of Finance and Economics Kunming 650221 China Southwest University Chongqing 400715 China Department of land ＆ resources of Yunnan Province Kunming 650224 China

There have been few in-depth quantitative studies on soil erosion control and the ecological effects of land use changes. Soil erosion is the first eco-environmental problem particularly in mountainous areas. A major problem in the conversion of farmland to forest is to control soil erosion and improve ecological environment and thus to improve land use sustainability. We report results of calculation and analysis on soil erosion from converted farmland parcels in city of Mangshi （near the SW frontier of china） and the surrounding areas before and after the nine-year （2.00-2.09） project of converting farmland to forest. There was increased water conservation effect, as a result of decreased soil erosion. The average erosion modulus of the farmland returning to eco-friendly uses decreased by 5,53..59 t/km2.a and the control degree of soil erosion modulus reached 71.00%. The increased soil erosion after the returning in the typical sample area ＂did not drop, but increased＂ as the terraced fields decreased but sloping farmland inereased and yet woodland decreased.

关键词： Soil erosion Control degree The projectof converting farmland to forest Converted farmland

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Validity of the Bouchet's complementary relationship at 102.observatories across china

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Science china Earth Sciences 2009年第5期52卷 708-713页

作者： YU JingJie1,2.ZHANG YongQiang3.LIU ChangMing1,2.1 Institute of Geographic Sciences and Natural resources Research,Chinese Academy of Sciences,Beijing 100101,{3. 2.Key Laboratory of Water Cycle and Related {2. Surface Processes,Chinese Academy of Sciences,Beijing 100101,{3. 3.CSIRO {2. and Water,PO Box 1666,Canberra ACT 2.01,Australia Institute of Geographic Sciences and Natural resources Research Chinese Academy of Sciences Beijing 100101 China Key Laboratory of Water Cycle and Related land Surface Processes Chinese Academy of Sciences Beijing 100101 China CSIRO La

Bouchet in 1963.hypothesized that for large homogeneous land surface with minimum advection of heat and moisture,there exists a 1:1 complementary relationship of potential and actual evaporation coupled through land-atmosphere *** complementary relationship has been widely used to estimate regional actual evaporation and explain the pan evaporation *** examine the standardized potential evaporation(potential evaporation divided by wet environment evaporation) at 102.observatories at different elevations across ***,the relationship is appropriate at the low elevations(<1000 m).With the increase of elevation,vapor transfer power becomes much less than radiation energy budget because of lower vapor pressure deficit and stronger global solar *** a result,at the high elevations(over 1000 m),the excess energy resulted by limited moisture availability is not enough to be converted into drying power of the *** result suggests that the complementary relationship is asymmetric at the high elevations.

关键词： evaporation complementary relationship elevation china

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Differential Hydrological Grey Model (DHGM) with self-memory function and its application to flood forecasting

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Science china(Technological Sciences) 2009年第4期52卷 1039-1049页

作者： CHEN XiangDong1, XIA Jun1,2.& XU Qian3.1 Key Laboratory of Water Cycle and Related land Surface Processes, Institute of Geographic Sciences and Natural resources Research, Chinese Academy of Sciences, Beijing 100101, {2. 2.State Key Laboratory of Water resources and Hydropower Engineering Science, Wuhan University, Wuhan 43.072. {2. 3.School of Hydrology and Water resources, Hohai University, Nanjing 2.0098, {2. 1. Key Laboratory of Water Cycle and Related land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China 2. State Key Laboratory of Water resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China 3. School of Hydrology and Water resources Hohai University Nanjing 210098 China

This paper addresses a problem of flood forecasting with the self-memory function. Considering flood forecasting’s uncertainty and updating demand, a hybrid hydrological model, namely Differential Hy- drological Grey Model with self-memory function (DHGM-SM), is developed. The model has two fold features. One is to establish a self-memorization equation linked with DHGM, that could extract useful information from past data series and realize updating of hydrological dynamic process. The other is that this model has higher efficiency relative to original hydrological model without self-memory func- tion. This approach was applied to river flow forecasting of two representative basins in Tunxi of South china and Daqinggou of North china. It is shown that this hybrid method has satisfactory forecasting accuracy by examination of both calibration and validation.

关键词： differential grey model the self-memorization principle real-time forecasting faded-memory recursive least square method

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The impact of vegetation restoration on erosion-induced sediment yield in the middle Yellow River and management prospect

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Science china Earth Sciences 2005年第6期48卷 724-741页

作者： CHEN Hao1, ZHOU Jinxing2. CAI Qiangguo1, YUE Zhongqi3. LU Zhongchen4, LIANG Guanglin1& HUANG Jianguo5 1. Key Laboratory of Water Cycle and Related land Surface Processes, Institute of Geographic Sciences and Natural resources Re-search, Chinese Academy of Sciences, Beijing 100101, {2. 2. Institute of Forestry, Chinese Academy of Forestry Sciences, Beijing 100091, {2. 3. Department of Civil Engineering, University of Hong Kong, Hong Kong, {2. 4. Eco-environmental Research Center, Chinese Academy of Sciences, Beijing 100085, {2. 5. College of resources and Environment, Southwest Agricultural University, Chongqing 400716, {2. Correspondence should be addressed to Chen Hao 1. Key Laboratory of Water Cycle and Related land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. Institute of Forestry Chinese Academy of Forestry Sciences 100091 Beijing China 3. Department of Civil Engineering University of Hong Kong Hong Kong China 4. Eco-environmental Research Center Chinese Academy of Sciences 100085 Beijing China 5. College of resources and Environment Southwest Agricultural University 400716 Chongqing China

According to the characteristics of water and erosion environments of different natural zones on the Loess Plateau, this paper studies changes of vegetation types, distribution boundaries of forest and grass as well as restoration capacity of vegetation in different natural zones in the middle Yellow River. The annual precipitation of 53. mm is the critical annual pre-cipitation for forest and grass distribution in the middle Yellow River. Among the zonal and azonal environmental factors affecting watershed sediment yield, the intermediate diameter D50 (mm) of suspended load and forest coverage (V, %) play the leading role. Of them the effect weight of forest coverage (V, %) on catchments sediment yield is only 3.4% less than the role of the intermediate diameter (D50, mm), they are almost the same. To effectively control soil erosion in semiarid, especially in hilly-gullied areas and make sediment transport modulus reduce to less than 6000 t/km2. it is rather difficult by merely relying on natural restoration of forest. In the process of cultivated land conversion into forest land and grassland, measures suiting local conditions should be adopted in tree species selection and artificial afforestation (grass planting) based on management with biological measures for slopeland and engineering measures for hilly-gullied areas, so that watershed forest coverage in key counties can reach at least over 3.%.Compared with the standard period of precipitation prior to the 1960s, with the decrease of an-nual precipitation at various periods, plant productivities decline to different degrees under natural conditions. The main reason accountable for the low survival rate of new seedlings and grass over years is due to precipitation decrease. In light with regression models of annual pre-cipitation and natural vegetation productivities, it is possible to obtain estimated values of wa-tershed natural vegetation productivity and eco-water consumption needed for the restoration to

关键词： vegetation restoration, eco-water requirement, watershed sediment yield, the middle Yellow River.

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Aridity/humidity status of land surface in china during the last three decades

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Science china Earth Sciences 2005年第9期48卷 1510-1518页

作者： WU Shaohong1, YIN Yunhe1,2. ZHENG Du1 & YANG Qinye1 1. Institute of Geographical Sciences and Natural resources Research, Chinese Academy of Sciences (CAS), Beijing 100101, china 2. Graduate School of the CAS, Beijing 10003., china 1. Institute of Geographical Sciences and Natural resources Research Chinese Academy of Sciences (CAS) 100101 Beijing China 2. Graduate School of the CAS 100039 Beijing China

To clarify aridity/humidity status of land surface is helpful for studying environmental background and regional differences, seeking causes of environmental change, and providing a scientific basis for researches on climate change in the future. In this paper, the authors calcu- lated potential evapotranspiration of china using data from 616 meteorological stations during the period of 1971―2.00 with the Penman-Monteith model recommanded by FAO in 1998. Vy- sothkii’s model was used to calculate aridity/humidity index. Then the calculated results of sta- tions were interpolated to land surface using ArcGIS. Results show that the annual average po- tential evapotranspiration is 400―1500 mm in the whole country, 600―800 mm in most parts of it; and 3.0―1400 mm in growing season (April―Octobor), which is nearly 2.0 mm less than the annual average. According to the aridity/humidity indexes of 1.0, 1.5 and 4.0, the aridity/humidity status is categorized to four types, namely, humid, subhumid, semiarid and arid. A majority of stations (76%) are more humid in growing season than the annual average. Results of com- prisons between the distribution map of aridity/humidity index with that of precipitation and vegetation indicate a good consistence of aridity/humidity status with natural environment. Therefore potential evapotranspiration calculated with modified FAO’s Penman-Monteith model in combination with aridity/humidity index that considers water balance can more reasonably explain the actual land surface aridity/humidity status of china.

关键词： potential evapotranspiration, aridity/humidity status, land surface, regional differences, Penman-Monteith.

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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, china 2.College of {3. and Environmental Science, Chongqing University, Chongqing 400044, china 3.College of {3. Science & Technology, Beijing Normal University, Beijing 100875, china 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

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An Overview on Wavelet Software Packages

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Wuhan University Journal of Natural Sciences 2001年第Z1期6卷 593-600页

作者： Fan Qi\|bin 1, Li Hong 2.1. School of Mathematics and Statistics, Wuhan University, Wuhan 43.072. china 2. School of Electronic information, Wuhan University, Wuhan 43.072. china School of Mathematics and Statistics Wuhan University Wuhan China School of Electronic information Wuhan University Wuhan China

Wavelet analysis provides very powerful problem\|solving tools for analyzing, encoding, compressing, reconstructing, and modeling signals and images. The amount of wavelets\|related software has been constantly multiplying. Many wavelet analysis tools are widely available. This overview represents a significant survey for many currently available packages. It will be of great benefit to engineers and researchers for using the toolkits and developing new software. The beginner to learning wavelets can also get a great help from the review. If you browse around at some of the Internet sites listed in the reference of this paper, you may find more plentiful wavelet resources.

关键词： wavelet transforms image compression matching pursuit lifting MATLAB

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Risk analysis system of geo-hazard based on GIS technique

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Journal of Geographical Sciences 2002年第3期12卷 371-376页

作者： ZHU Liangfeng, ZHANG Guirong, YIN Kunlong, ZHANG Liang (1. Faculty of Engineering, china University of Geosciences, Wuhan 43.074, china 2. china Research Institute of land resources and Economy, Beijing 101149, china) Faculty of Engineering China University of Geosciences(Wuhan) Wuhan 430074 china Research Institute of land {2. and Economy 北京 101149

The socio-economic attribute of geo-hazard made us distinguish it from the traditional engineering geology study. It will get more social benefit from the analysis of the geo-hazard in the socio-economic attribute. The hazard and the vulnerability of the element controls the risk level of the regional geo-hazard. The risk analysis supported by GIS in geo-hazard study is one of the most important directions. Based on the author’s studies in recent years, a risk analysis system of regional geo-hazard (RiskAnly) has been developed on the basis of software MAPGIS. The paper introduces the train of system design, the structure and the workflow of RiskAnly. As a case study, the paper also deals with the risk zonation of the regional landslide hazard of china.

关键词： geo-hazard GIS risk analysis landslide

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Paleomagnetic study on orogenic belt:An example from Early Cretaceous volcanic rocks,Inner Mongolia,china

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Science china Earth Sciences 2004年第12期47卷 1127-1133页

作者： REN Shoumai 1,2.,ZHU Rixiang 1 ,HUANG Baochun 1 ,ZHANG Fuqin 1 & WANG Hongqiang 1 1.Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 10002.,china 2.Strategic Research Center for Oil and Natural Gas,The ministry of {2. and resources of china,Beijing 10003.,china 1. Strategic Research Center for Oil and Natural Gas The Ministry of Land and Resources of China 100034 Beijing China 2. Chinese Academy of Sciences Institute of Geology and Geophysics 100029 Beijing China

We report paleomagnetic results for Early Cretaceous lava flows collected from the Suhongtu area of Inner Mongolia, the middle part of the Tianshan-Mongolia Fold Belt (TMFB). Rock-magnetic experiments for different lava flows indicate that the main magnetic mineral is pseudo-single-domain (PSD) magnetite. The characteristic high-temperature remanence com- ponent is isolated by thermal demagnetization temperature steps between 3.0°C and 585"C, which yields a mean direction of D = 2..6°, I=56.0° with α 95 = 2.3.. We interpret this high-temperature remanence component as primary magnetization based mainly upon the petrographic analysis, which shows that the shape of magnetite crystal is relatively rounded square or polygon without internal reflection and deuterogenous phenomenon. The correspond- ing pole of the high-temperature remanence component is at 71.1°N, 2.0.5°E with A 95 = 2.7°. This Early Cretaceous pole is in good agreement with those for Siberia, North china, and Inner Mongolia, suggesting that these continental blocks had already sutured together in the Early Cretaceous, which would further provide constraints on better understanding of the formation and evolution of the TMFB.

关键词： orogenic belt, paleomagnetism, Suhongtu of Inner Mongolia, Eurasia.

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