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Planation Surfaces on the Tibet Plateau,china

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Journal of mountain Science 2008年第4期5卷 310-317页

作者： zhang Xinbao HE Xiubin WANG Yangchun LONG Yi institute of {1. {2. and environment CAS Chengdu 610041 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment GAS Xi＇an 710075 China Graduate University of the Chinese Academic of Sciences Beijing 100039 China

A planation hypothesis is proposed to explain landform evolution of the Tibet Plateau. A denudation threshold （T）, the maximum potential denudation rate for a certain type of rock, is introduced to explain the combined effects of lithology and tectonics on landform evolution. If the tectonic uplifting rate （U） is equal to or less than the threshold rate （U ≤ T）, the tectonic uplifting and terrain denudation are in dynamic equilibrium, and landforms are in a steady state. The end product should be planation surfaces whether the original landforms are flat plains or deeply dissected mountains. If U 〉 T, uplift and denudation are not able to reach a dynamic equilibrium state. The plateau surface is mostly underlain by soft rocks, such as the Mesozoic epimetamorphic argillites and Tertiary sedimentary rocks, while the mountain ranges comprise hard rocks, such as granite, gneiss and limestone. In soft rock regions, hills are low with a relative relief of mostly less than {2.0 m and the slopes are gentle at a gradient of 〈2.0. In contrast, hills can maintain steep slopes in hard rock regions. The Tibet Plateau has been under an equilibrium condition between tectonic uplifting and denudation except for the mountain ranges. The plateau might have reached the present altitudes before the Quaternary.

关键词： planation denudation threshold landform evolution Tibet Plateau china

Soil Microbial Population Dynamics along a Chronosequence of Moist Evergreen Broad-leaved Forest Succession in Southwestern china

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Journal of mountain Science 2010年第4期7卷 327-338页

作者： ZHU Wanze CAI Xiaohu LIU Xingliang WANG Jinxi CHENG Song zhang Xiuyan LI Dengyu LI Maihe institute of {1. {2. and environment Chinese Academy of Sciences Chengdu 610041 China sichuan {1. of Forestry Chengdu 610081 China Siehuan Agricultural University Yaan 625014 China Swiss Federal Research institute WSL Zuereherstrasse 111 CH-8903 Birrnensdorf Switzerland

Little is known about whether soil microbial population dynamics are correlated with forest *** test the hypotheses that(1. soil microbial composition changes over successional stages,and(2. soil microbial diversity is positively correlated with plant species diversity,we determined the soil microbial populations,community composition,and microflora diversity in evergreen broad-leaved forests along a chronosequence of vegetation succession from 5 to 300 years in southwestern *** soil microbial community was mainly composed of bacteria(87.1.98.7% of the total microorganisms and 1. genera identified),fungi(0.3-4.0%,7 genera),and actinomycetes(2.1.9.1.,8 species and 1.genus).There were significant differences in soil microbial populations among different successional stages and within the four *** seasonal variations of the soil microbial community may be associated with the seasonal changes in environmental *** changes in soil microbial diversity(Shannon-Wiener index) with successional time followed one-humped,convex curves peaked at-1.0 years since restoration,which is identical with the trends of the aboveground plant *** plant diversity resulting in enhanced nutrient flow and root exudation may contribute to positive relationships between the soil microbial diversity and plant ***,decreases in soil microbial diversity in the late-successional stages appear to be related to the net loss in species richness that occurs after 1.0 years since *** findings confirm the intermediate disturbance hypothesis that suggests diversity peaks at midsuccessional stages.

关键词： Actinomycetes Bacteria Fungi Microbial diversity Moist evergreen broad-leavedforest Seasonal dynamics

A Remote Sensing-based Analysis on the Impact of Wenchuan Earthquake on the Core Value of World Nature Heritage sichuan Giant Panda Sanctuary

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Journal of mountain Science 2011年第3期8卷 458-465页

作者： YU Hu ZHAO Yongtao MA Yuewei SUN Yulian zhang Hu YANG Shihong LUO Yong institute of {1. {2. and environment ChineseAcademy of Sciences No. 9. Section 4. South Renmin Road China Graduate University of Chinese academy of Sciences Beijing 100049 China sichuan World Heritage Administrative Office

In this study,we used remotely sensed data,GIS modeling,and statistical methods to evaluate the damage caused by the Wenchuan Earthquake (May 1.,2.08) to the giant panda (Ailuropoda melanoleuca) habitat in the World Nature Heritage sichuan Giant Panda Sanctuary (WHSGPS) in{1..A landscape ecological analysis found increases of landscape heterogeneity,complexity,and fragmentation in the giant panda habitat after the earthquake.A terrain analysis found that slope and elevation are directly associated with the distribution of the damaged *** slope and elevation increase,the size of the damaged area keeps increase until to a peak,and then starts to *** total area of the damaged vegetation in our study area is 1.4.2. km 2.accounting for 3.78% of the study area;30.46% of that 1.4.2. km 2.is located in the Core Zone of *** are 1..57km 2.of the damaged vegetation located in the identified suitable giant panda habitat,accounting for 1.75% of the total area of suitable giant panda habitats in the study *** on these findings,we conclude that the Wenchuan Earthquake does not have significant impact on the WHSGPS as a whole.

关键词： World Nature Heritage Giant Panda Sanetuaries Suitable giant panda habitat Model Wenehuan Earthquake Landscape pattern GIS RS

^(1.7)Cs Redistribution in Thin Stony Soil of a Carbonate Rock Slope in Southwest china

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Pedosphere 2011年第1期21卷 37-45页

作者： LI Hao zhang Xin-Bao WANG Kc-Lin WEN An-Bang institute of {1. {2. and environment Chinese Academy of Sciences Chengdu 610041 (China) Graduate University Chinese Academy of Sciences Beijing 100049 (China) State Key Laboratory of environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 (China) institute of Subtropical Agriculture Chinese Academy of Sciences Changsha 410125 (China)

The fallout radionuclide cesium-1.7(1.7 Cs) has been widely employed as a tracer for assessment of soil loss from thick uniform soils;however,few studies have been conducted on thin stony soils on slopes underlain by carbonate rocks which are widely distributed in karst *** derived from 1.7 Cs measurement of soil samples collected along a carbonate rock slope with thin stony soil where neither soil erosion nor deposition occurred was used to investigate the characteristics of 1.7 Cs redistribution in a karst area of Southwest *** results indicated that the 1.7 Cs inventories of the surface soil on the slope studied were much lower than that of the local 1.7 Cs reference inventory and the 1.7 Cs activities were much higher than those on slopes with thick uniform *** spatial distribution of 1.7 Cs inventories was characterized by considerable *** high 1.7 Cs depletion in the stony soil of the slope studied was mainly because a considerable proportion of the fallout input of 1.7 Cs could be lost with runoff and the dissolution of carbonate particles in the soil promoted the loss of 1.7 *** demonstrated that the rates of soil loss could not be estimated from the degree of depletion of the 1.7 Cs inventory relative to the local reference inventory for the thin stony soil of the rocky slope underlain by carbonate rocks in the study area in the way that has been widely used in areas with thick uniform soils.

关键词： carbonate dissolution, ^1.7Cs fallout, ^1.7Cs inventory karst area runoff

Effects of Terracing and Agroforestry on Soil and Water Loss in Hilly Areas of the sichuan Basin,{1.

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Journal of mountain Science 2008年第3期5卷 241-248页

作者： J.H. zhang Z.A. SU G.C. LIU Key Laboratory of mountain {1. and Earth Surface Processes Chinese Academy of Sciences 610041 China institute of {1. {2. and environment Chinese Academy of Sciences ＆Ministry of Water Conservancy Chengdu 610041 China The Graduate School of the Chinese academy of Sciences Beijing 100049 China

Soil erosion in hilly areas of the sichuan Basin is a serious concern over sustainable crop production and sound ecosystem. A 3-year experiment was conducted using the method of runoff plots to examine the effects of terracing and agroforestry in farmland systems on soil and water conservation of slope fields in the hilly areas in Jianyang County, sichuan Province, Southwestern{2.. A power function (Y = aXb) can statistically describe the relationship between water runoff (Y) and rainfall (X). The regression equation for the treatment of sloping terraces with crops (Plot 2. is remarkably different from that for the treatment of sloping terraces with grasses and trees (Plot 1. and the conventional up- and down-slope crop system (Plot 3) regarding equation coefficients, while regression equations are similar between Plot 1.and Plot 3. Water runoff amount and runoff coefficient of slope fields increased by 2.3}5～41.0 % and 2..5～69.7 % respectively, compared to those of sloping terraces, suggesting that terracing notably reduced the water runoff in the field. In the case of sloping terraces, lower amount of water runoff was observed on sloping terraces with crops than on sloping terraces with grasses and trees. Sediment yields on the slope fields in the normal year of rainfall distribution were notably higher (34.41.331.67 % and 37.06～403.44 % for Plot 1.and Plot 2. respectively) than those on sloping terraces, implying that terracing also plays a significant role in the reduction in soil erosion. It is suggested that terracing with crops is significantly effective for soil and water conservation in cultivatedfarmland, while the conventional practice of up- and down- slope cultivation creates high rates of water runoff and soil sediment transport. Terracing with grasses and fruit trees shows a less reduction in water runoff than terracing with crops, which was observed in the 3-year experiments.

关键词： Agroforestry sediment transport runoff sloping terrace soil and water conservation

Rural Public Investment and Benefit in sichuan's Hilly and {1.ous Areas

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Asian Agricultural Research 2012年第8期4卷 28-32页

作者： zhang Hai-qin 1.3 ,LIU Shao-quan 1.,LUO Ren-fu 2.,zhang Lin-xiu 2.1. institute of mountain hazards and environment,Chinese academy of Sciences,chengdu 61.041.{12. 2. institute of Geographic Sciences and Natural Resources Research,Chinese academy of Sciences,Beijing 1.01.1.{12. 3. Graduate University of Chinese academy of Sciences,Beijing 1.0049,{12.

Using representative sampling survey data,we take the case of roads,domestic water,irrigation facilities,clinics and schools,to give an overview of the status quo of rural public investment in sichuan's hilly and {1.ous areas in the period 2.05 -2.08; conduct comprehensive analysis of public investment benefit,from the status quo of supply and demand,social benefit and villagers' satisfaction. The results show that the social benefit arising from the construction of road projects is good,while the social benefit arising from the construction of irrigation facilities is poor; the matching effect of supply and demand of public investment is poor,especially for the investment in irrigation facilities; on the whole,villagers' satisfaction with public investment has been promoted,but most of the villagers are still unsatisfied with the current irrigation facilities. The major capital source of rural public investment is from the government,but from the perspective of the villagers' demand,we should further increase the public financial input.

关键词： Rural public investment Social benefit index Evalu

Two-dimensional Numerical Model for Debris Flows in the Jiangjia Gully,Yunnan Province

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Journal of mountain Science 2011年第6期8卷 757-766页

作者： PENG Hong ZHAO Yanxin CUI Peng zhang Wanshun CHEN Xuejiao CHEN Xiaoqing College of Water Resources and Hydropower Engineering Wuhan University Wuhan 430072 China School of Resource and environmental Science Wuhan University Wuhan 43o079 China institute of {1. {2. and environment Chinese Academy of Sciences Chengdu 610041 China

Debris flows are recurrent natural hazards in many {1.ous *** paper presents a numerical study on the propagation of debris flows in natural erodible open channels,in which the bed erosion and sedimentation processes are *** on the Bingham fluid theory,a mathematical model of the two-dimensional non-constant debris flow is *** governing equations include the continuity and momentum conservation equations of debris flow,the sediment convection-diffusion equation,the bed erosion-deposition equation and the bed-sediment size gradation adjustment *** yield stress and shear stress components are included to describe the dynamic rheological *** upwind control-volume Finite Volume Method (FVM) is applied to discretize the convection *** improved SIMPLE algorithm with velocity-free-surface coupled correction is developed to solve the equations on non-orthogonal,quadrilateral *** model is applied to simulate a debris flow event in Jiangjia Gully,Yunnan Province and to predict the flow pattern and bed erosion-deposition *** results show the effectiveness of the proposed numercial model in debris flow simulation and potential hazard analysis.

关键词： Debris flow Numerical simulation SIMPLE algorithm Finite Volume Method Hazardanalysis Jiangjia Gully

A New Treatment of Depression for Drainage Network Extraction Based on DEM

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Journal of mountain Science 2009年第4期6卷 311-319页

作者： WANG Yan PENG Hong CUI Peng zhang Wanshun QIAO Fei CHEN Cai'er School of Resource and environmental Science Wuhan University Wuhan 430079 China College of Water Resources and Hydropower Engineering Wuhan University Wuhan 430072 China institute of {1. {2. and environment Chinese Academy of Sciences Chengdu 610041 China Chinese academy of {1.al Sciences Beijing 100012 China

Depressions in landscapes function as buffers for water and sediment. A landscape with depressions has less runoff, less erosion and more sedimentation than that without depressions. Sinks in digital elevation models （DEMs） can be considered the real features that represent depressions in actual landscapes or spurious features that result from errors in DEM creation. In many hydrological and erosion models, all sinks are considered as spurious features and, as a result, these models do not deal with the sinks that represent real depressions. Consequently, the surface runoff and erosion are overestimated due to removing the depressions. Aiming at this problem, this paper presents a new method, which deal with the sinks that represent real depressions. The drainage network is extracted without changing the original DEM. The method includes four steps： detecting pits, detecting depressions, merging depressions, and extracting drainage network. Because the elevations of grid cells are not changed, the method can also avoid producing new fiat areas, which are always produced by the conventional filling methods. The proposed method was applied to the Xihanshui River basin, the upper reach of the Jialingjiang River basin, china, to automatically extract the drainage network based on DEM. The extracted drainage network agrees well with the reality and can be used for further hydrologic analysis and erosion estimation.

关键词： Drainage network extraction Depression processing Digital elevation model Wooden barrel effect Xihanshui River basin.

Community Structure and Seasonal Variation of Soil Arthropods in the Forest-Steppe Ecotone of the mountainous Region in Northern Hebei,{1.

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Journal of mountain Science 2010年第2期7卷 187-196页

作者： ZHU Xinyu GAO Baojia yuan Shengliang HU Yunchuan institute of {1. {2. and environment CAS Chengdu 610041 China Graduate University of the Chinese academy of Sciences Beijing 100039 China Hebei North University Zhangjiakou 075000 China Agricultural University ofHebei Baoding 071000 China

Soil fauna have been receiving more and more attention because they play an important role in nutrient ***,there is a lack of information on soil arthropods in the forest-steppe ecotone in the mountainous region of northern Hebei,which makes it difficult to meet the need of protecting biodiversity in this *** arthropod communities were investigated in the forest-steppe ecotone in northern Hebei province to provide basic information on changes in mountain soil fertility,which could promote the development of soil arthropod communities in mountain *** the preliminary identification,a total of 7994 individual soil arthropods were collected,which belonged to 2. groups,6 classes and 2. ***,Hymenoptera and Collembola were the dominant groups in the *** number of Acarina was higher than Collembola,and this phenomenon was obviously different from other areas in the same climate *** increased abundance of rare groups in the Forest zone with the richer vegetation,higher arthropod abundance and more substantial litter depth,could be interpreted as a reaction to the suitable soil environment and food *** these rare groups were sensitive to environmental changes,which could be regarded as biotic indicators for evaluating soil *** analysis of community diversity showed that the abundance index (d),the Shannon-Wiener index (H'),the evenness index (J) and the density-group index (DG) were significantly higher in the forest zone,lower in the forest-steppe zone,and lowest in the meadow-steppe *** variations in community composition correlated with changes in average air temperature and precipitation in this *** and individuals of soil arthropod communities in the three zones were present in greater numbers in the middle of the rainy season than in the early or late periods of the rainy season as a *** the same time,seasonal changes in soil arthropod communities from different plots were also

关键词： Soil arthropods Diversity Composition Ecotone Seasonal change