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Remote Sensing Monitoring of the Subalpine Coniferous Forests and Quantitative Analysis of the Characteristics of Succession in East Mountain Area of Tibetan Plateau——A Case Study With Zamtang County 被引量:5
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作者 张学儒 张镱锂 +2 位作者 刘林山 张继平 高俊刚 《Agricultural Science & Technology》 CAS 2011年第6期926-930,共5页
The study area lies in the Dadu River drainage area in upstream Yangtze River.The spatial distribution of subalpine coniferous forests in 1989 and 2009 was extracted by means of a combined method of object orientation... The study area lies in the Dadu River drainage area in upstream Yangtze River.The spatial distribution of subalpine coniferous forests in 1989 and 2009 was extracted by means of a combined method of object orientation and visual interpretation,and then the overlaying analysis of these data was conducted.The type and spatial location of succession were discovered and served as the sample of dependant variable.Meanwhile,supported by GIS technology and based on DEM and thematic data,the eight variables including altitude,slope,sin and cosin of aspect,curvity of land surface,and distance to residential area,cultivated land and road were extracted served as the sample of spatial succession of subalpine coniferous forests to fit Logistic Regression,and then the contribution of each independent variable as well as the spatial property of the occurrence probability of succession was calculated.The results suggested that,during the succession of subalpine coniferous forests to meadow,the closer to the residential area and cultivated land,the greater the contribution to succession is.In particular,when the distance to the residential area decreases by one unit,the probability for its conversion to meadow will be increased by 1.15 times.During the succession of subalpine coniferous forests to deciduous-broadleaved shrubs,the sin of aspect and distance to residential area contribute more,and the probability of succession increases with increasing degree of northwardness,i.e.when the degree of northwardness increases by one unit,the probability will be increased by 1.2 times.The quantitative analysis of spatial succession property of subalpine coniferous forests will supply scientific basis to the protection and restoration of subalpine coniferous forests. 展开更多
关键词 Subalpine Coniferous Forests Logistic Regression GIS East Mountain area of tibetan Plateau
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The Current Status of Trilingual Education in Tibetan Areas of China
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作者 代春 《海外英语》 2014年第12X期79-82,84,共5页
In China trilingual education, as an important part of Chinese national education, is likely to be not only required, but essential. However, among the tremendous achievements, there still exist some problems, such as... In China trilingual education, as an important part of Chinese national education, is likely to be not only required, but essential. However, among the tremendous achievements, there still exist some problems, such as different standard in educational management and requirements, insufficiency of trilingual teachers and unreasonableness in teacher structure, shortage both in the number and characteristics of trilingual teaching materials, lateness in the study on TETAC and insufficiency of study result, and backwardness in teaching approaches and methods, etc. 展开更多
关键词 trilingual EDUCATION tibetan areas CURRENT STATUS
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Land Remediation Projects in Poverty-stricken Counties in Tibetan Areas Promoting Poverty Alleviation——A Case Study of Songpan County,Sichuan Province 被引量:2
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作者 Feng QIU Zisheng YANG 《Asian Agricultural Research》 2019年第3期55-58,61,共5页
Songpan County is a poverty-stricken county in the four provinces of China,one of the concentrated areas in China. This paper analyzes the effectiveness of land consolidation in Songpan County to promote poverty allev... Songpan County is a poverty-stricken county in the four provinces of China,one of the concentrated areas in China. This paper analyzes the effectiveness of land consolidation in Songpan County to promote poverty alleviation and development through specific cases. The results show that land remediation has improved agricultural production conditions,promoted agricultural efficiency,increased farmers' income,improved rural living conditions,promoted the development of urban and rural integration,improved the ecological environment,solved the problem that restricts the survival and development of poverty-stricken areas,enhanced the ability of farmers to develop themselves,raised the level of civilization in rural areas,and promoted poverty alleviation and development. The poverty alleviation and development has provided certain financial support for land remediation. It has promoted land remediation,and pointed out key directions for land remediation. It has an indirect promotion effect on land remediation. 展开更多
关键词 LAND REMEDIATION POVERTY alleviation POVERTY-STRICKEN areas tibetan areas Songpan County
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Morphological Characteristics of Precipitation Areas over the Tibetan Plateau Measured by TRMM PR 被引量:2
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作者 Yilun CHEN Aoqi ZHANG +2 位作者 Yunfei FU Shumin CHEN Weibiao LI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第4期677-689,共13页
The multidimensional morphological characteristics(including scale, horizontal shape and 3 D morphology) of precipitation areas over the Tibetan Plateau in summer were studied using 15 years(1998–2012) of observation... The multidimensional morphological characteristics(including scale, horizontal shape and 3 D morphology) of precipitation areas over the Tibetan Plateau in summer were studied using 15 years(1998–2012) of observational data from the precipitation radar onboard the Tropical Rainfall Measuring Mission satellite. As the scale of the precipitation area increased from 20 to 150 km, the near-surface rain rate(RRav) of the precipitation area increased by up to 78%(from ~1.12 to ~2 mm h~(-1)). Linear precipitation areas had the lowest median RRav(~1 mm h~(-1) over the eastern Tibetan Plateau),whereas square-shaped precipitation areas had the highest median RRav(~1.58 mm h~(-1) over the eastern Tibetan Plateau).The 3D morphology was defined as the ratio of the average vertical scale to the average horizontal scale, where a large value corresponds to thin and tall, and a small value corresponds to plump and short. Thin-and-tall precipitation areas and plump-and-short precipitation areas had a greater median RRav, whereas the precipitation areas with a moderate 3D morphology had the lowest median RRav. The vertical structure of the precipitation-area reflectivity was sensitive to both size and 3D morphology, but was not sensitive to the horizontal shape. The relationship between RRav and the morphological characteristics was most significant over the southern slopes of the Tanggula Mountains and the Tibetan Plateau east of 100°E. The morphological characteristics of precipitation areas are therefore closely related to the intensity of precipitation and could potentially be used to forecast precipitation and verify numerical models. 展开更多
关键词 precipitation areas morphological characteristics tibetan Plateau TRMM PR
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Comparison of LR,5-CV SVM,GA SVM,and PSO SVM for landslide susceptibility assessment in Tibetan Plateau area,China 被引量:1
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作者 ZHANG Ying-bin XU Pei-yi +5 位作者 LIU Jing HE Jian-xian YANG Hao-tian ZENG Ying HE Yun-yong YANG Chang-feng 《Journal of Mountain Science》 SCIE CSCD 2023年第4期979-995,共17页
The applicability of statistics-based landslide susceptibility assessment methods is affected by the number of historical landslides.Previous studies have proposed support vector machine(SVM)as a small-sample learning... The applicability of statistics-based landslide susceptibility assessment methods is affected by the number of historical landslides.Previous studies have proposed support vector machine(SVM)as a small-sample learning method.However,those studies demonstrated that different parameters can affect model performance.We optimized the SVM and obtained models as 5-fold cross validation(5-CV)SVM,genetic algorithm(GA)SVM,and particle swarm optimization(PSO)SVM.This study compared the prediction performances of logistic regression(LR),5-CV SVM,GA SVM,and PSO SVM on landslide susceptibility mapping,to explore the spatial distribution of landslide susceptibility in the study area in Tibetan Plateau,China.A geospatial database was established based on 392 historical landslides and 392 non-landslides in the study area.We used 11 influencing factors of altitude,slope,aspect,curvature,lithology,normalized difference vegetation index(NDVI),distance to road,distance to river,distance to fault,peak ground acceleration(PGA),and rainfall to construct an influencing factor evaluation system.To evaluate the models,four susceptibility maps were compared via receiver operating characteristics(ROC)curve and the results showed that prediction rates for the models are 84%(LR),87%(5-CV SVM),85%(GA SVM),and 90%(PSO SVM).We also used precision,recall,F1-score and accuracy to assess the quality performance of these models.The results showed that the PSO SVM had greater potential for future implementation in the Tibetan Plateau area because of its superior performance in the landslide susceptibility assessment. 展开更多
关键词 tibetan Plateau area Logistic regression Support vector machine Landslide susceptibility assessment
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Community participation mode of ecotourism in Tibetan area of Shangri-La County, Yunnan Province 被引量:2
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作者 Cheng Zhu 《Ecological Economy》 2006年第3期306-318,共13页
Community participation is one of the focuses of the research on ecotourism. The research on community participative model is of great theoretical and practical significance. Based on the former experts’ studies, thi... Community participation is one of the focuses of the research on ecotourism. The research on community participative model is of great theoretical and practical significance. Based on the former experts’ studies, this paper analyzes ecotourism demonstration areas in Diqing Shangri-La of Yunnan as a case study. It mainly expounds the relationship between ecotourism and community participation and puts forward such a community participative model of ecotourism in Shangri-La. 展开更多
关键词 Community participation MODEL ECOTOURISM Shangri-La tibetan area
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Genesis of the Cenozoic Sodic Alkaline Basalt in the Xiahe–Tongren Area of the Northeastern Tibetan Plateau and its Continental Dynamic Implications 被引量:1
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作者 LAI Shaocong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第3期1047-1048,共2页
Objective The Cenozoic Indo-Asian collision caused significant crustal shortening and plateau uplift in the central Tibet. The extrusion tectonic model has been widely accepted to explain the strike-slip faults around... Objective The Cenozoic Indo-Asian collision caused significant crustal shortening and plateau uplift in the central Tibet. The extrusion tectonic model has been widely accepted to explain the strike-slip faults around the Tibetan Plateau. Previous studies indicate that the lower crust flow is the main drive force of the extrusion tectonics. Whether mantle extrusion process occurred during the Cenozoic uplift is a major problem to be addressed, which is significant for understanding the uplift mechanism and tectonic evolution of the Tibetan Plateau. 展开更多
关键词 Tongren area of the Northeastern tibetan Plateau and its Continental Dynamic Implications Genesis of the Cenozoic Sodic Alkaline Basalt in the Xiahe
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Multi-level Cooperation and Complementary Advantage Poverty Alleviation Model in Poverty-Stricken Counties of Tibetan Areas:A Case Study of Songpan County in Sichuan Province
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作者 Feng QIU Zisheng YANG +1 位作者 Kai RAO Qiude LI 《Asian Agricultural Research》 2019年第10期66-75,共10页
Songpan County is a poverty-stricken county in Tibetan areas of Sichuan Province,it belongs to a concentrated poverty-stricken area in China.Through summarizing the specific conditions of multi-level cooperation and c... Songpan County is a poverty-stricken county in Tibetan areas of Sichuan Province,it belongs to a concentrated poverty-stricken area in China.Through summarizing the specific conditions of multi-level cooperation and complementary advantage poverty alleviation model in Songpan County,this paper analyzed the effect of this model.Through the analysis on the cooperative poverty alleviation model(eastern-western cooperation,provincial targeted assistance,county-wide"four-leading and four-assistance"inner-party assistance,social force"10000 enterprises helping 10000 villages",and"visiting every household and keeping every person busy"),it summarized the implementation and actual results of each level.In addition,it summarized the problems encountered in the implementation process of multi-level cooperation and complementary advantage poverty alleviation model and came up with recommendations.With the aid of this successful multi-level cooperation and complementary advantage poverty alleviation model,Songpan County has achieved a decisive victory in the fight against poverty.At the end of April 2019,the poverty rate in the whole region fell to 0.45%,and it successfully took off the poverty hat.This paper analyzed and refined the specific practice,main achievements,successful experience,implications and reference significance of multi-level cooperation and complementary advantage poverty alleviation model,to provide necessary references for innovation of poverty alleviation model in poverty-stricken Tibetan areas,or even other similar provinces and regions. 展开更多
关键词 MULTI-LEVEL COOPERATION POVERTY alleviation ACHIEVEMENTS POVERTY-STRICKEN COUNTY in tibetan areas Songpan COUNTY
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Perfecting the Market-Oriented Ecological Compensation Mechanism of Ethnic Minority Areas: A Case Study of Gannan Tibetan Autonomous Prefecture
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作者 HE Aihong WANG Yilong 《Journal of Landscape Research》 2017年第4期45-48,52,共5页
The construction of the market-oriented ecological compensation mechanism in China is complicated system engineering. China's ecological compensation funds are mainly derived from the public finance, lacking marke... The construction of the market-oriented ecological compensation mechanism in China is complicated system engineering. China's ecological compensation funds are mainly derived from the public finance, lacking market-oriented operation. That not only increases the financial burden of the government, but also leads to the incomprehensive compensation scope. Moreover, China's ecological compensation lacks market mechanism so that it is difficult to set compensation standards and calculate offsets. This paper takes Gannan Tibetan Autonomous Prefecture as an example to analyze the market-oriented ecological compensation system of ethnic minority areas from the perspective of market economy, so as to provide a theoretical basis and a reference point for the establishment of efficient and reasonable ecological compensation mechanism and policies in ethnic minority areas and provide environmental protection for the sustainable development of economy and society of ethnic minority areas. 展开更多
关键词 Ethnic Minority areas Market-oriented ecological compensation mechanism Gannan tibetan Autonomous Prefecture
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Applicable Garden Ground Cover Plants in Arid Valleys of Ganzi Tibetan Area
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作者 XIE Xueqiang 《Journal of Landscape Research》 2020年第2期95-98,共4页
The native and introduced ground cover plants were screened by field survey,cultivation test and configuration effect evaluation in arid valleys of Ganzi Tibetan area.A total of 205 species belonging to 140 genera,67 ... The native and introduced ground cover plants were screened by field survey,cultivation test and configuration effect evaluation in arid valleys of Ganzi Tibetan area.A total of 205 species belonging to 140 genera,67 families were selected as applicable types.Among them,there were 53 species of evergreen shrubs,36 species of deciduous shrubs,17 species of woody vines,99 species of herbaceous plants;27 species of color-leafed plants,8 species of succulent plants.And 79 species were recommended as the best ground cover plants.Higher plants in Ganzi Tibetan area were increased to 5,362 species,1147 genera,244 families through screening. 展开更多
关键词 Ganzi tibetan area ARID VALLEY Higher PLANTS GARDEN PLANTS Ground cover PLANTS Colorleafed PLANTS SUCCULENT PLANTS Resource PLANTS
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Atmospheric Carbon Dioxide Reconstruction and Ocean Acidification Deduced from Carbon Isotope Variations across the Triassic–Jurassic Boundary in the Qiangtang Area, Tibetan Plateau
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作者 YI Fan YI Haisheng +1 位作者 XIA Guoqing CAI Zhanhu 《Acta Geologica Sinica(English Edition)》 CAS CSCD 2018年第5期2055-2057,共3页
Objective The end-Triassic mass extinction was one of the five most profound Phanerozoic extinction events.This event was accompanied by a series of significant environmental changes,of which the most notable is the e... Objective The end-Triassic mass extinction was one of the five most profound Phanerozoic extinction events.This event was accompanied by a series of significant environmental changes,of which the most notable is the emergence of warm climate and the world-wide disappearance of carbonate platform. 展开更多
关键词 PCO Ca Jurassic Boundary in the Qiangtang area tibetan Plateau Atmospheric Carbon Dioxide Reconstruction and Ocean Acidification Deduced from Carbon Isotope Variations across the Triassic
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Petrogenesis of high-Mg# Cenozoic volcanic rocks of southern Qiangtang area, Tibetan Plateau: geochemical and Sr-Nd isotopic evidence
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作者 FAN Lefu CHI Xiaoguo +3 位作者 LIU Jianfeng ZHANG Rui WANG Limin SUN Wei 《Global Geology》 2015年第3期174-182,共9页
The Nadingcuo volcanic rock suite is the most volmninous Cenozoic volcanic suite in the southern Qiangtang area of the northern Tibetan Plateau. These high-K calc-alkaline volcanic rocks were formed between 36 and 34 ... The Nadingcuo volcanic rock suite is the most volmninous Cenozoic volcanic suite in the southern Qiangtang area of the northern Tibetan Plateau. These high-K calc-alkaline volcanic rocks were formed between 36 and 34 Ma, characterized by high Mg# values, high concentrations of TiO2 and P205, 87Sr/S6Sr ratios of 0. 704682--0. 706 112, and aNd(t) values of - 1.2 to 1.6. There is a lack of reasonable explanations for sour- cing and origin of magmas that formed the rocks with high Mg# values and TiO2 and P2O5 enrichments, which makes the previous research results still controversial. This study reviews the geochemical characteristics of Nadingcuo volcanic rocks and the data we have newly found in our fieldwork. We give some new interpretation to the magmatic evolution of the basaltic magmas in the discussed area dominated by fractional crystallization. The geochemistry of trachyandesite and trachyte units in the studied area is indicative of formation from mantle- derived magmas that mixed with crustal materials. The high values of Mg# and TiO2 and P205 enrichment in these units are evident to show the mixing between mantle-derived magmas with -30-40 wt.% rhyolitic melt or assimilation of a similar amount of felsic rocks. The geochemistry of basaltic rocks in the area also suggests that the Nadingcuo basalts may have been derived from an ocean island basalt (OIB) -type source that contained and was mixed with ancient mantle wedge derived material, indicating that a 36-34 Ma asthenospheric upwelling e- vent in the Qiangtang area may relate to the northward subduction of Indian lithospheric mantle and the south- ward subduction of Asian lithospherie mantle. This upwelling of asthenospherie material was centered in the southern Qiangtang area between 36 and 34 Ma, while the northward movement of the Indian Craton caused this upwelling mantle flow to continuously migrate northward, resulting in the current centering of this upwelling in the Hoh Xil-Kunlun region. 展开更多
关键词 tibetan Plateau southern Qiangtang area high-Mg# volcanic rocks Sr-Nd isotopic composition
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Occurrence of microplastics in natural and farmland soil in the Qilian Mountains of the Northern Tibetan Plateau
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作者 KANG Qiangqiang ZHANG Yulan +5 位作者 KANG Shichang ZHANG Shengyin LUO Xi LI Longrui WANG Zhaoqing ZHANG Shuncun 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2159-2172,共14页
Microplastics(MPs)become ubiquitous in soil and are an environmental and public health concern worldwide.However,the status of MPs in natural and farmland soils in remote areas remains poorly understood.In this study,... Microplastics(MPs)become ubiquitous in soil and are an environmental and public health concern worldwide.However,the status of MPs in natural and farmland soils in remote areas remains poorly understood.In this study,we investigated the characteristics of MPs in natural and farmland soils along two transects in the Qilian Mountains of the northern Tibetan Plateau.The average abundance of MPs in natural and farmland soils was 29,778 and 56,123 items kg^(-1),respectively,with a detection size range of 10-1000μm.MPs in the size range of 10-100μm accounted for 84.1%of particles detected.Among the 21 polymers detected,polyethylene dominated in both farmland and natural soils.The shape of MPs was dominated by fragments(95.8%),followed by fibers(3.8%)and beads(0.4%).The abundance of MPs was positively correlated with increasing altitude in natural soils.There was no significant correlation between the abundance of MPs and soil physicochemical properties due to the narrow range of values of soil physicochemical properties.With the growing concern regarding MPs pollution,research on the status of MPs in high altitude and remote areas is critical to understanding their global cycle. 展开更多
关键词 Microplastics pollution SOIL Remote areas tibetan Plateau
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Study on Rural Poverty in Ecologically Fragile Areas——A Case Study of the Tibetan Areas in Sichuan Province
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作者 LAN Hong-xing Sichuan Agricultural University, Ya’an 625014, China 《Asian Agricultural Research》 2012年第1期27-31,61,共6页
This article offers an overview of natural environment, economic development, and social development in the Tibetan areas in Sichuan Province. The major manifestations of the status quo of poverty in the Tibetan areas... This article offers an overview of natural environment, economic development, and social development in the Tibetan areas in Sichuan Province. The major manifestations of the status quo of poverty in the Tibetan areas are as follows: there is a wide range of poverty and a large poor population; the poverty degree is high and it is difficult to alleviate poverty; the natural disasters are frequent and the phenomenon of poverty arising from disasters is serious. We analyze the factors responsible for poverty of farmers and herdsmen in Sichuan Province as follows: first, the natural conditions are inclement and the ecological environment is fragile; second, the social attitudes are stale and the religious influence is deep; third, the development of education lags behind, the human capital inputs are short and the self-development capacity is weak; fourth, the state poverty alleviation and development policy is weakly directed at region; fifth, the Tibetan areas are facing the dilemma of choosing resources endowments or ecological protection. Following proposals are put forward to resolve the poverty issue in the Tibetan areas of Sichuan Province: strengthen infrastructure construction, and underpin self-development capacity of the Tibetan areas in Sichuan Province; reinforce organic connection of social security and poverty alleviation and development, and promote self-development capacity of impoverished farmers and herdsmen in the Tibetan areas; strengthen policy support, and improve self-development policy and mechanism of the Tibetan areas in Sichuan Province; drive the popularization of technology and culture in the Tibetan areas, and update the development concept of farmers and herdsmen in the Tibetan areas; accelerate the development of competitive industries in Tibetan areas, and promote economic development capacity of the Tibetan areas. 展开更多
关键词 Ecologically fragile areas POVERTY ISSUE Self-deve
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Cableways in the Tibetan Area
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作者 LI YUCHUAN 《China's Tibet》 1995年第6期24-25,共2页
CablewaysintheTibetanAreaLIYUCHUANTheinitialmethodinvolvedenclosingthestripsinwoodentubesoutfittedwithseats.... CablewaysintheTibetanAreaLIYUCHUANTheinitialmethodinvolvedenclosingthestripsinwoodentubesoutfittedwithseats.Peopleweretranspo... 展开更多
关键词 Cableways in the tibetan area
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A Trip to Tibetan Areas in Sichuan and Qinghai
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作者 WANG LUO 《China's Tibet》 1995年第6期36-37,共2页
ATriptoTibetanAreasinSichuanandQinghaiWANGLUOInsummerlastyear,myfriendsandItravelledtotheTibetanareasinSichu... ATriptoTibetanAreasinSichuanandQinghaiWANGLUOInsummerlastyear,myfriendsandItravelledtotheTibetanareasinSichuanandQinghaiprovi... 展开更多
关键词 A Trip to tibetan areas in Sichuan and Qinghai
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Contrasting vegetation changes in dry and humid regions ofthe Tibetan Plateau over recent decades 被引量:3
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作者 RuiQing Li YanHong Gao +2 位作者 DeLiang Chen YongXin Zhang SuoSuo Li 《Research in Cold and Arid Regions》 CSCD 2018年第6期482-492,共11页
An overall greening over the Tibetan Plateau(TP) in recent decades has been established through analyses of remotely sensed Normalized Difference Vegetation Index(NDVI), though the regional pattern of the changes and ... An overall greening over the Tibetan Plateau(TP) in recent decades has been established through analyses of remotely sensed Normalized Difference Vegetation Index(NDVI), though the regional pattern of the changes and associated drivers remain to be explored. This study used a satellite Leaf Area Index(LAI) dataset(the GLASS LAI dataset) and examined vegetation changes in humid and arid regions of the TP during 1982–2012. Based on distributions of the major vegetation types, the TP was divided roughly into a humid southeastern region dominated by meadow and a dry northwestern region covered mainly by steppe. It was found that the dividing line between the two regions corresponded well with the lines of mean annual precipitation of 400 mm and the mean LAI of 0.3. LAI=0.3 was subsequently used as a threshold for investigating vegetation type changes at the interanual and decadal time scales: if LAI increased from less than 0.3 to greater than0.3 from one time period to the next, it was regarded as a change from steppe to meadow, and vice versa. The analysis shows that changes in vegetation types occurred primarily around the dividing line of the two regions, with clear growth(reduction) of the area covered by meadow(steppe), in consistency with the findings from using another independent satellite product. Surface air temperature and precipitation(diurnal temperature range) appeared to contribute positively(negatively) to this change though climate variables displayed varying correlation with LAI for different time periods and different regions. 展开更多
关键词 tibetan Plateau vegetation change leaf area index climate change
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Ice-wedge Pseudomorphs Showing Climatic Change Since the Late Pleistocene in the Source Area of the Yellow River, Northeast Tibet 被引量:3
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作者 CHENG Jie ZHANG Xujiao +4 位作者 TIAN Mingzhong YU Wenyang YU Jiangkuan TANG Dexiang YUE Jianwei 《Journal of Mountain Science》 SCIE CSCD 2005年第3期193-201,共9页
The source area of the Yellow River is located in the northeastern Tibetan Plateau, and is a high-elevation region with the annual mean temperature of -3.9℃. The ice-wedge pseudomorphs discovered in this region are r... The source area of the Yellow River is located in the northeastern Tibetan Plateau, and is a high-elevation region with the annual mean temperature of -3.9℃. The ice-wedge pseudomorphs discovered in this region are recognized as two types. One was found in sandy gravel beds of the second terrace of the Yellow River. This ice-wedge pseudomorph is characterized by higher ratio of breadth/depth, and are 1-1.4 m wide and about 1 m deep. The bottom border of the ice-wedge pseudomorph is round arc in section. Another discovered in the pedestal of the second terrace has lower ratio of width/depth, and is o.3-1.0 m wide and 1-2 m deep. Its bottom border is sharp. Based on the TL dating, the former was formed at the middleHolocene (5.69±0.43 ka BP and 5.43±0.41 ka BP), that is, the Megathermal, and the latter was formed at the late Last Glacial Maximum (13.49±1.43 ka BP). Additionally, the thawing-freezing folders discovered in the late Late Pleistocene proluvium are 39.83±3.84 ka BP in age. The study on the ice-wedge pseudomorphs showed that the air temperature was lowered by up to 6-7℃ in the source area of the Yellow River when the ice-wedge pseudomorphs and thawing-freezing folds developed. 展开更多
关键词 Ice-wedge pseudomorph PALEOCLIMATE Last Glacial Age MEGATHERMAL the source area of the Yellow River tibetan Plateau
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NO_x Release from Snow and Ice Covered Surface in Polar Regions and the Tibetan Plateau
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作者 Feng Wang Weili Lin +1 位作者 Junxia Wang Tong Zhu 《Advances in Climate Change Research》 SCIE 2011年第3期141-148,共8页
The exchanges of NOx between snow and air have significant impact on the atmospheric components and photochemical processes in the overlying boundary layer. Such exchanges increase the oxidizing capacity of the atmosp... The exchanges of NOx between snow and air have significant impact on the atmospheric components and photochemical processes in the overlying boundary layer. Such exchanges increase the oxidizing capacity of the atmosphere and may have a crucial impact on the air signals that are retrieved from ice cores. In the recent years, sunlit snow and ice have been demonstrated to be important NOx sources in the polar atmospheric boundary layer. This paper makes a thorough review on the release of NOx from snow and ice, including field observations and experimental evidences, release mechanisms and influential parameters that affect such a release process, polar NOx concentrations and fluxes, and environmental impacts of the chemical processes of NOx in the polar atmospheric boundary layer. In the Tibetan Plateau, the released NOx observed recently in the sunlit snow/ice-cover is 1-order magnitude more than that in polar regions, but further scientific research is still needed to reveal its impact on the atmospheric oxidizing capacity. 展开更多
关键词 NOx exchange between snow and air polar area atmospheric oxidizing capacity tibetan Plateau
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Estimation of Economic and Ecological Value of Raising Sheep in Pastoral Area
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作者 Zenghai LUO Shengzhen HOU +3 位作者 Zhiyou WANG Yuchun XIN Huakun ZHOU Guiying YUAN 《Asian Agricultural Research》 2020年第6期4-8,12,共6页
Tibetan sheep is a unique breed of livestock in Alpine pastoral areas,which is one of the main economic pillars of animal husbandry in pastoral areas,in order to analyze and compare the estimated the economic and ecol... Tibetan sheep is a unique breed of livestock in Alpine pastoral areas,which is one of the main economic pillars of animal husbandry in pastoral areas,in order to analyze and compare the estimated the economic and ecological benefits of Tibetan sheep under different feeding modes,this paper used a simplified model from multiple angles of animal production,economics and Ecology,The results show that:(i)Under the traditional grazing condition,the annual income of raising one ewe is only 23.4 yuan;(ii)Under the high-efficiency breeding mode,the average income of ewes bred by high-efficiency technology was 168 yuan/(head·year),which was 7 times higher than that of ewes under traditional grazing;each lamb could produce an indirect economic benefit of 500 yuan;(iii)The ecosystem service value affected by each Tibetan sheep through grassland was above 150000 yuan. 展开更多
关键词 tibetan sheep Alpine pastoral area Traditional grazing Ecological value
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