Comparison of LR,5-CV SVM,GA SVM,and PSO SVM for landslide susceptibility assessment in Tibetan Plateau area,China

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.

Occurrence of microplastics in natural and farmland soil in the Qilian Mountains of the Northern Tibetan Plateau

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.

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

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.

The Current Status of Trilingual Education in Tibetan Areas of China

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.

Land Remediation Projects in Poverty-stricken Counties in Tibetan Areas Promoting Poverty Alleviation——A Case Study of Songpan County,Sichuan Province

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.

Morphological Characteristics of Precipitation Areas over the Tibetan Plateau Measured by TRMM PR

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.

Community participation mode of ecotourism in Tibetan area of Shangri-La County, Yunnan Province

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.

Genesis of the Cenozoic Sodic Alkaline Basalt in the Xiahe–Tongren Area of the Northeastern Tibetan Plateau and its Continental Dynamic Implications

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.

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

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.

Perfecting the Market-Oriented Ecological Compensation Mechanism of Ethnic Minority Areas: A Case Study of Gannan Tibetan Autonomous Prefecture

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.

Applicable Garden Ground Cover Plants in Arid Valleys of Ganzi Tibetan Area

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.

Petrogenesis of high-Mg# Cenozoic volcanic rocks of southern Qiangtang area, Tibetan Plateau： geochemical and Sr-Nd isotopic evidence

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.

Atmospheric Carbon Dioxide Reconstruction and Ocean Acidification Deduced from Carbon Isotope Variations across the Triassic–Jurassic Boundary in the Qiangtang Area, Tibetan Plateau

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.

Study on Rural Poverty in Ecologically Fragile Areas——A Case Study of the Tibetan Areas in Sichuan Province

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.

Cableways in the Tibetan Area

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A Trip to Tibetan Areas in Sichuan and Qinghai

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甘肃涉藏地区锅庄舞风格特征研究

锅庄舞是集中体现藏民族美学思想的团栾舞蹈,由十三种舞步和九大类手势动作组合而成.颤、开、顺、左、绕、舞袖是锅庄舞的六大动作特征;走、跳是主要运动形式;圆或同心圆、弧线、直线是主要队形;舞曲多用地域风情特征明显的藏族民歌歌舞音乐,分为舒缓平和的慢板乐段和热烈奔放的快板乐段;舞蹈分为序舞、慢舞、快舞、结束四个舞段;服饰明艳华贵,主要是“藏式长袍+衬衣”;男子动作大而奔放、女子动作小而秀美.碌曲锅庄舞博采众长、久负盛名;玛曲草原锅庄舞粗犷豪放;夏河寺院锅庄舞庄严肃穆;迭部、舟曲林区锅庄舞小巧活泼;陇南、天祝山地锅庄舞稳重优美.

考虑水力连通的羌塘内流区洼地单元提取与分类

羌塘内流区是青藏高原面积最大的内流区,气候变化正在加剧其湖泊水系结构与水量的演变,开展内流区流域调查并科学估算其水资源的变化具有重要意义。本文提出一种新型内流区流域划分方法,该方法通过引入高程-面积联合阈值,以解决由气候变化与数字高程模型分辨率等因素引起的洼地单元提取难题。基于已监测的羌塘内流区流域重组与湖泊水位的变动幅度,确定了高程-面积联合阈值分别为10 m和50 km^(2),并对洼地单元进行划分,共识别出163个具有合理集水面积、永久性分水岭的封闭内流区洼地单元。引入多个相关数据集及已有算法评估本方法,结果表明:该方法适用于大尺度内流区洼地单元提取,提取精度优于现有算法及数据产品;依据洼地单元间水力连通特征,将全区163个洼地单元划分为5种主要类型,其中以“上下游互通型”(Ⅱ型)、“高山型”(Ⅳ型)洼地单元为主,“凹陷型”(Ⅴ型)洼地单元则多与其他类型复合存在,受气候条件的影响更加显著。

汉藏文化交融背景下的安多地区藏族建筑檐下装饰构件做法研究

安多地区是我国三大藏区之一,处于青藏高原向黄土高原、河西走廊、四川盆地过渡的关键地带。在汉、藏建筑文化交流与碰撞的背景下,安多地区藏族建筑基于自身地域特点发展出了“摞活”“挑头檩”“挂牌”“花板代栱”等类型多样、兼具汉藏融合特点的檐下装饰构件做法,极大丰富了藏族建筑异彩纷呈的整体面貌。以往安多地区受到了地理尺度巨大、科研力量欠缺等研究限制,而如今成为“一带一路”沿线的热点区域后,其地域性营造特征又面临着特色丧失的显著趋同化威胁,亟需对安多地区藏族建筑具有代表性和多样化的檐下装饰构件做法开展深入研究。

隋唐·安得广厦千万间--漫步地震五千年(9)

隋唐时期的史载地震主要在关中地区,显现了秦岭南侧存在一条北西向的石泉—房县活动断裂带。地震活动和房屋抗震一直是社会关注的大事,以蓟县独乐寺为典型代表,重点介绍了唐代木结构建筑的抗震技术:地基坚固和均匀、木结构的隔震机制、筒体结构的强抗震性能、斗拱构件的阻尼系统,都对后世的技术发展产生了深刻影响。在现代建筑方面,介绍了地震区划的基本原则,分析了农村藏式民居的弱点和改进措施,讨论了城市建筑的3种抗震结构及今后的发展方向。