Insights into the long-term stability of landslide dams on the eastern margin of the Tibetan Plateau, China——A case study of the Diexi area

Landslide dams,especially long-term stable landslide dams,have been recognized as important contributors to regional geomorphological evolution.Here,the Diexi area,a long-term stable dam-prone area located in upstream of the Minjiang River on the eastern Tibetan Plateau,was adopted to reveal reasons that landslide dams are concentrated in this area and maintain long-term stability via detailed field investigations,landslide dam sampling,unmanned aerial vehicle(UAV)images,and digital surface models(DSM).The results show the controlling factors that the slopes are prone to sliding and rock mass structure deterioration including lithological combination mode,slope structure,topographic conditions,a series of NNE-trending radial fissures and hydrological conditions.Fault activities,which have caused many earthquakes,are the main inducing factor.Landslide dams are prone to occurrence in the Diexi area owing to the combined effect of the narrow channels,the large landslide dam volume and the rock fragments.The river flow,and the landslide dam volume,material,structure,and parameters control the stability of landslide dams.The landslide dam consists of various sizes of boulders and all landslide dams exhibit an obvious inverse grading sequence,and this size combination could consume most of the flow energy,and consequently protect the dam from incision.Additionally,a total of seven knickpoints were formed by landslide dams,and the longitudinal gradient upstream of every landslide dam was found to decrease by the action of knickpoint.In the eastern margin of the Tibetan Plateau,there are numerous landslide dams existed for hundreds or thousands of years.Studies on the long-term stable landslide dams in the Diexi area could provide experience for studying similar kinds of landslide dams in this region.

东北方言“蹀躞”的词义分析

"蹀躞"在东北方言中多达五个意思,分别是走路踉跄;频繁往来走动;搬运;颤悠的样子;显摆等。分析这些词义的来源和发展,探索词义演变的规律,可以推动东北方言的历时研究,从而为整个汉语史的发展演变研究提供方言支撑和佐证。

辽代玉蹀躞带的特征分析及其文化探源

辽代玉蹀躞带是辽代重要的礼仪器,是契丹民族与其他民族进行文化交流和互动的重要见证物。本文通过对辽代玉蹀躞带进行系统地考察和分析,发现它们在形式上可分为单带扣.单铊尾型和双带扣.双铊尾型两类。前者以蹀躞銙上具有"山"字形古眼、蹀躞上坠饰倒悬葫芦形带饰或曲柄形饰以及带銙可能存在偏角团形銙或倒"凸"字形銙为特征,在文化渊源上主要受到突厥文化、回鹘文化的影响。后者以具有前后两组玉带为特征,其主要受到中原汉族带饰文化的影响。本文中关于辽代玉蹀躞带中存在悬坠曲柄形饰、饰倒"凸"字形銙以及还具有双带扣.双铊尾型式的特征分析在过去的研究中少为述及,可作为新的依据,帮助我们更全面地把握辽代玉蹀躞带的特征和更深刻地理解辽代社会契丹文化的特色及其多元文化的内涵。

论“蹀躞”的词义变异

'蹀躞'有'行走'义,由'蹀'和'躞'词汇化而来。'蹀'由踩踏产生行走义。'躞'与'屧'音义相同,都有踩踏义。'蹀躞'表示腰带,不是指佩带上的饰物。'蹀躞'与俄语词表示'带子'的词语读音相近。'蹀躞、哆嗦、嘚瑟'的颤抖义是从'抖擞'演变来的',蹀躞'不是'哆嗦'词义的源头。

敦煌莫高窟壁画吐蕃赞普服饰考——翻领与云肩、靴及蹀躞带

以敦煌莫高窟第158、159、231窟壁画为依据,对吐蕃赞普服饰进行了概述和考证,对赞普服装的穿着方式做了推断,并就其服饰中的翻领、云肩、革带、蹀躞七事及乌靴做了细致分析和探讨。

珍贵的史料--陶然士的《1933年8月叠溪地震及震后情况》

英国传教士陶然士(T.Torrance)曾长期在中国四川居住,亲身经历过1933年四川叠溪地震。1934年7月,他又到地震现场进行考察,事后写成The Tieh-chi earthquake of August 1933 and afterwards(1933年8月叠溪地震及震后情况)一文,同年11月发表在The West China Missionary News(华西教会新闻)上。本文介绍了陶然士的生平和他在叠溪地震时的经历,披露了《1933年8月叠溪地震及震后情况》一文的主要内容,并进行了评述。陶然士在他的文章中对叠溪地震灾害及其次生水灾的记述基本客观真实,不少细节可以与地质学家常隆庆的《四川叠溪地震调查记》以及后人的研究成果相互印证,具有一定的科学价值,是又一份珍贵的地震史料。并对进一步发掘有关地震史料等有关问题提出了建议。

辽代官服“蹀躞带”带銙之形制渊源考

"蹀躞带"是中国古代北方草原游牧民族服饰的重要组成部分,伴随少数民族政权的建立,在官服体系中具有强烈的等级象征意味。目前学界对辽代官服"蹀躞带"的带銙形制及其渊源尚少探究,因此,本文拟从质料、形状、数量、纹饰等角度加以考辨。

Reproduction of the Sedimentary Disturbance Phenomenon of the Diexi Ancient Landslide-Dammed Lake under Earthquake

Valuable geological and environmental information can be obtained from the 200 m thick lacustrine sediments in the Diexi lake(an ancient landslide-dammed lake) of the Minjiang River. The shaking table test method was employed to study the disturbance phenomena which occurred in the Diexi lake sediments. The results show that the disturbance phenomena were caused by liquefaction-induced flows in the unconsolidated lacustrine sediments, due to triggering by earthquakes. The deformations only occurred in unconsolidated sediment layers and not in consolidated layers. This means that a consolidated layer cannot be liquefied and disturbed again by an earthquake for a second time. The disturbance on one layer corresponds to only one earthquake. The temporal occurrence of earthquakes could be determined by disturbance layers generated at different ages. In total, 10 disturbed layers were found in the lacustrine sediments of the Diexi lake. The experiments showed that there were more than 10 earthquakes between 30 ka B.P. and 15 ka B.P. in the Diexi lake area based on the dating of the disturbed sediment layers.

South Segment of Minjiang Fault and Diexi Earthquake in 1933

Diexi earthquake(M7.5)in 1933 is a great event that occurred at the east border of Qinghai- Xizang Plateau in the 20th century.There are obviously different opinions about the shape ofisoseismal lines and the genetic fault of this earthquke.Based on the study of the newlyfound north-south trending active fault and ground fissures of Diexi earthquake,this papertends to hold that,as the southward extension of Miujiang fault,this north-south trendingactive fault might be the genetic fault of this event.

内蒙古地区出土辽代蹀躞带考

自20世纪中叶以后,国内外学者从多角度对唐、辽蹀躞带做了不同程度的探讨和研究,成果颇丰,但是仍有许多问题需要探讨。本文运用内蒙古地区出土的大量考古材料,经过系统分析和比较,对其做了分类与分期。内蒙古地区出土的蹀躞带,从形态上可分为三类:双带扣双铊尾带、双带扣单铊尾带及单带扣单铊尾带。又依照蹀躞带的不同特点分为三期进行探讨,并对辽蹀躞带形成的诸文化因素进行了研究。

Late Pleistocene environmental information on the Diexi paleo-dammed lake of the upper Minjiang River in the eastern margin of the Tibetan Plateau, China

In 1999, Diexi paleo-dammed lake(2349 m a.s.l.) was discovered around Diexi town along the Minjiang River in Sichuan province. Diexi is located where the eastern edge of the Tibetan Plateau and the Sichuan Basin meet. The dammed lake was formed during the Last Glacial Maximum of the Late Pleistocene(~30,000 years ago) and began to empty about 15,000 years ago. The lacustrine sediments(up to 240 m thick) preserve abundant paleoenvironment information. In this paper, a mass of oxygen isotopes and 14 C dating from drilled cores are analyzed and discussed. The δ18 O curve on the paleo climate from this section is comparable with the coeval paleo climatic curves of ice cores and karsts in China and others. Furthermore, the physical model testing has confirmed that the disturbed zones in the core are caused by strong earthquakes occurred at least 10 times, which implies strong crustal deformation, as an important driving force, affecting climate change. This study provides a new window to observe East Asian monsoon formation, paleoenvironmental evolution and the global climate change.

Possible relatedness between the outburst of the Diexi ancient dammed lake and ancient Chengdu’s cultural change

The Diexi ancient dammed lake is in the upper reaches of the Minjiang River.Six terraces with lacustrine sediments occur at the base.These terraces are the products of the graded outburst of the Diexi ancient dammed lake.The outburst of the ancient dammed lake would certainly have had an impact on the Chengdu Plain in the lower reaches of the Minjiang River.In this paper,on-site sampling and laboratory analysis were used to analyze the sediments of the Diexi ancient dammed lake and the Jinsha site in Chengdu Plain,and the environmental indicators of each sediment layer were tested.Through a comparative analysis of the environmental indicators in the sediments at the two locations,the following results were obtained:the palaeoclimatic and palaeoenvironmental characteristics at the two locations generally show consistent changes.The most important finding is that the types and content of the major pollen taxa at the two locations are similar.The Pinus content strongly proves that the soil layers at the Jinsha site was sourced from the upper reaches of the Minjiang River.Considering that the demise of the ancient culture at the Jinsha site occurred close in time to the outburst of the ancient dammed lake,this similarity suggests that the cultural change at the Jinsha site may have been related to the outburst of the Diexi ancient dammed lake.

Re-discussion on the Jiaochang Arcuate Structure, Sichuan Province, and the Seismogenic Structure for Diexi Earthquake in 1933

The Jiaochang arcuate structure is one of the numerous arcuate structural belts in Sichuan. The present paper gives a further argument about the characteristics of that arcuate structure and the new activity of the Songpinggou fault and affirms that the Songpinggou fault is an active fault in the Holocene epoch. The Diexi M 7.5 earthquake took place in 1933 on the west wing of that arcuate structure, near the apex of the arc. Many authors have given quite different opinions about the genetic structure of that earthquake. The authors have made on the spot investigations time and again over recent years. Besides this, the authors have also further studied the shape of intensity contour lines, the distribution characteristics of ground surface seismic hazards, the left lateral dislocation of buildings along the Songpinggou fault, the NW trending ground fissures that developed on the ground surface after earthquake, and so on. On this basis, it is still considered that the seismogenic fault of the 1933 Diexi M 7.5 earthquake was the Songpinggou fault on the west wing of the Jiaochang arcuate structure.

蹀躞东关街

扬州有五百多条纵横交错的街巷，最古老最繁华的当属东关街了。东关街位于古城扬州东北角，因为街道由西向东直抵东关城门，或者说直抵东关古渡，故名东关街。这里有鱼骨状街巷体系，有夹巷、支巷、串巷，或长或短、或宽或窄、或直或弯，回环反复，首尾相连，内外相通……

说文——玉带(蹀躞带)

蹀躞带是一种缀以垂饰的革带,带上钉有若干枚带銙,銙上备有小环,环上套挂若干小带,以便悬挂各种日常用具。蹀躞带源于北方草原民族的胡服,便于乘骑,后传入中原,是用来佩带刀剑、算囊、刀砾等日常用品,流行于北周至唐初。玉带最早出现于魏晋南北朝时期,一直延续到明代,由蹀躞带发展而来。玉带,是指用玉装饰的皮革制的腰带。而革带上起装饰作用的玉饰片,称为"玉带銙"。一条完整的革带应由鞓,銙、铊尾和带扣四部分组成。镶在带两端一侧为半圆形带板叫"铊尾",带扣和铊尾就类似于我们现在的皮带扣和皮带尾部的装饰,鞓是指皮质的腰带,带銙也称为带板,镶缀在鞓上,形状有方形、半圆形等等,有的带銙上还有孔或者附环(如蹀躞带),用来悬挂物品。

四川叠溪松坪沟断层的厘定

1933年8月25日四川叠溪发生M_(S)7.5地震,一种代表性的观点认为松坪沟断层为此次地震的发震构造。而对于松坪沟断层的存在、发育分布以及其活动性,学者们至今仍存在一定的分歧。本文基于前人研究成果,对松坪沟中下游(松坪沟沟口至墨石寨)进行了详细的野外地质调查,并结合地球物理探测,证实了松坪沟断层的存在;松坪沟断层整体走向NW,沿松坪沟呈三段斜列式展布(NW段、中间段和SE段),其NW段倾向NE,中间段和SE段倾向SW,倾角约55°-80°;松坪沟断层以左旋走滑运动为主、兼逆冲性质,在距今两万年以来有过活动。最后通过对松坪沟流域地貌参数分析表明,该区地貌发育上处于幼年期晚期和壮年期,构造活动强烈,且松坪沟断层中间段和SE段的活动性较NW段强烈。

上海徐家汇观象台记录的1933年四川叠溪地震参数计算

地震学者对1933年叠溪大地震进行了大量研究,由于资料匮乏,学术界至今对该地震的震源位置、震级、发震时间3要素有不同看法。本文利用上海徐家汇观象台1933年四川叠溪大地震三分向记录,通过对叠溪地震事件图纸的重新分析校核,利用IASP91全球走时模型对发震时间、震中距和震级3要素重新行计算和反演,得出的定位结果为:发震时刻为1933年8月25日7时50分15秒、震中距为16.25°、震级为M_(S)7.49。该结果和其他研究学者在发震时刻和震中距上偏差较大,发震时刻相差17 s,震中距相差1°左右,两者偏差较大,究其原因是采用的方法不同,前人是基于宏观资料、现场调查以及后续小震反演得到的结果。

岷江断裂南段与1933年叠溪地震研究

1933年叠溪75级地震是发生在青藏高原东南缘的重大事件。对这次地震的等烈度线形态及与之相关的发震构造的认识有着明显的分歧。本文基于野外新发现的南北向活动断裂以及叠溪地震地面破裂的研究。

岷江叠溪古堰塞湖的发现

1933年8月25日,四川岷江上游叠溪发生了一次7.5级地震。在叠溪地震引发的较场大滑坡上覆盖有较古老的厚土层,国内学者对其成因有不同解释。作者在开展叠溪地震滑坡调研中,发现并确认这是一套古堰塞湖相沉积物,当时的堰塞坝处在原叠溪古镇至下游马老顶乡一带长达数千米的河段,因此定名为叠溪古堰塞湖。古堰塞湖相沉积物厚度最大可达200余米,为一套层理清晰的粉土-黏土层。由叠溪向上游约30km河段,沿江断续可见这套沉积物,且有明显的相变。14C测年,湖相沉积物底部形成时代距今22ka,顶部距今约10ka,据此判断叠溪古堰塞湖维持了12ka。此外作者在较场一带还发现了以湖相沉积物为"基座"的五级"阶地",这些"阶地"上保存完好的二元结构河流相沉积物。该文较系统地介绍了叠溪古堰塞湖的基本特征,初步论述了其中包含的地质环境信息。

四川较场弧形构造与1933年叠溪地震发震构造的再讨论

较场弧形构造是四川众多弧形构造带之一。本文对该弧形构造的特征及其西翼发育的松平沟断裂的新活动性作了进一步论证 ,确认松平沟断裂属全新世活动断裂。该弧形构造西翼靠弧顶部位 1933年曾发生过叠溪 7 5级地震。前人对该次地震的发震构造众说纷纭。作者通过近年来在现场的多次考察 ,并对该次地震的等烈度线形态、地表震害展布特征、建筑物沿松平沟断裂的左旋位错、震后地表发育的北西向地震地裂缝等现象的进一步研究认为 ,1933年叠溪 7 5级地震的发震构造仍为较场弧形构造西翼的松平沟断裂。