近30年来乌鲁木齐河流域冰川波动特征与流域高山带升温幅度的估算

乌鲁木齐河流域典型冰川与全流域其他冰川波动的监测结果表明,５０年代末与６０年代初以来,各冰川均处于全面退缩状态,且冰川长度退缩量、面积和冰储量减小量与冰川的规模有密切的关系,大冰川退缩量大,但退缩量所占百分比较小,小冰川则相反,而且三者与冰川的长度等级有较好的统计关系。在区域上有更多的冰川波动资料时,可以通过优化这种统计关系用于推断无观测资料冰川在过去数十年中的波动情况,为评估区域冰川资源变化提供快捷的方法。计算说明,流域冰川全面退缩量值相当于乌鲁木齐河流域高山带在过去３０年中气温升高了０．３５±０．２７℃。     

"冰臼"与"壶穴"之争

对目前见诸报端的“冰臼”之说进行了讨论, 认为目前广东范围内所见之“冰臼”实际上是现代流水地貌之“壶穴”, 并指出, 以“冰臼”作轰动效应来吸引游客, 发展旅游业是不够严谨的。     

中国冰川编目软件设计

以数字式形式发布冰川数据,并建立信息系统对它们进行管理和分析成为趋势,中国冰川编目数据库及其管理软件的基本目标是;建立完整,规范的冰川编目数据库,促进对冰川数据的共享,研制对冰川数据进行查询,管理和分析的软件,着重讨论了中国冰川编目数据库软件的设计方法,并对冰川空间数据库和冰川数据库的网络发布作出构想。     

A Gravel Outwash/Deformation till Continuum, Skalafellsjokull, Iceland

A stratigraphic sequence exposed by river erosion in the foreland of Skalafellsjokull, southern Iceland, displays five lithofacies documenting glaciofluvial deposition followed by glaciotectonic disturbance and subglacial deformation. Lithofacies 1a and 1b are glaciotectonically thrust glaciofluvial outwash and subglacial deformation till respectively from an early advance of Skalafellsjokull. Lithofacies 2, massive gravels and clast–supported diamictons, documents the deposition of glaciofluvial outwash in the proto–River Skala prior to overriding by Skalafellsjokull during the Little Ice Age. During overriding, lithofacies 2 was glaciotectonically disturbed and now possesses the clast fabric and structural characteristics of G _B (non–penetratively deformed) and G _A (penetratively deformed) type glaciotectonites. A shear zone separates lithofacies 2 from overlying lithofacies 3, the latter possessing the clast fabric signature of a D _A (dilatant) type deformation till although it was originally deposited as a discontinuous diamicton within a glaciofluvial sequence, probably as a hyperconcentrated flow, and appears to have been at least partially derived from underlying materials by glaciotectonic cannibalization. Lithofacies 4 is a glaciofluvial deposit comprising two coarseningupward sequences of gravel and diamicton. These facies have been overprinted with G _B glaciotectonite and D _A?B (dilatant to non–dilatant) deformation till structures and clast fabrics recording a vertical progression towards more pervasively deformed material. The sequence is capped by lithofacies 5, a two–tiered deformation till possessing the characteristics of D _A and D _B horizon subglacial tills previously reported from Icelandic glacier snouts. The whole sequence comprising lithofacies 2–5 represents a gravel outwash/deformation till continuum displaying variable strain signaturesproduced in response to stress induced by the overriding of Skalafellsjokull during the Little Ice Age. These signatures are dictated by the sediment rheology and a vertical strain profile for the sediment pile during glacier overriding is reconstructed.     

希夏邦马峰冰川粒雪中环境季节变化记录研究

在希夏邦马峰达索普冰川海技７０００ｍ冰雪平台钻取１４ｍ粒雪芯一支。通过对粒雪芯中δ＾１８Ｏ和主要离子浓度的季节变化分析,认识希夏邦马峰地区大气环境的季节变化特征。相关分析和经验正交函数（ＥＯＦ）分析结果表明,达索普粒雪芯内的δ＾１８Ｏ与Ｃａ＾２＋、Ｍｇ＾２＋、ＳＯ４＾２－、ＮＯ３＾－和ＮＨ４＾＋浓度之间正相关显著,而与Ｎａ＾＋、Ｃｌ＾－和Ｋ＾＋浓度之间的关系不明显。ＥＯＦ１代表了以尘埃来源为主的离     

Monitoring glacier and supra-glacier lakes from space in Mt. Qomolangma region of the Himalayas on the Tibetan Plateau in China

Because of the large number and remoteness, satellite data, including microwave data and optical imagery, have commonly been used in alpine glaciers surveys. Using remote sensing and Geographical Information System （GIS） techniques, the paper presents the results of a multitemporal satellite glacier extent mapping and glacier changes by glacier sizes in the Mt. Qomolangma region at the northern slopes of the middle Himalayas over the Tibetan Plateau. Glaciers in this region have both retreated and advanced in the past 35 years, with retreat dominating. The glacier retreat area was 3.23 km2 （or o.75 km^2 yr^-1 during 1974 and 1976, 8.68 km^2 （or 0.36 km^2 yr^-1 during 1976 and 1992, 1.44 km^2 （or 0.12 km^2 yr^-1） during 1992-2ooo. 1.14 km^2 （or 0.22 km^2 yr^-1 during 2000-2003, and 0.52 km^2 （or 0.07 km^2 yr^-1 during 2003-2008, respectively. While supra-glacier lakes on the debris-terminus of the Rongbuk Glacier were enlarged dramatically at the same time, from 0.05 km^2 in 1974 increased to 0.71 km^2 in 2008, which was more than 13 times larger in the last 35 years. In addition, glacier changes also showed spatial differences, for example, glacier retreat rate was the fastest at glacier termini between 5400 and 5700 m a.s.l than at other elevations. The result also shows that glaciers in the middle Himalayas retreat almost at a same pace with those in the western Himalayas.     

Distribution of debris flows in Glacier National Park,Montana, U.S.A.

The spectacular scenery of Glacier National Park is the result of glacial erosion as well as post-glacial mass wasting processes. Debris flow magnitude and frequency have been established through extensive fieldwork across seven separate drainage basins in the eastern portion of the park. This paper summarizes the investigation of the hypotheses that debris flow distribution in the Glacier National Park, east of the Continental Divide is （a） not random; and Co） concentrated adjacent to the Continental Divide. The location of 2317 debris flows were identified and mapped from sixty-three 1-m resolution Digital Orthophoto Quarter Quadrangles and their spatial distribution was then analyzed using ArcView Spatial Analyst GIS software. The GIS analysis showed that the debris flows are not randomly distributed nor are they concentrated directly adjacent to the Divide. While the Continental Divide provides orographic enhancement of precipitation directly adjacent to the Divide, the debris flows are not concentrated there due to a lack of available weathered regolith. The most recent Little Ice Age glaciation removed the debris directly adjacent to the Divide, and without an adequate debris supply, these steep slopes experience few debris flows. Both abundant water and an adequate debris supply are necessary to initiate slope failure, resulting in a clustering of debris flows at the break in slope where valley walls contact talus slopes. A variety of summer storm and antecedent moisture conditions initiate slope failures in the Glacier National Park, with no distinct meteorological threshold. With over two million visitorsevery year, and millions of dollars of park infrastructure at risk, identifying the hazard of debris flows is essential to future park management plans.     

近百年海螺沟冰川退缩区域土壤CO2排放规律

贡嘎山东坡海螺沟冰川退缩地植被原生演替系列的样地调查基础上,用光合作用测定仪(美国产CI-301PS)的闭路方法测定土壤呼吸,并测定相关的生态因子。对植被原生演替过程中草本群落,川滇柳,冬瓜杨小树林,冬瓜杨中龄林,冬瓜杨成熟林,针阔混交林,云冷杉中龄林和云冷杉成熟林7个阶段的土壤呼吸速率进行连续3a的测定,它们的土壤CO2排放通量分别是51 67、39 70、56 45、58 89、85 22、120 26和158 65kgCO2/hm2·d-1。建立了7个阶段的土壤呼吸速率与温度的相关关系,认为未来大气温度升高将对同一气候区内的草地土壤呼吸影响最大,对演替过程中的落叶阔叶林土壤呼吸影响次之,对云冷杉林土壤呼吸影响最小。样地的形成年龄、生物量和净初级生产力这些与演替进程植物群落新陈代谢水平呈正相关的因素,才是决定样地土壤呼吸速率的主要因素,也是各样地之间土壤呼吸速率存在差异的主要原因。并将植被原生演替序列土壤CO2排放通量与国内外测定不同类型土壤呼吸速率的结果进行比较,认为Raich等人对温带针叶林土壤排放CO2通量的估测值偏低,对全球不同生态系统类型土壤排放CO2通量的差异估测不足。     

Application of UAV equipped with high resolution sensors in fine topographic mapping北大核心CSCD

无人机搭载高分辨率传感器,获取的正射影像和数字表面模型(DSM),能够很好的反映精细地形表面特征。本文以藏东南地区雅弄冰川末端为研究区,利用M300 RTK无人机搭配睿铂M6P量测型相机,获得了地面分辨率为1.5 cm的正射影像及DSM。与航天遥感数据Planet影像和数字高程模型TanDEM相比,无人机航测获取的正射影像、DSM在提取冰川边界、冰川表面形态上具有较大优势。本文利用坡度阈值法、R成像波段阈值法,能够有效提取冰裂隙、冰面湖的分布,且自动提取误差小于10%。因此,无人机航测获取冰川区精细地形在未来冰川研究中具有非常大的潜力,尤其是提取冰面特殊形态,研究微尺度地形对冰川变化的影响。     

可可西里马兰山冰川的近期变化

位于可可西里地区的马兰山冰帽，冰川覆盖了整个山体，冰川面积达195km^2，属极大陆型冰川，雪线海拔在5340－5540m之间，大多数冰川末端存在小冰期的碛垄，一般可分辨出3道，自小冰期以来，随着气候的变化，马兰山冰帽表现出波动退缩趋势。小冰期时，冰舌末端南坡比现在低20m，北坡低20－40m，由冰川退缩引起的冰川面积的减小相当于现代冰川面积的4．6％，略小于整个羌塘高原地区小冰期以来冰川面积减小的幅度（8％）。近百年来，冰川的退缩量为45－60m左右，而从1970年以来的30a中，马兰山冰川的退缩量为30－50m，平均年退缩量为1－1．7m。虽然小于高原边缘和其它地区冰川退缩幅度，但是退缩速率正在逐渐增大，这将对高原内陆脆弱的生态系统和生态环境产生较大的影响。