Ice surface-elevation change and velocity of Qingbingtan glacier No.72 in the Tomor region, Tianshan Mountains, central Asia

Glaciers in the Tomor region of Tianshan Mountains preserve vital water resources.However,these glaciers suffer from strong mass losses in the recent years because of global warming.From 2008 to 2009,a large-scale scientific expedition has been carried out in this region.As an individual reference glacier,the tongue area of Qingbingtan glacier No.72 was measured by the high precise Real Time Kinematic-Global Position System (RTK-GPS).In this paper,changes of the tongue area of Qingbingtan glacier No.72 has been studied based on topographic map,remote sensing image and the survey during 2008-2009 field campaign.Results indicated that the ice surface-elevation of the tongue area changed-0.22±0.14 m a-1 from 1964 to 2008.The estimated loss in ice volume was 0.014±0.009 km3,which represented a ～20 % decrease from the 1964 volume and was equivalent to average annual mass balance of-0.20±0.12 m water equivalent for the tongue area during 1964-2008.Terminus retreated by 1852 m,approximately 41 m a-1,with the area reduction of 1.533 km2 (0.034 km2 a-1) from 1964 to 2009.Furthermore,the annual velocity reached to ～70 m a-1.Comparing with the other monitored glaciers in the eastern Tianshan Mountains,Qingbingtan glacier No.72 experienced more intensive in shrinkage,which resulted from the combined effects of climate change and glacier dynamic,providing evidence of the response to climatic warming.     

Enhancing dispersion of halloysite nanotubes via chemical modification

Uniform and dispersed halloysite nanotubes (HNTs) were obtained using sodium dodecyl sulfate (SDS) to disperse the halloysite suspension. The dispersed HNTs were characterized by X-ray diffraction, scanning electron microscope, energy-dispersive spectrometry, transmission electron microscope, Fourier transform infrared spectroscopy, thermogravimetry–differential scanning calorimetry and zeta potential. The results indicated that SDS was adsorbed and scattered on the HNTs, which could enhance the stability and dispersibility of suspension by the electrostatic effect. The zeta potential of dispersed HNTs became larger than that of the raw within the pH ranging from 2.5 to 11.9, which reached ?31 mV at pH around 8 when the concentration of SDS was 1.22 g/L. The diameter of dispersed HNTs ranged from 0.6 to 1.2 μm. A corresponding dispersive mechanism was investigated.     

杭州市高温致灾因子危险性风险区划

利用杭州市各气象观测站和自动气象站多年气温资料,以及数理统计方法和Arc GIS空间分析技术,采用极端高温与高温日数作为高温致灾因子风险的主要评价指标,分析杭州市高温天气的气候特征,对杭州市高温灾害致灾因子危险性进行了区划。结果表明,杭州市高温天气灾害较为严重,常出现38.0℃以上的高温,40.0℃以上也不少见,最高达到42.9℃;高温日数较长,最长持续时间超过50 d。杭州市高温灾害危险性风险高值区大部分集中在杭州城区所在的东北部平原,包括上城区、下城区、拱墅区、江干区、滨江区、西湖区西南部、萧山区及余杭区大部。另外,富春江、分水江等沿江两岸,西南部的河谷、盆地以及中部地势较复杂的谷地、盆地等低海拔地区也处于高温危险性中高值区域;北部天目山、西北部昱岭及白际山、西南部千里岗山及龙门山脉高海拔地区均属于危险性风险低值区域。     

Response of the Melting Urumqi Glacier No. 1 in Eastern Tianshan to Climate Change

 Current glacier recession under the global warming has aroused world-wide attention. Initiated from 1958, the observations of Urumqi Glacier No. 1 at the headwaters of Urumqi River in eastern Tianshan promise the best datasets of the glacier and the climate changes in China. Taking Urumqi Glacier No. 1 as an example, we analyzed the response of the glacier to the climate change. The results show that over the past 50 years, the glacier has changed remarkably in the aspects of snow-firn stratigraphy, ice formation zone, ice temperature, area and terminus position, etc. These changes are apparently the results of temperature rise in this area. The glacier recession continued throughout the entire observed time period, and showed an accelerated tendency since 1985. Meltwater runoff also increased 84.2% over the last 20 years.     

基于WebGIS的城市公厕信息管理服务的研究

结合武汉市公众导厕与管理系统,讨论了公众导厕与管理系统的平台设计和技术路线选择,阐述了地图予处理、JavaScript地图库引用等关键技术,论述了栽图模块和地图位置算法设计。     

最新的岩石圈磁场模型及中国磁异常特征的几点认识

介绍了最新的地球磁场模型,包括MF5,NGDC-720和WDMAM。模型MF5是由CHAMP卫星测量得来,它的球谐展开阶次为n=16~100,对应的波长段为400~2500km。模型NGDC-720和WDMAM是综合了卫星磁测、航空磁测、海洋磁测与地面磁测得到数据经过处理后得来,它们有不同的球谐阶次和分辨率。NGDC-720模型是由美国国家地球物理数据中心(The National Geophysical Data Center,NGDC)提供,它的球谐阶次从16阶到720阶,对应于由2500km到56km的波带。M.Purucker博士公布的WDMAM参考模型1是一张分辨率为3′,高度位于WGS84上方5km的磁异常图,它向上延拓后的结果与MF5中的岩石圈磁异常保持一致。作者根据国际上公布的CHAMP、NGDC-720与WDMAM Candidate1的最新数据,绘制了中国及毗邻地区的磁异常图,对中国及毗邻地区明显的大地构造,如造山带,盆地等地区的磁异常特征进行了描述和分析,塔里木、四川、松辽等盆地地区及华北平原部分地区模型中均表现为正异常,西藏高原、天山造山带等地区表现为负异常,而一些深大断裂表现为磁异常高梯度带。通过四川盆地和西藏高原地区三个模型的相互对比,我们发现模型阶次越高,它所反映的磁性体(尤其是浅部地质体)的情况越丰富,不同的是四川盆地的结果随着阶次的增高就越接近航磁结果,而西藏高原随着阶次的增高却和航磁结果差别越来越大。     

低山丘陵区典型滑坡-泥石流链生灾害特征与成灾机理

2019年6月10—13日,龙川县发生持续强降雨,导致全县境内发生大量滑坡、泥石流灾害,贝岭镇米贝村是三个重灾区之一。本文以贝岭镇米贝村6号沟发生的滑坡-泥石流链生灾害为研究对象,在野外精细化调查测量基础上,结合数值模拟分析与计算,对链生灾害特征与成灾机理展开研究。研究发现:①6号沟内共发育7处浅层土质小型滑坡,仅3号滑坡体与部分6号滑坡体转化为泥石流,构成泥石流主要物源,其余滑坡未构成持续性影响;②持续降雨下渗,坡体由非饱和向饱和状态转变,坡表形成连续饱和区,孔隙水压力的增加与孔隙水的软化促使土体强度降低,加之坡体饱和自重的增大,斜坡发生浅表层失稳破坏;③降雨的持续下渗与支沟沟源“漏斗状”地形下的地表汇水快速增大滑坡松散堆积体内的含水率,促使其物理性质发生变化,在重力势能下呈流态状启动、运动转化为泥石流。降雨结构影响滑坡-泥石流链生过程,前期降雨引发滑坡、后期降雨启动形成泥石流,滑坡与泥石流的发生表现出阶段性特征。研究成果有助于指导当地政府进一步开展滑坡-泥石流链生灾害的防灾减灾工作,也为该地区未来区域预警研究工作提供理论支撑。     

四川省甘洛县泥石流

甘洛县泥石流活动十分活跃,曾造成摧毁场镇、冲毁桥梁、颠覆列车、淤埋农田等严重灾害。据现有资料,该县有泥石流沟50条,主要分布在断裂带两侧、背斜轴部和河流峡谷段。预防措施是结合农业改革,恢复森林生态系统和合理开发地下矿藏;治理措施是生物与工程相结合,拦挡与排导相结合进行综合治理。     

贵州麻山地区居民的资源环境意识模糊综合评价

用模糊综合评价方法,根据实地抽样调查的统计资料,对麻山地区居民的资源环境意识用定性定量的分析。得出该区环境恶化的主要原因是资源环境意识差,居民自觉或不自觉地破坏生态环境以资源为代价,来满足不断增长的人口的需求。     

Biotic characteristics of the Sinian-Cambrian boundary beds in China and the boundary problems

There is general agreement that the first appearance of various small shelly fossils should be used to help delineate the beginning of the Cambrian Period. The history of research on this stratigraphic topic in China is briefly outlined and leads on to a discussion of the boundary problem in the light of information available both inside and outside China.The sections across the Precambrian—Cambrian (Sinian—Cambrian) boundary are described with notes on fossils in: (1) Tianzhushan section, Yichang, Hubei; (2) Maidiping section, Emli, Sichuan; (3) Wangjiawan section, Jinning County, Yunnan; and (4) Kunyang section, Yunnan.This is followed by a consideration of the biotic characteristics of Sinian—Cambrian Period. The history of research on this stratigraphic topic in China is briefly outlined and leads on to a discussion of the boundary problem in the light of information available both inside and outside China. This is followed by a consideration of the biotic characteristics of Sinian—Cambrian boundary beds, with respect to stratigraphy as well as organic evolution. The Precambrian—Cambrian boundary in China is estimated to have an age of 615 ± 20 Ma.It is commented that the above sections are qualified to be important candidates for the selection of the Sinian—Cambrian boundary stratotype and are also important working reference sections for the international Precambrian—Cambrian boundary stratotype.