The Calculation Method for the Volume of Landslides and Dammed Lake Sediments Triggered by a Strong Historical Earthquake in the Loess Plateau: A Case Study of Qiuzigou, Gansu Province, Northwest China     

DU Peng  XU Yueren  LI Wenqiao  TIAN Qinjian  CHEN Lize 《中国地震研究》2020,34(4):580-598

The quantitative calculation of the volume of large earthquake-triggered landslides and related dammed lake sediments is of great significance in the study of secondary disasters and focal parameters of strong historical earthquakes. In this study, the dammed lake induced by Qishan M7 earthquake (Lingtai County, Gansu Province, Northwest China) is selected as the research object. Based on the information collected from the 4 boreholes in the dammed lake area, we further take advantage of the low-level Unmanned Aerial Vehicle (UAV) photogrammetry and the morphology recovery method,to calculate the volume of the dammed lake and landslides, respectively. Finally, major conclusions are obtained as follows:① the AMS-¹⁴C age at the bottom of the Qiuzigou Dammed Lake sediments is 2 890±30 BP, which coincides with the 780 BC Qishan earthquake; furthermore, the Qiuzigou Landslides seem to have been triggered by the earthquake, forming an enclosed dammed lake deposition environment after the upstream sediments accumulate;② the Qiuzigou landslides are opposite-sliding landslides that have blocked the river valley; in detail, landslide volumes at the right and left banks are 235×10⁴ m³ and 229×10⁴ m³, respectively. The length of the dammed lake is 2.6 km, with a thickness of approximately 43 m near the landslides, and the total sedimentary volume is 573×10⁴ m³; ③the erosion rate of Qiuzigou Landslide Dammed Lake is 0.44 mm/a, the accumulation rate is 15.05 mm/a, and the soil erosion modulus is 593 t/(km²/a), characterized as slight erosion. Quantitative research on the formation of landslides and dammed lakes from strong historical earthquakes is vital for increasing our understanding of the vibrational characteristics and surface action processes of these types of earthquakes.  相似文献   

内蒙古高原等地湖泊表层沉积物孢粉与植被覆盖度定量关系研究          下载免费PDF全文

陈东雪  王维  刘立娜  姜亚娟  李岩岩  牛志梅  马玉贞  何江 《干旱区地理》2019,42(5):1011-1022

过去植被覆盖度重建在长尺度气候模拟和陆地生态环境演变机制研究等方面具有重要意义。基于现代过程的孢粉—植被覆盖度转换函数研究,可为利用孢粉地层数据重建过去植被覆盖度变化提供一条新的途径。以内蒙古高原等地39个湖泊和7个水库中心的表层沉积物孢粉组合与归一化植被指数(NDVI)为研究对象,利用加权平均偏最小二乘法(WA-PLS)、局部加权加权平均法(LWWA)和最佳类比法(MAT)分别建立了孢粉—NDVI转换函数;通过留一交叉检验法、自助法和空间自相关性等检验,筛选出最优模型并应用于古地层孢粉数据,实现定量重建过去植被覆盖度变化。结果表明:MAT和WA-PLS模型均受到空间自相关性的显著影响,而LWWA模型则是建立孢粉—NDVI转换函数的最优模型。与已有类似转换函数表现能力的对比表明,本研究建立的转换函数具有较强的可靠性和应用潜力。基于本研究转换函数重建的内蒙古辉腾锡勒(HTL)区域全新世植被覆盖变化与孢粉重建的植被变化具有很好的一致性,进一步印证了本研究转换函数的较强潜力,均表现出对降水变化的响应更为显著。  相似文献   

Modelling Chorabari Lake outburst flood,Kedarnath, India     

Mohammd RAFIQ  Shakil Ahmad ROMSHOO  Anoop Kumar MISHRA  Faizan JALAL 《山地科学学报》2019,(1):64-76

In this study, the Glacier Lake Outburst Flood(GLOF) that occurred over Kedarnath in June 2013 was modeled using integrated observations from the field and Remote Sensing(RS). The lake breach parameters such as area, depth, breach, and height have been estimated from the field observations and Remote Sensing(RS) data. A number of modelling approaches, including Snow Melt Runoff Model(SRM), Modified Single Flow model(MSF), Watershed Management System(WMS), Simplified Dam Breach Model(SMPDBK) and BREACH were used to model the GLOF. Estimations from SRM produced a runoff of about 22.7 m3 during 16–17, June 2013 over Chorabari Lake. Bathymetry data reported that the lake got filled to its maximum capacity(3822.7 m3) due to excess discharge. Hydrograph obtained from the BREACH model revealed a peak discharge of about 1699 m3/s during an intense water flow episode that lasted for 10–15 minutes on 17 th June 2013. Excess discharge from heavy rainfall and snowmelt into the lake increased its hydrostatic pressure and the lake breached cataclysmically.  相似文献   

基于3S技术方法的中国冰湖编目   总被引：1，自引：0，他引：1  

杨成德  王欣  魏俊峰  刘琼欢  鲁安新  张勇  唐志光 《地理学报》2019,74(3):544-556

通过研制一整套基于3S技术的冰湖编目规范与方法,以159景Landsat8 OLI遥感影像为基础,结合中国第二次冰川编目数据与Google Earth中的影像数据等,通过人工目视解译获取冰湖边界,首次完成了基于统一规范的中国冰湖编目数据库建设,查清了2015±1~2年中国冰湖的整体分布状态。结果显示,当前中国共有冰湖17300个,总面积1132.83±147.449 km²,其中冰川补给湖约占中国冰湖总面积的74.6%和总数量的66.5%。并且冰湖数量与面积分布的空间差异十分显著。流域上,外流区冰湖广泛发育,其中恒河—雅鲁藏布江流域是中国冰湖分布最多的流域,现有冰湖7898个,面积约622.42±75.55 km²,分别占中国冰湖总量的45.7%和54.9%;海拔上,中国冰湖分布于2167~6247 m的海拔范围内,各山脉的冰湖面积呈近似正态分布,总体在5000~5500 m处达到峰值,占总面积的36.7%（975.06±128.83 km²）;但各个山脉的分布差异显著,其中念青唐古拉山、喜马拉雅山的冰湖分布最为集中,分别占中国冰湖总面积的28.3%和26.4%。  相似文献   

溶液化学专刊     

庞登科 《盐湖研究》2019,27(1)

The present work are extract cesium (Cs_⁺) and rubidium (Rb_⁺) from the salt lake brine containing the potassium (K_⁺) and magnesium (Mg_²⁺) after concentrated through evaporation. It has excellent effect of extraction that 4-sec-butyl-2-(α-methylbenzyl) phenol (t-BAMBP) was diluted in the Sulfonated Kerosene (SK). The infrared spectrum studies indicate that polymerize to form the dimer in the t-BAMBP when Cs_⁺ or Rb_⁺ were extracted. The effect of K_⁺ and Mg_²⁺, t-BAMBP concentration, the volume ratio of organic phase to aqueous phase (O/A) and the alkalinity(pH) of aqueous phase were investigated. The K_⁺ and Mg_²⁺ should be eliminated through precipitation before extraction and separation Cs_⁺ and Rb_⁺. The experimental brine was extracted of optimum conditions were using 0.8 mol/L t-BAMBP in SK, the pH exceed 13, and O/A of 1:1 for 2 min contact time under room temperature. The optimal extraction yields of Cs_⁺ and Rb_⁺ up to 100% and 85.8%, and 8.76% K_⁺ was co-extracted. Further work target to increase theSextractionSyield and selectivity ofSRb_⁺, and realize the efficient seperation of Cs_⁺ and Rb_⁺ products .  相似文献   

Influence of the regional climate variations on lake changes of Zabuye,Dangqiong Co and Bankog Co salt lakes in Tibet     

Wang  Yunsheng  Zheng  Mianping  Yan  Lijuan  Bu  Lingzhong  Qi  Wen 《地理学报(英文版)》2019,29(11):1895-1907

Journal of Geographical Sciences - The lake hydrological and meteorological data of the Tibetan Plateau are not rich. This research reports the observed climatic data and measured water levels of...  相似文献   

Stable climatic conditions in central Germany during the last interglacial     

Tatjana Boettger  Frank W. Junge  Thomas Litt 《第四纪科学杂志》2000,15(5):469-473

  相似文献   

1990—2021年东太湖网围养殖规模变化下的水质变化特征及成因分析     

李一凡  谷孝鸿  曾庆飞  贾冰婵  訾鑫源  陈辉辉  毛志刚  葛优 《湖泊科学》2023,35(1):155-167

2019年,东太湖30 km2养殖网围实现清零,结束了长达34年的太湖网围养殖历史。系统整理东太湖30年来(1990 2021年)水体氮、磷等营养盐浓度监测资料,对比分析14个监测点位水质在不同网围利用和整治时期的时空差异性及影响因素,判识网围拆除后水体营养盐变化趋势及存在问题对东太湖生态修复与保护具有重要意义。结果表明,东太湖30年来水体营养盐浓度年际变化随养殖结构(主养鱼到主养蟹)和养殖规模(过度利用到网围整治和拆除)的变化而变化,网围养蟹因其有效的水生植物管控和生态混养相对于主养鱼类水质较优,但水质均随着养殖强度的增大而变差,网围规模缩减对改善水质有正面效应。总氮(TN)、总磷(TP)、高锰酸盐指数(COD_Mn)和叶绿素a(Chl.a)浓度分别由1990年的0.53 mg/L、0.014 mg/L、3.58 mg/L和2.90μg/L上升到2021年的1.87 mg/L、0.128 mg/L、5.72 mg/L和28.09μg/L,TN是主要的污染因子。原网围区和湖心区因较高的水生植被覆盖度,TN、TP、磷酸盐、悬浮颗粒物(SS)30年来变化不大,原网围区透...  相似文献   

从涨退水看鄱阳湖水位-湖面面积关系   总被引：1，自引：0，他引：1  

曾少龙  赖格英  杨涛 《水文》2019,39(3):46-51

鄱阳湖是我国最大的淡水湖,鄱阳湖水位-面积关系对研究鄱阳湖生态环境的变化具有重要意义。目前研究所建立的鄱阳湖水位-面积关系各异,存在一定的不确定性,其原因在于忽略了涨退水对鄱阳湖水位与面积的影响。在考虑鄱阳湖涨水与退水过程的基础上,利用鄱阳湖2000~2014年实测水位数据与对应的遥感影像数据,分析了鄱阳湖同一水位出现多个水面面积情况下湖泊不同面积的空间分布及其成因,并对鄱阳湖水面面积与水位关系的不确定性进行了分析。研究结果表明:(1)鄱阳湖水面面积与水位关系存在不确定性,主要受鄱阳湖涨水与退水过程中鄱阳湖水面比降不同的影响;(2)在同一水位条件下,涨水过程中鄱阳湖水面面积往往大于退水过程的水面面积,同时水面面积的增减变化与涨水退水的幅度变化趋势呈一致性;(3)涨水与退水过程对鄱阳湖水位与面积的影响主要表现在中低水位,随着水位增长到高水位时,这种影响会越来越小。  相似文献   

尾砂胶结含盐冻结充填体力学特性研究     

吴再海  纪洪广  姜海强  齐兆军  寇云鹏 《岩土力学》2020,41(6):1874-1880

矿山充填开采正逐步向寒区甚至永久冻土区发展,这些区域含盐地下水分布非常广泛。同时,极端寒冷条件下往往需要向充填材料中加入一些防冻盐以防止料浆在输送过程中发生冻结。通过室内测试分析了?6 ℃环境下不同盐分（NaCl）膏体充填体力学特性（强度和初始弹性模型）随时间演化特征。利用单轴压力机测得了龄期为7、28、90 d膏体充填体的强度和初始弹性模量,结果表明NaCl的加入会降低冻结充填体的强度,其影响程度取决于胶结料类型。试样的强度随着养护时间的增加而增大。此外,不论盐分浓度、养护时间和胶结料类型,试样的强度与初始弹性模量之间存在显著的线性关系。该研究结果可以为寒区含盐膏体充填技术的开展提供一些依据。  相似文献