Paleoearthquakes in the Uimon basin (Gorny Altai)     

E.V. Deev  I.D. Zol’nikov  I.V. Turova  G.G. Rusanov  Yu.M. Ryapolova  N.N. Nevedrova  S.A. Kotler 《Russian Geology and Geophysics》2018,59(4):351-362

Paleoseismological studies confirm that the Uimon basin is thrust by its northern mountain border along the active South Terekta fault. The latest motion along the fault in the 7-8th centuries AD induced an earthquake with a magnitude of M_w= 7.4-7.7 and a shaking intensity of I = 9-11 on the MSK-64 scale. The same fault generated another event (M > 7, I = 9-10), possibly, about 16 kyr ago, which triggered gravity sliding. The rockslide dammed the Uimon valley and produced a lake, where lacustrine deposition began about 14 ± 1 kyr ago, and a later M > 7 (I = 9-10) earthquake at ~ 6 ka caused the dam collapse and the lake drainage. Traces of much older earthquakes that occurred within the Uimon basin are detectable from secondary deformation structures (seismites) in soft sediments deposited during the drainage of a Late Pleistocene ice-dammed lake between 100 and 90 ka and in ~ 77 ka alluvium. The magnitude and intensity of these paleoearthquakes were at least M > 5.0-5.5 and I > 6-7.  相似文献   

面向大规模空间Agent建模的分布式地理模拟框架     

曾梦熊  华一新  张政  张江水  杨振凯  韦原原 《地球信息科学学报》2022,24(5):815-826

基于Agent建模的地理模拟是认识和理解动态地理现象的有效方法,但随着地理模拟的规模和复杂性不断增加,模型的计算问题开始凸显。分布式并行仿真是解决大规模Agent复杂模拟计算的途径,然而已有研究基于Agent建模/仿真软件构建并行仿真系统的方式并不适用于具有高移动与行为交互的空间Agent建模及其模拟过程的实时可视化。为解决这个问题, 本文提出了一个分布式地理模拟框架DGSimF,用于大规模动态空间Agent模拟,支持模拟过程的实时表示与分析。设计了一个简单但高效的时空数据模型建模空间Agent,支持直接基于Agent行为建模集成地学模型,采用了时间微分方法协同各计算节点行为的执行,实现以“任务并行”的方式进行分布式计算以提高仿真性能,构建了基于三维地球渲染引擎的虚拟地理环境,提供模拟过程的实时可视化。最后,以“红蓝对抗”案例进行了实验验证,对不同模拟计算量和不同客户端数量下的仿真性能进行了分析,结果表明DGSimF可以为具有时空特征变化与行为交互的大规模空间Agent模拟提供一个有效的平台。通过扩展计算节点,DGSimF可以有效地缓解复杂模拟计算的压力问题,并且仿真性能较高,在实验中并行效率保持在0.7以上。  相似文献   

基于影响因子动态更新的都市圈国土-人口协同模拟     

高位  涂伟  李明晓  方碧宸  陈栋胜  黄正东  贺彪 《地球信息科学学报》2022,24(8):1502-1511

都市圈作为典型的复杂巨系统,其国土、人口、交通等要素呈现出共同演化、协同发展的特征。现有基于元胞自动机的空间模拟方法通常分别进行国土或人口模拟,忽略了国土、人口之间的协同演化,从而限制了模拟性能。本文提出一种影响因子动态更新策略用以表征国土、人口两种要素间的相互作用,拓展经典元胞自动机模型构建协同模拟算法,实现了都市圈国土与人口空间分布态势的精准模拟。本文以深莞惠都市圈为例,对提出算法进行了实验验证。实验结果表明,本文提出协同模拟算法在深莞惠都市圈的国土模拟品质因素为0.274、人口模拟平均绝对百分比误差23.55%,分别优于传统基于随机森林的元胞自动机算法0.24和29.33%;相较于传统模型,在国土模拟中本模型在对于建设用地的模拟准确度提升了约3%,在人口模拟中本模型在对人口高密度的区域模拟误差降低了约6%。本文进一步预测了深莞惠都市圈2030年国土和人口发展空间态势。研究结果可为都市圈重大基础设施选址和发展情景推演提供技术支撑。  相似文献   

Effect of Penetration Rates on the Piezocone Penetration Test in the Yellow River Delta Silt     

ZHANG Jiarui  MENG Qingsheng  ZHANG Yan  FENG Xiuli  WEI Guanli  SU Xiuting  LIU Tao 《中国海洋大学学报(英文版)》2022,21(2):361-374

Partial drainage often occurs during piezocone penetration testing on Yellow River Delta silt because of its intermediate physical and mechanical properties between those of sand and clay.Yet,there is no accurate understanding for the range of penetra-tion rates to trigger the partial drainage of silt soils.In order to fully investigate cone penetration rate effects under partial drainage condi-tions,indoor 1 g penetration model tests and numerical simulations of cavity expansion at variable penetration rates were carried out on the Yellow River Delta silt.The boundary effect of the model tests and the variation of key parameters at the different cavity ex-pansion rates were analyzed.The 1 g penetration model test results and numerical simulations results consistently indicated that the penetration rate to trigger the partially drainage of typical silt varied at least three orders of magnitude.The numerical simulations also provide the reference values for the penetration resistance corresponding to zero dilation and zero viscosity at any given normalized penetration rate for silt in Yellow River Delta.These geotechnical properties can be used for the design of offshore platforms in Yel-low River Delta,and the understanding of cone penetration rate effects under the partially drained conditions would provide some technical support for geohazard evaluation of offshore platforms.  相似文献   

DInSAR技术对不同方位形变的敏感性研究   总被引：3，自引：1，他引：2  

查显杰  傅容珊  戴志阳 《测绘学报》2006,35(2):133-137

以DEM数据为假想的地面目标,只考虑距离对相位的影响,模拟竖直向、距离向和方位向形变的干涉纹图,从而研究DInSAR技术对空间不同方位形变的敏感性。在所有模拟参数和形变位移大小都相同的情况下,三个不同方位形变所产生的相位从0到2π变化的完整干涉环的数目是各不相同的,揭示DInSAR技术对不同方位地表形变的敏感性存在差异,且敏感性由大到小依次为:竖直向、距离向和方位向。  相似文献   

Comprehensive Marine Observing Experiment Based on High-Altitude Large Unmanned Aerial Vehicle(South China Sea Experiment2020 of the “Petrel Project”)     

Xuefen ZHANG  Liangxu LI  Rongkang YANG  Ran GUO  Xia SUN  Jianping LUO  Hongbin CHEN  Daxin LIU  Kebing TANG  Wenwu PENG  Xiaodong HAN  Qiyun GUO  Xiaoxia LI  Xikun FEI 《大气科学进展》2021,38(4):531-537

In collaboration with 12 other institutions, the Meteorological Observation Center of the China Meteorological Administration undertook a comprehensive marine observation experiment in the South China Sea using the Yilong-10 high-altitude large unmanned aerial vehicle(UAV). The Yilong-10 UAV carried a self-developed dropsonde system and a millimeter-wave cloud radar system. In addition, a solar-powered unmanned surface vessel and two drifting buoys were used. The experiment was further supported by an intelligent, reciprocating horizontal drifting radiosonde system that was deployed from the Sansha Meteorological Observing Station, with the intent of producing a stereoscopic observation over the South China Sea. Comprehensive three-dimensional observations were collected using the system from 31 July to2 August, 2020. This information was used to investigate the formation and development processes of Typhoon Sinlaku(2020). The data contain measurements of 21 oceanic and meteorological parameters acquired by the five devices, along with video footage from the UAV. The data proved very helpful in determining the actual location and intensity of Typhoon Sinlaku(2020). The experiment demonstrates the feasibility of using a high-altitude, large UAV to fill in the gaps between operational meteorological observations of marine areas and typhoons near China, and marks a milestone for the use of such data for analyzing the structure and impact of a typhoon in the South China Sea. It also demonstrates the potential for establishing operational UAV meteorological observing systems in the future, and the assimilation of such data into numerical weather prediction models.  相似文献   

川贵渝复杂地形下横槽诱发双涡贵州暴雨过程的数值模拟     

程晓龙  李跃清  衡志炜 《气象学报》2021,79(4):626-645

青藏高原大地形作用下,西南复杂地形区暴雨天气预报是一个十分重要和困难的科学问题。应用西南区域数值预报业务模式,结合业务常规观测和非常规观测资料,分析了2014年7月15日至17日发生在四川、贵州和重庆复杂地形下的一次由横槽诱发双低涡的贵州暴雨过程,得到:西南区域模式对这次暴雨过程的数值模拟结果与再分析资料有较好的对应关系,尤其是重现了降雨的落区、强度以及盆地涡与贵州涡的发生、发展过程。在暴雨过程中,两低涡垂直发展深厚,上升运动均伸展至对流层顶。涡度收支方面,盆地涡的发展主要源于涡度方程的散度项,而贵州涡的发展除了受散度项的显著影响外,平流项也起着重要作用。由于川渝盆地—云贵高原交界处地形、云贵高原横断山脉延伸区局地地形的作用,区域大气气旋式旋转的加强发展诱发了盆地涡和贵州涡。热力结构上,盆地涡的发生、发展在冷、暖气流交汇辐合区域内,而贵州涡则生成在暖区中,其降雨及加强更多地受到动力过程的影响。川渝盆地—云贵高原特殊的北低南高地形使高纬度干冷气流与低纬度暖湿气流交汇,形成强的上升运动,引发了盆地涡发展及其暴雨天气。云贵高原贵州特殊的西高东低地形导致来自低层的暖湿气流只能沿横断山脉边缘绕流,进入贵州西部的偏南气流与来自盆地涡西侧的偏东北气流汇合作用形成贵州涡,引发贵州暴雨天气。因此,局地地形与环流的相互作用是贵州涡生成及其引发暴雨过程的重要原因。   相似文献   

基于ENVI-met的福州大学校区冬季热环境模拟与热舒适度变化分析     

庄莉娟  蔡芫镔  祁娟娟 《气象与环境学报》2021,37(6):44-52

选取福州大学校园教学区为研究区域,基于典型冬季日背景,运用三维非静力微气候模型ENVI-met,分析模拟校园热环境的差异变化及其热舒适度响应。结合实地勘测,对模型进行校准和验证。结果表明：ENVI-met模型能较好地表征室外热环境,准确预测温度和相对湿度的日变化趋势。混凝土路面、灰色地砖路面行人高度的日平均气温分别比草地高出0.1 ℃和0.3 ℃,逐时最大温差分别为0.68 ℃和0.65 ℃。建筑物阴影和树阴可降低行人高度的气温1.1—1.9 ℃;同一组团在有无遮阴的条件下,平均辐射温度（T_mrt）相差最大可达30 ℃;树木附近和建筑物组团内部生理等效温度（PET）值较小,比硬质路面低2—3个等级。无植被方案下,高温低湿区范围有所扩张,在垂直方向上的增温效应可伸展至10.5 m;风速最大增幅可达1.23 m·s^-1,平均辐射温度较高区域的面积增加了69.25%;热舒适区和热不适区面积分别增加了19.78%和2.03%。  相似文献   

中国长三角地区PM2.5时空分布数值模拟研究     

许敏 《气象与环境学报》2021,37(4):33-39

利用第三代空气质量预报模式LOTOS-EUROS(Long Term Ozone Simulation-European Operational Smog)对2018年中国长三角地区细颗粒物(PM_2.5)浓度的时空分布进行数值模拟,通过对比模拟结果与地面观测值,验证模式对PM_2.5长期特征模拟的合理性并探讨长三角地区PM_2.5的时空分布特征。结果表明：LOTOS-EUROS模式可以较好地再现中国长三角地区PM_2.5浓度的时空分布特征,监测站点观测值和模拟值的整体相关系数达到0.64,可以用于长三角地区细颗粒物的模拟。长三角地区PM_2.5浓度呈冬高夏低,西北高东南低的特征。冬季PM_2.5浓度高值出现在长三角地区的西北部,安徽省等地区的浓度水平最大值可达到160 μg·m^-3;春季和秋季PM_2.5浓度的高值集中在30°N以北、120°E以西地区,浓度为40-80 μg·m^-3;而夏季PM_2.5浓度水平大幅度降低,大部分地区维持在20-40 μg·m^-3,低值中心出现在长三角地区东南部沿海城市,低于10 μg·m^-3,最低值可达5 μg·m^-3。  相似文献   

Influence of the quality factor on simulated seismic waves: A case study of the 1994 Northridge earthquake          下载免费PDF全文

Qingpei Zeng  Xiangchao Wang  Jinting Wang 《地震科学（英文版）》2022,35(5):329-342

In numerical simulations of ground motion, the constant quality factor Q of a viscoelastic medium can be determined using the time-domain constitutive approximation method of the generalized standard linear solid (GSLS) model. This study introduces a numerical seismic wavefield simulation method which combines the spectral element method with the constant-Q model. The method is used to simulate the seismic wavefield of the 1994 Northridge earthquake. The optimal attenuation coefficient for the simulated seismic waves in this study area is determined empirically based on a quantitative analysis of the deviation curve. Further, the effect of the quality factor on the simulated wavefield are analyzed according to the site characteristics of each seismic station. The quality factor shows a variable effect on the different frequency components of the simulated wavefield. The effect of the quality factor also varies with the characteristic parameters of each seismic station site, such as site velocity structure, fault distance, and azimuth angle.  相似文献