Rapid zonation of abrupt mass movement hazard: Part I. General principles     

J.R. Ni  R.Z. Liu  Onyx W.H. Wai  Alistair G.L. Borthwick  X.D. Ge   《Geomorphology》2006,80(3-4):214-225

Hazards caused by mass movement cost many human lives and cause severe damage to property. Accurate zonation of such hazards provides an important tool for preventive measures. Previous approaches for mass movement hazard zonation are costly because they require large amounts of data, time and labor, and are only applicable to specific local areas. In this paper, a Rapid Zonation of Abrupt Mass-movement Hazard (RZAMH), applicable to large regions, is proposed. It involves the selection of appropriate zonation principles, routes, units, and indexes that can be used for the classification of reference groups, identification of matching groups of test sites, evaluation of blank test sites, and coalescence of sub-regions into specified zonation areas. The K-means clustering method is used in the classification processes. The applicability of the RZAMH approach to a large area implies that the number of reference sites required to build the reference groups is not of primary importance as long as the reference sites are representative. Therefore, for large areas, the RZAMH approach would be more economical than other conventional methods. The RZAMH approach is probably applicable to all abrupt mass movement hazards including rock falls, landslides, and debris flows.  相似文献   

The progression of flow rates in variable declining rate filter systems     

Wojciech Dabrowski 《洁净——土壤、空气、水》2006,34(5):442-452

It has been demonstrated that the mathematical model of variable declining rate filters developed by Di Bernardo may be described by (z + 1) non‐linear equations, where z is the number of filters in a bank. Three approximate solutions to this system of equations have been developed and then verified by comparison with numerical solution and published experimental data. Two of these solutions appeared to be very accurate, while the third showed higher, but still acceptable errors of calculation. According to this approximation, flow rates through filters are elements of a geometric progression.  相似文献   

谈谈“地震速报评比软件”及其研制     

李华  周峰嵘  郑黎辉  孙则兴 《福建地震》1998,(2)

本文介绍了“地震速报评比”的重要性及“地震速报评比”软件的研制及使用效果。认为用该软件进行速报评比可使评比结果更公正、准确,评比工作效率也可以大大提高。  相似文献   

广东沿海经济高速发展区人地系统可持续发展研究   总被引：3，自引：0，他引：3  

温琰茂  柯雄侃 《地理科学》1998,18(2):122-128

粤中沿海经济高速发展的典型区域－深圳市人地中系统持续性从１９８０￣１９９０年逐渐增加,但１９９１年开始下降;东莞市人地系统可持续性从１９８０年以后逐渐增强。目前深圳市和东莞市人地系统均处于弱可持续性状况。  相似文献   

伽玛能谱快速找金方法及其应用   总被引：1，自引：0，他引：1  

陈礼宽  胡兴凤 《江苏地质》1996,20(3):166-171

选用携带式微机伽玛能谱仪测定岩石，土壤中钠，钍，钾及其放射性总量，能定量或半定量地估算某些含金地质体中的含量。对新疆某地进行地面，井下测定，新发现金矿脉一条，金储量６２４ｋｇ；圈定４个金矿化段，２个富集金地段；验证评价２个综合化探晕圈，快速评价２个金矿区和８个金矿点；特别对井下预测金品位准确可靠，能及时指导矿区井下采掘。  相似文献   

Two-Point Properties Of Atmospheric Turbulence Very Close To The Ground: Comparison Of A High Resolution Les With Theoretical Models     

Pierre Carlotti 《Boundary-Layer Meteorology》2002,104(3):381-410

Using the tools of large-eddy simulation (LES), rapid distortion theory andEulerian kinematic simulation, two-point properties of turbulenceare studied. It is shown how the boundary conditions in thepresent LES model are fully consistent with the new top-down understanding ofatmospheric turbulence close to the ground, wherethe turbulence is analysed in terms of turbulent eddies impinging ontothe ground, being distorted by the shear and the blocking by the wall,and experiencing the creation of an internal boundary layer within aneddy surface layer (ESL) with a height of a dozen metres.The question of very large streamwise structures is addressed, and itis shown that the k^-1 range measured in spectra for the streamwisevelocity in the ESL in several recent field experiments can be found in LES, and corresponds to streaky structures. However, thesestreaky structures are different from the low Reynolds number streaks,which induce a k^-2 range in the spectrum. Finally, two-point verticalcorrelations are studied. In particular, effects of shear and of the slope of thespectrum are analysed.  相似文献   

CO2快速测定方法的应用研究   总被引：4，自引：0，他引：4  

高小其  王道  许秋龙  马飞虎  周俊  包志贤  李新勇  李艳萍 《内陆地震》2002,16(1):76-83

在新疆水磨沟形变站院内 ,布设了一个 CO2 快速测定法观测点。 2 0 0 1年 7月 4日呼图壁 MS3.9级地震前 ,在该观测点观测到了明显的短临异常  相似文献   

Sensitivity of tropical cyclone intensification to boundary layer and convective processes   总被引：1，自引：1，他引：1  

D. V. Bhaskar Rao  Dasari Hari Prasad 《Natural Hazards》2007,41(3):429-445

This study examines the role of the parameterization of convection, planetary boundary layer (PBL) and explicit moisture processes on tropical cyclone intensification. A high-resolution mesoscale model, National Center for Atmospheric Research (NCAR) model MM5, with two interactive nested domains at resolutions 90 km and 30 km was used to simulate the Orissa Super cyclone, the most intense Indian cyclone of the past century. The initial fields and time-varying boundary variables and sea surface temperatures were taken from the National Centers for Environmental Prediction (NCEP) (FNL) one-degree data set. Three categories of sensitivity experiments were conducted to examine the various schemes of PBL, convection and explicit moisture processes. The results show that the PBL processes play crucial roles in determining the intensity of the cyclone and that the scheme of Mellor-Yamada (MY) produces the strongest cyclone. The combination of the parameterization schemes of MY for planetary boundary layer, Kain-Fritsch2 for convection and Mixed-Phase for explicit moisture produced the best simulation in terms of intensity and track. The simulated cyclone produced a minimum sea level pressure of 930 hPa and a maximum wind of 65 m s⁻¹ as well as all of the characteristics of a mature tropical cyclone with an eye and eye-wall along with a warm core structure. The model-simulated precipitation intensity and distribution were in good agreement with the observations. The ensemble mean of all 12 experiments produced reasonable intensity and the best track.  相似文献   

千百年尺度气候快速变化及其数值模拟研究进展   总被引：1，自引：0，他引：1  

靳立亚  陈发虎 《地球科学进展》2007,22(10):1054-1065

千百年尺度全球气候快速变化是古气候研究中的一个重要内容。研究发现，末次冰期和全新世都存在着千年、百年尺度的快速气候变化，其变化幅度可以达到典型的地质变化或天文因子所造成的冰期/间冰期的气候振荡幅度，同时这些古气候事件具有全球性。对冰期和全新世气候变化的数值模拟揭示了气候系统对地球轨道参数变化的响应以及海洋、植被、冰盖、温室气体等反馈因子的重要性,其中大洋温盐环流对北大西洋淡水注入的敏感性与末次冰期和全新世气候快速变化密切相联。利用中等复杂程度的气候模式（EMIC）CLIMBER 2模拟了末次冰期典型时段（60~20 ka BP）D/O和Heinrich事件以及东亚气候的响应过程。模拟研究揭示了全新世青藏高原冰雪环境对亚洲—非洲季风气候的显著影响。今后的古气候模拟研究将在改进模式分辨率、结合古气候代用资料确定更加符合历史时期边界条件以进一步改善气候模式的基础上,更加注重气候突变机制的研究以及加强全球变化背景下的区域气候的长期变化研究。  相似文献   

关于地震灾害快速评估系统的思考   总被引：5，自引：0，他引：5  

杨天青  姜立新 《地震》2005,25(3):123-128

基于地震快速评估经济损失结果与地震现场调查得到的经济损失结果有较大的差异现象, 为了进一步提高地震快速评估经济损失结果的精确性, 笔者通过对地震快速评估经济损失结果和实际现场调查得到的经济损失结果进行对比研究, 并从建筑物单价和建筑物损失比的角度对快速评估结果进行修正, 以发生在云南境内的10次典型地震为例, 初步得出了对地震经济损失快速评估结果粗略的修正系数。 在一定程度上较大提高了地震快速评估经济损失的精确性。 为地震救援指挥工作提供了更加可靠的依据。  相似文献