Modeling of rainfall-triggered shallow landslide

By integrating hydrological modeling with the infinite slope stability analysis, a rainfall-triggered shallow landslide model was developed by Iverson (Water Resour Res 36:1897-1910, 2000). In Iverson’s model, the infiltration capacity is assumed to be equivalent to the saturated hydraulic conductivity for finding pressure heads analytically. However, for general infiltration process, the infiltration capacity should vary with time during the period of rain, and the infiltration rate is significantly related to the variable infiltration capacity. To avoid the unrealistically high pressure heads, Iverson employed the beta-line correction by specifying that the simulated pressure heads cannot exceed those given by the beta line. In this study, the suitability of constant infiltration capacity together with the beta-line correction for hydrological modeling and landslide modeling of hillslope subjected to a rainfall is examined. By amending the boundary condition at ground surface of hillslope in Iverson’s model, the modified Iverson’s model with considering general infiltration process is developed to conduct this examination. The results show that the unrealistically high pressure heads from Iverson’s model occur due to the overestimation of infiltration rate induced from the assumption that the infiltration capacity is identical to the saturated hydraulic conductivity. Considering with the general infiltration process, the modified Iverson’s model gives acceptable results. In addition, even though the beta-line correction is applied, the Iverson’s model still produces greater simulated pressure heads and overestimates soil failure potential as compared with the modified Iverson’s model. Therefore, for assessing rainfall-triggered shallow landslide, the use of constant infiltration capacity together with the beta-line correction needs to be replaced by the consideration of general infiltration process.     

我国水资源承载力研究现状及展望

概要说明了我国水资源承载力的研究现状,阐述了水资源承载力的概念、内涵及影响因素,探讨了目前几种常用的水资源承载力评价方法,并对当前研究中存在的问题进行了初步分析,进而提出了我国水资源承载力的研究趋势。     

小岩头滑坡稳定性分析

小岩头滑坡位于贵州省威宁县二(连浩特)河(口)高速公路K255 010~K255 240里程右侧,属一个大型古滑坡,发育于二叠系上统峨嵋山组玄武岩(P2β)地层中。在高速公路施工中对路堑进行深挖削坡,可能导致古滑坡中部、线路右侧斜坡失稳破坏,发生滑坡。因此,滑坡稳定性评价是重大工程地质问题之一。根据大量勘察试验资料,系统地揭示了滑坡的特征,分析了滑坡形成的控制因素、成因和形成机制,建立了滑坡体稳定性计算模型,利用反演计算法进行稳定性分析与评价,认为两滑体均处于滑动失稳状态。建议对滑坡体进行处理,采用排水、支挡、减压等措施进行整治。     

Site Investigation for the Effects of Vegetation on Ground Stability

The procedure for geotechnical site investigation is well established but little attention is currently given to investigating the potential of vegetation to assist with ground stability. This paper describes how routine investigation procedures may be adapted to consider the effects of the vegetation. It is recommended that the major part of the vegetation investigation is carried out, at relatively low cost, during the preliminary (desk) study phase of the investigation when there is maximum flexibility to take account of findings in the proposed design and construction. The techniques available for investigation of the effects of vegetation are reviewed and references provided for further consideration. As for general geotechnical investigation work, it is important that a balance of effort is maintained in the vegetation investigation between (a) site characterisation (defining and identifying the existing and proposed vegetation to suit the site and ground conditions), (b) testing (in-situ and laboratory testing of the vegetation and root systems to provide design parameters) and (c) modelling (to analyse the vegetation effects).     

地震地质灾害空间预警评估定量化方法研究初探

建立“发育度”、“潜势度”、“危险度”、“危害度”等概念来描述地震地质灾害各影响因子、要素及可能的灾害危害程度,进而建立构成地震地质灾害层次分析的概念体系及地震地质灾害空间预警评估模型,将定性评估转化为定量评估进行初步研究。     

二维地震观测系统合理性的论证方法

已知勘查区深度范围前提下,最大炮检X和道间距ΔX,不可以太大也不可以太小,施工前能够计算出它的允许值范围。     

MODIS数据在广西生态环境监测及评价中的应用方法

利用MODIS数据广西遥感影像,用监督分类法做出了地物覆盖分类图,用主成分分析法做出了土壤侵蚀强度图和生态环境质量综合评价指数图。     

区域大气环境质量灰关联评价方法探讨

针对区域中大气环境质量的特点，采用对数主成分分析方法获得各环境指标的权重及各监测点的横向排名，再用适宜的灰度关联方法进行了评价。整个过程在MATLAB6．5中实现，计算简便易行，与传统的综合指数法相比较，其评价结果更符合客观实际。     

基于点重要度的地形LOD简化算法及精度

在分析、讨论目前关于3维地形模型简化与误差控制方法的基础上,提出了一种基于点重要度进行连续LOD模型简化的算法.并以5种典型地貌的实验数据作为运行实例,给出了点重要度与地貌类型之间的精度关系.这为今后连续LOD模型的合理建立提供了一种新思路和方法,也为模型的简化提供了科学依据.     

香港DTM快速建立的研究

本文论述了建立1：5000香港DTM的基本过程，总结了在DTM生产实践中的技术和管理上所取得的一些经验，对生产中各环节的实际问题提出一些建议，对提高所建立DTM的精度与可用性及提高工作效率，具有一定的意义，为以后各种比例尺的DTM生产提供参考。