基于高密度电法的滑坡路段地基勘察与稳定性评价

准确地确定滑体的空间形态和稳定状态是制定滑坡治理方案的基础。在北黑高速扩建工程滑坡体勘察中,利用GPS卫星定位系统对山体滑坡路段的地形图进行了测绘,初步确定的滑坡体的周界。以主滑动面为中心线,布设了四条高密度电阻率法测线,并在特征点位置进行了地质钻探。利用高密度电阻率法测量反演结果结合地质钻探资料判断,该滑坡属于堆填土滑坡,一期工程的弃土带动其下坡积的粉质粘土沿基岩顶面产生滑动。利用GPS全球定位系统结合钻孔测斜管对滑坡进行了监测,准确地确定了滑动面位置,判断了滑体稳定状态,测得了滑体的移动方向及移动速率。     

利用“物探+钻探”的探测方法探测石门揭煤区域煤层赋存状态及异常区

在工程地质勘查中物探方法和钻探方法各有所长各有所短,将钻探手段和物探方法有机地结合起来往往能取得既快又准的勘查效果。文章分析某公司井下主运输石门及辅助运输石门进行第二次揭煤作业的情况,同时为掌握清楚石门揭煤区域的煤层赋存状态及异常区,采用瑞利波探测和千米钻机探测的"物探+钻探"的探测方法对石门揭煤区域进行全方位探测。"物探+钻探"技术的应用,能够提高在揭煤前对掘进区域地质构造异常区和水文地质情况的掌握程度,以确保实现石门安全揭煤。     

鹤大公路采空区综合勘察及稳定性评价

利用调查、地质调绘、工程物探及钻探等勘探方法,对鹤大公路K225＋179中桥下部采空区进行综合勘察,查明场地地质构造、地层岩性、采空区分布范围、规模及塌陷情况,采空煤层为15#煤层,上部覆岩为软弱覆岩,塌陷导致地表出现沉降,并引发桥体下沉。进行采空区区域划分及稳定性分析评价,并预测后期位移量,采空区为倾斜煤层采空区,煤层厚度较大,预测后期桥体会发生较大沉陷,并产生较大水平位移。为保证桥梁的安全,根据治理难度分析,提出桥梁移位至无采空区的安全地段,原桥梁拆除后修筑路基的整治方案。     

山地旅游城市滑坡灾害风险性评价——以重庆市为例

滑坡作为主要的地质灾害类型对地区的经济与旅游造成重大影响。以西南山城重庆市为研究对象,选取滑坡诱发因素及影响过程的10个指标,运用ArcGIS空间分析技术,构建由地理环境、地质构造及人类活动因素组成的滑坡灾害危险性评价体系,对重庆市各个县滑坡灾害危险性等级进行评价,结果表明:滑坡危险性评价地理环境因素危险性等级整体较高,达3.13,地质构造因素危险性等级评价全市空间分异较大,平均达2.7,人类活动滑坡危险性评价全市整体等级较高,西部区域尤为明显;滑坡灾害风险等级较高区域面积较大,以3级占比最多,东部地区滑坡灾害危险性大于西部,北部大于南部,高风险等级区域集中分布在三峡库区、长江干流及大巴山脉;各县区滑坡灾害危险性等级排名前3的分别是三峡库区的石柱土家族自治县与万州区,以及西北部主城区北碚区,位于西北角的潼南县滑坡灾害危险性全市最小。本文为山地旅游城市地质安全管理提供理论基础。     

南平市樟湖镇甘蛟垅滑坡勘察与治理建议

南平市樟湖镇甘蛟垅滑坡,滑体纵向长50m、横向宽90m、面积约0.36hm~2,坡下16户移民的生命财产受到威胁,列为省库区办确定专项治理的重点项目之一。文章针对滑坡的工程地质条件和水文地质条件,了解和分析滑坡的产生及发展,提出合理的治理建议。     

集丹公路K6+606-K6+705段滑坡稳定性分析及其加固处理

以具体滑坡工程为例,详细分析了该滑坡的工程地质条件,对其滑动机制进行了阐述。依据滑坡的整体现状,进行分区评价,得出不同区域的稳定性。同时运用刚体极限平衡方法对滑坡进行了整体稳定性和局部稳定性分析计算,确定了支护设计参数,而后在此基础上采用了锚喷、素喷护面、锚索等工程措施进行了综合处理,取得了较好的效果。     

基于GIS与RS三维虚拟林相图可视化技术研究

三维可视化能够使抽象概念且难以直接感知的空间现象现实化以及直观化,利用此技术可以对林地植被进行模拟,虚拟演示林地分布情况,能够获得各种超越现实的空间感知的经验。本研究以湖南省长沙县乌川湖村作为实验区,以1∶10 000的地形图、分辨率为0.5 m的航片以及2013年二类森林资源调查数据等为数据源,充分利用各种数据的优势,把各种数据融为一体,突破了传统的二维林相图,探索出了基于GIS平台的三维林相图的制作,通过三维林相图的制作,不仅能够体验三维森林景观空间变化,立体的、多角度的了解森林组成,直观了解森林空间结构及分布规律,还能够进行查询以及定位功能,方便了林业部门的生产经营和管理。     

三峡库区双龙镇马家屋场—后坪滑坡形成机制与整治

指出了双龙镇马家屋场—后坪滑坡是三峡库区52处重点滑坡治理之一,目前现有地质环境下滑坡处于基本稳定状态。由于三峡水库的修建、蓄水,改变了坡体原有的工程地质条件,地下水位壅高等因素的影响将引起滑坡整体滑动。为了双龙镇新镇建设的顺利推进及保障水库蓄水后新镇库岸的稳定,必须对该滑坡加以治理。为此,提出了整治措施:以抗滑桩为主,辅以锚索加固。     

中国黄土滑坡灾害概述

中国的黄土面积约占国土总面积的6.63%,是世界上黄土分布最广的国家。由于自然条件的限制,滑坡灾害频繁发生,已成为黄土地区社会经济发展的主要障碍。本文通过不同分类指标,把黄土地区滑坡概化为9种类型,并重点分析黄土地区滑坡灾害的时空分布特点以及黄土地区滑坡的影响因子即滑坡机理。指出黄土地区的滑坡在空间分布上与地质构造、地形地貌、地震发育情况、降水密切相关;从地形地貌、地层岩性、新构造运动和地震活动情况、水的影响以及人类活动不同方面对黄土地区滑坡的发生机理进行了分析,发现黄土地区存在易发生滑坡的先天自然条件,而人类活动又加速了滑坡的发生。本文指出控制黄土地区滑坡灾害,寻找最佳防治对策是当前的紧迫任务。表1参14。     

基于ArcGIS的百果园林区地形图数字化与DEM的构建

基于地形图,论述了矢量化的操作步骤,并介绍了利用ArcGIS9.3软件来构建DEM的方法,结合百果园1∶1万地形图和遥感影像图实现地形三维可视化。研究结果表明:使用ArcGIS9.3软件进行地形图数字化的效果好,操作简单,并可快速实现基于遥感图像的地形图三维可视化。     

Using landscape metrics and topographic analysis to examine forest management in a mixed forest,Hokkaido, Japan: Guidelines for management interventions and evaluation of cover changes

In this study, we identified the distribution characteristics of a mixed forest of coniferous and broad-leaved trees (a typical forest type in Hokkaido, Japan) using landscape metrics and topographic factors, and attempted to apply this knowledge to examine forest management. This approach provides a new perspective (i.e., the landscape structure) on forest management, which traditionally has been determined on the basis of individual forest stands. We first created a cover type map of the study area by means of aerial photo interpretation. The characteristics of each cover type identified from the photographs were determined using landscape metrics for each cover class. We digitized a forest administrative map (1:20,000 scale) using 20-m contours, and imported this into GIS software to produce a terrain model; on this model, we overlaid the cover types. Our examination of landscape metrics showed that most of the natural forest could be managed similarly. However, our examination of topographic characteristics revealed exceptions (e.g., areas that are difficult to regenerate) that will require particular attention when managing the natural forest. Based on the information we obtained, we proposed a guideline for sustainable forest management. From the land cover map, we proposed an “improved” cover type map to illustrate the development of a high growing stock of forest based on forest management. We compared the current cover map with the “improved” cover map and demonstrated that the improved form would have more significant effects on fauna that do not recognize differences in the proportion of the dominant species types than on those that can recognize these differences. Our results show how the information obtained using landscape metrics and terrain models is an essential tool for various stages of forest management planning.     

GIS支持下的大富庵风景区景观格局分析

利用1:50000土地利用现状图和1:10000地形图,在Arc GIS和景观结构分析软件Fragstats支持下,运用生态学与景观生态学的基本原理,选取景观斑块数、均匀度、分维数、优势度、破碎度等反映景观空间格局的指数,对大富庵景观格局进行分析。结果表明,林地是景观的基质;裸岩石砾地、居民点与工矿用地、农田的分维数低,破碎度高,受人类活动干扰程度较大;林地分维数高、破碎度低,植被保护较好;研究区多样性较低、均匀度低、优势度高,说明了景观类型并不丰富,异质性不高。     

Regional estimation of Japanese cedar (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis> D. Don) productivity by use of digital terrain analysis

Digital terrain modeling and spatial climatic data have been used to estimate the spatial distribution of Japanese cedar (Cryptomeria japonica D. Don) forest productivity on a regional-scale. The study was conducted on Japanese cedar forests in Himi city, Oyabe city, Takaoka city, and Imizu city (a total area of 683 km²) in northwestern Toyama Prefecture. On the basis of data from 146 sample stands, above-ground net primary productivity (ANPP) was calculated from tree height, age, and density using existing ANPP conversion equations for Japanese cedar stands. Six topographic factors (slope, profile curvature, plan curvature, openness, wetness index, and topographic radiation index) were calculated from a 10-m cell size digital elevation model. Three climatic factors (annual mean temperature, annual total precipitation, and annual maximum snow depth) were obtained from an existing spatial data set. Relationships between ANPP and environmental factors were analyzed by regression tree models. For the tree model with ANPP as a dependent variable, four environmental factors (annual mean temperature, wetness index, openness, topographic radiation index) were adopted as independent variables. Annual mean temperature was the first split variable in this model and explained 25.5% of the total deviance in ANPP. Wetness index, which represents soil moisture variation caused by lateral flow, explained 11.5% of the total deviance in ANPP. The resulting tree model explained approximately half of the total deviation in ANPP and indicated that the spatial distribution of Japanese cedar productivity was controlled by regional-scale interactions between climatic and topographic processes. A high-resolution map of productivity was prepared by use of the ANPP prediction model and vegetation information obtained from satellite data.     

Distribution of Landscape Elements Along Environmental Gradients in Over-Cut Forests

The method of trend surface analysis was used to analyze the distribution of landscape elements along environmental gradients in Jingouling forest farm, northeast China’s Jilin Province. Results showed that topographic characteristics and disturbance pattern have much more impacts on the distribution of landscape elements than do horizontal geographical position in the study area. The elevation, slope aspect, and slope degree were found to be dominant features controlling landscape pattern. At different altitudinal ranges, the effects of slope aspect and slope degree on the distribution of landscape elements vary markedly in orientation and intensity. These differences were analyzed and discussed, and some basic rules of spatial distribution of landscape elements were proposed. Translated from Scientia Silvae Sinicae, 2004, 41(1) (in Chinese)     

基于DEM的森林景观与自然度空间分异研究

该研究在Arc GIS支持下,建立乐东县数字高程模型(DEM)模型,提取海拔、坡度、坡位、坡向等各地形因子,将森林分为10种景观类型,并结合自然度与地形进行叠加分析,分析结果表明,森林资源景观分异频度与地形关系显著,各景观格局分异特征的形成,是自然选择的结果,也有人工干扰的因素。     

数字地形图在青海玉树至西藏昌都公路设计方案中的具体应用

本世纪初前10年,是我国公路建设的高峰期,众多项目纷纷上马,这就要求尽可能提高生产效率,缩短生产周期。在这个大背景下,很多最新的、先进的科研成果都引入和应用到公路设计领域,而数字地形图的广泛应用就是这一趋势的体现。本文通过工程实例,介绍了数字地形图在公路设计方案中的具体应用。     

基于ArcGIS 10的公益林建设作业设计图制作方法及步骤

基于ArcGIS 10应用软件,以制作公益林建设项目作业设计图为例,阐述林业工程项目作业设计图的一般制作方法和步骤,包括栅格地形图坐标定义和地理配准,建立点、线、面数据层,以及项目位置示意图和小班作业设计附图的制作方法及步骤.