有限单元数值模拟在张家界风景区地质调查中的应用

对张家界风景区进行1/25000遥感地质调查,解译出1031条线性构造,经野外验证可靠性达85％,新确认该区存在北北东向褶皱,提出了该区经历了两次以上的褶皱构造运动的新认识。认为北北东和北东东向构造是该区的基本构造骨架,设计了区域性印支期和张家界风景区印支期、燕山早期、燕山晚期四种应力场模型,采用有限单元法进行构造应力场反演计算,所获结果与野外调查结果吻合。认为砂岩峰林地貌是泥盆纪石英砂岩处于宽缓向斜扬起端及后期背斜叠加使地层趋于水平的部位才利于砂岩峰柱的稳定形成,多次构造应力作用产生的高角度裂隙有利于峰林地貌的造型,挽近时期地壳抬升是峰林地貌形成的动力。     

Geomorphic evolution of the Southern Alps,New Zealand

The Southern Alps are the topographic expression of late Cenozoic (<8 Ma ago) uplift of the crust of the leading edge of the Pacific plate in South Island, New Zealand. New fission track data on the basement exposed in the Southern Alps quantify the age, amount, and rate of rock uplift, and in combination with geomorphic parameters permit the construction of a new model of the geomorphic evolution of the Southern Alps. The model emphasizes the development over time and space of rock uplift, mean surface elevation, exhumation of crustal section, and relief. The earliest indications of mean surface uplift are between 4 and 5 Ma ago at the Alpine Fault. Mean surface uplift, which lagged the start of rock uplift, propagated southeastward from the Alpine Fault at a rate of 30 km/Ma. By about 4 Ma ago, exhumation had exposed greywacke basement adjacent to and east of the entire 300 km long central section of the Alpine Fault. At 3 Ma ago, greenschist was exposed in the southern parts of the Southern Alps near Lake Wanaka, and since then has become exhumed along a narrow strip east of the Alpine Fault. The model infers that amphibolite grade schist has been exhumed adjacent to the Alpine Fault only in the last 0·3 Ma. The age of the start of rock uplift and the amount and rate of rock uplift, all of which vary spatially, are considered to be the dominant influences on the development of the landscape in the Southern Alps. The Southern Alps have been studied in terms of domains of different rock uplift rate. At present the rate of rock uplift varies from up to 8–10 mm/a adjacent to the Alpine Fault to 0·8–1·0 mm/a along the southeastern margin of the Southern Alps. This spectrum can be divided into two domains, one northwest of the Main Divide where the present rock uplift rates are very high (up to 8–10 mm/a) and exceed the long-term value of 0·8–1·0 mm/a, and another to the southeast of the Main Divide where the long-term rate is 0·8–1·0 mm/a. A domain of no uplift lies immediately to the east of the Southern Alps, and is separated from them by a 1·0–1·5 km step in the basement topography. We argue that this spatial sequence of uplift rate domains represents a temporal one. The existing models of the geomorphic development of the Southern Alps—the dynamic cuesta model of J. Adams and the numerical model of P. Koons—are compared with the new data and evolutionary model. Particular constraints unrealized by these two earlier models include the following: the earlier timing of the start of rock uplift of the Southern Alps (8 Ma ago); the spatial variation in the timing of the start of rock uplift (8 Ma ago to 3 Ma ago); the lower long-term rock uplift rate (0·8–1·0 mm/a) of the Southern Alps for most of the late Cenozoic; the lag between the start of rock uplift and the start of mean surface uplift; and the patterns of the amounts of late Cenozoic rock uplift and erosion across the Southern Alps.     

东天山戈壁荒漠景观区地球化学勘查中某些工作方法的研究

通过东天山地区地球化学勘查中某些方法的试验,研究了一套适宜于戈壁荒漠景观中地球化学勘查的工作方法.（1）查明了盛行风对岩屑异常特征的影响程度;（2）推荐消除风成沙影响的合理采样粒级;（3）利用水溶态铜、金异常指示被运积物掩盖的铜、金矿体;（4）明确了荒漠区盐磐层不会阻碍在残积物覆盖区发现矿致岩屑异常和在运积物覆盖区发现后生晕.     

不同地球化学景观区的化探方法及实例

总结了最近20多年来化探在找矿过程中起到的重要作用,重点介绍了不同地球化学景观条件下最佳化探找矿方法及实例,为以后的找矿工作提供切实可行的方法,从而达到快速、经济、效果显著的目的.     

Spatio-temporal differentiation of landscape ecological niche in western ecological frangible region: A case study of Yan’an region in northwestern China

In this study, we attempt to put forward a conception of landscape ecological niche, enlightened by international scholars on extending the ecological niche theory from spatial niche to functional niche. That is helpful for comprehensively appraising landscape spatial patterns and ecological functions, also, presents a new method for analyzing landscape fea-tures from multidimensional aspects. The practice process is demonstrated by taking Yan’an region in northwestern China as a case. Firstly, the indices system including spatial attribute and functional attribute is established for assessing landscape ecological niche. Additionally, two-dimensional figures are drawn for comparing the spatio-temporal features of landscape ecological niche in 1987 and 2000 among the 13 administrative counties. The results show that from 1987 to 2000, towards Yan’an region, spatial attribute value of landscape ecological niche changes from 1.000 to 1.178 with an obvious increment, and functional attribute value changes from 0.989 to 1.069 with a little increment, both of which enhance the regional landscape ecological niche. Towards each county, spatial attribute value of landscape eco-logical niche increases to different extent while functional attribute value changes dissimilarly with an increment or a decrement.     

Spatio-temporal differentiation of landscape ecological niche in western ecological frangible region： A case study of Yan＇an region in northwestern China

In this study, we attempt to put forward a conception of landscape ecological niche, enlightened by international scholars on extending the ecological niche theory from spatial niche to functional niche. That is helpful for comprehensively appraising landscape spatial patterns and ecological functions, also, presents a new method for analyzing landscape features from multidimensional aspects. The practice process is demonstrated by taking Yan＇an region in northwestern China as a case. Firstly, the indices system including spatial attribute and functional attribute is established for assessing landscape ecological niche. Additionally, two-dimensional figures are drawn for comparing the spatio-temporal features of landscape ecological niche in 1987 and 2000 among the 13 administrative counties. The results show that from 1987 to 2000, towards Yan＇an region, spatial attribute value of landscape ecological niche changes from 1.000 to 1.178 with an obvious increment, and functional attribute value changes from 0.989 to 1.069 with a little increment, both of which enhance the regional landscape ecological niche. Towards each county, spatial attribute value of landscape ecological niche increases to different extent while functional attribute value changes dissimilarly with an increment or a decrement.     

Rockfall hazard in the Daisekkei Valley, the northern Japanese Alps, on 11 August 2005

This paper describes a rockfall event in the Daisekkei Valley of Mount Shirouma-dake (2,932 m), the northern Japanese Alps. The rockfall occurred on a steep cliff comprising well-jointed felsites and produced debris of ≥8,000 m³. Most debris was deposited on an elongated snowpatch located immediately beneath the cliff, and it caused casualties among people who were trekking along a trail on the snowpatch. Additionally, a large rock block slipped 1 km on the snowpatch. The rockfall could have been due to the differential retreat of the rockwall, which contains areas of high- and low-density joints. Seasonal and diurnal freeze–thaw activities and snow avalanches and wash appear to be important factors responsible for the retreat. Although some rock blocks that can collapse further remain on the rockwall, the position of the mountain trail in the Daisekkei Valley is fixed. Fundamental reform of tourism systems for climbers, including education on natural hazards, is required.     

高山树线交错带的景观格局与生态过程

由于对气候变化的敏感性, 近年来高山树线交错带成为全球变化研究中的热点问题。高 山树线交错带所指示的是一个复杂生态系统的特征, 反映出了由低处植被向高山植被的转化, 其 景观格局是综合了种子定居, 树木生长以及树木繁殖等多个树木生态过程和特定高山环境下的 地理特征格局的适应结果。一方面, 树木通过自身生理生态学上的调整对高山极端环境进行适 应。一方面, 高山特定地理环境特征对树线的景观格局进行影响, 因而高山树线交错带成为研究 景观格局- 生态过程相互关系的一个重要载体。通过运用3S 技术, 可以将高山树线交错带研究中 的树线景观结构和生理生态过程结合在一起, 并验证在其景观格局形成过程中地理特征和人为 因子的相对重要性。     

论文化景观的特性

文化景观是人类活动的产物，文化景观研究是文化地理学的主要研究领域之一，而作为文化景观研究的重要组成部分的文化景观特性研究无疑将推动这一领域研究的进一步发展。运用比较分析方法，根据文化景观的定义，探讨文化景观具有时代性、继承性、叠加性、区域性、民族性等五大特性，并对这些特性进行科学的界定和详细的阐述，展示出这五大特性之间所存在的矛盾统一关系和其内在的紧密联系，进一步说明这些特性的实际意义和利用价值。     

典型岩溶流域不同地貌类型景观结构分析——以云南小江流域为例

利用2003年小江流域的TM影像，结合实地调查，再根据流域地质分布和地貌发育情况，将流域地貌类型划分为岩溶地貌和非岩溶地貌两个一级类型景观，在此基础上，根据地貌发育程度结合高程情况，将岩溶区又划分为6个岩溶景观，非岩溶地貌分为两个二级类型景观。应用景观生态学原理，并通过Fragstats 3．3软件在流域尺度上计算了一些相关指标。结果表明：岩溶区的景观生态特征总体上体现了其生态环境的特殊性和脆弱性，地表水资源溃乏，土层薄、土壤资源零星分布且易流失，造成未利用地面积大，石漠化现象严重，土地利用程度低的特点。非岩溶区景观生态由于耕地和林地占绝对优势，石漠化面积少，香农多样性指数和均匀度低，景观的异质性较低，结构较为简单。