新疆北山库姆塔格沙垄沙丘的形态特征分析

为进一步探讨新疆维吾尔自治区北山库姆塔格地区沙漠成因和保护生态环境提供依据,分析了该区沙垄的形态特征.对库姆塔格沙垄地区的ETM遥感图像裁剪出相对应的沙丘形态类型图像,并进行锐化增强处理;基于SRTM数据,通过ArcGIS软件的三维分析模块得出库姆塔格沙垄的高程图;根据当地的地形地貌特点绘制简易的主风向图;详细分析每种类型沙丘的特征.研究表明:库姆塔格沙垄由于其独特的自然地理特点,形成狭长的“S”型沙垄,沙丘形态复杂多样;该区沙丘类型主要以新月形沙丘链和复合型纵向沙垄为主,单个新月形沙丘较零散,线性沙丘分布较少,树枝状沙丘还处于雏形.     

艺术的线性沙丘

在埃及西南部撒哈拉沙漠的深处,是风主宰着这里地貌的轮廓.从几千年前开始,北方吹来的风就不停地将沙地塑造成大型沙丘,而沙丘则应着风的方向柔顺地平行排列着.     

基于ArcGIS、MATLAB及Surfer的DGPS冰碛垄测量模拟对比

应用ArcGIS软件中的Topo to Raster工具、MATLAB软件中的人工神经网络及Surfer软件中自然邻点法,本文对使用差分GPS测量的青藏高原不同地区的冰碛垄数据进行了数字地貌模拟,从模拟精度、准确度、地貌晕渲、易操作性及后期定量分析等方面进行了分析对比。结果表明ArcGIS中的Topo to Raster工具较其他两种方法有较好的模拟精度;综合考虑各方面因素,ArcGIS软件在冰碛垄地貌的定量研究中具有优势。     

基于ArcGIS、MATLAB及Surfer的DGPS冰碛垄测量模拟对比

应用ArcGIS软件中的Topo to Raster工具、MATLAB软件中的人工神经网络及Surfer软件中自然邻点法,本文对使用差分GPS测量的青藏高原不同地区的冰碛垄数据进行了数字地貌模拟,从模拟精度、准确度、地貌晕渲、易操作性及后期定量分析等方面进行了分析对比。结果表明ArcGIS中的Topo to Raster工具较其他两种方法有较好的模拟精度;综合考虑各方面因素,ArcGIS软件在冰碛垄地貌的定量研究中具有优势。     

黑河正义峡水利枢纽工程应用GPS测量技术的精度评估

在黑河正义峡水利枢纽及内蒙古输水干渠规划设计阶段测量中,地黑河河道及附属建筑物、料场等带状地形图的测量建立了ＧＰＳ控制网。本文对布网方案,实施过程及数据处理后成果精度作了分析。实践证明ＧＰＳ测量技术对全天候,精度高,速度快等特点,特别是对黑河地区那样的气候恶劣、昼夜温差大,风沙大;风蚀风化很严重的地质地貌条件,从山区峡地沙漠戈壁地区这样复杂的自然环境下,比常规测量快速,准确的提高了成果精度。不失为     

基于三维激光扫描的地质立体模型的建立

针对复杂地貌和地质构造条件下数值模拟的具体问题,根据从局部到整体的模型划分思想,综合运用FLAC~(3D)、SURFER等平台,采用Wedge与Brick块体单元,通过编程实现三维地质地貌。利用趋势面多项式拟合方法生成层状连续的不同岩性地质体,采用interface界面来处理小范围断层上、下盘的断层面,而在上、下地壳分层建模中,使用添加attach face的方法来处理两层物质间的分界面,解决了FLAC~(3D)在建立断层、三维地质模型中常见的一些关键技术问题。     

敦煌雅丹 国家地质公园

位于甘肃我国著名历史文化名城敦煌市西北约180公里处,玉门关西北约100公里处,面积398平方公里,主要地质遗迹为风蚀作用形成的雅丹地貌。地质公园内集中连片地分布着各种各样造型奇特的风蚀地貌,例如,"蒙古包"、"骆驼"、"石鸟"、"石人"、"石佛"、"石马"等。它宛如一座中世纪的古城,世界许多著名的建筑都可以在这里找到它的缩影,令世人瞠目。夜幕降临之后,尖厉的     

巴丹吉林沙漠北缘风沙地貌图的地图设计

风沙地貌图所表示的基本内容,是以风沙地貌的成因、形态及实体类型为基础,反映部分地貌年龄和地面组成物质,以图像化的形式表示各种地貌实体的自然形状及其组合结构关系,为分析风沙地貌发育过程、沙丘移动方向,以及内外营力对沙漠形成的作用提供可靠的依据。地貌图的编制采用室内研究、编辑为主的制图方法,尽量吸收相关学科的有关资料,进行必要的野外调查,并且重视长期以来传统的区域地貌调查方法,注重有关地面验证及典型区域特征。一、编制目的与技术路线本风沙地貌图的编绘目的旨在直观展示巴丹吉林沙漠风沙地貌的形成演化过程及…     

编制1∶500000福建省地貌图中几个制图问题的分析和探讨

引言“福建省地貌区划”工作是福建省自然区划的一个组成部分,是农业自然条件、自然资源和农业区划中的研究课题,1:500000“福建省地貌图”的编制又是各类区划工作的主要内容。1980年开始对“福建省地貌图”的编制进行一些试验工作;1983年开始编绘地貌图的作者原图,经野外调绘,于1986年6月完成作者原图的编绘,本文就编制1:     

遥感在某些地区成矿构造条件研究中应用的若干体会

近几年来在长江中下游、胶东及一些火山岩地区,利用遥感资料对某些内生金属矿产成矿地质条件、找矿标志研究曾进行过大量工作,并取得了显著效果,笔者根据这些研究成果曾编写过一份讲义,在去年夏天烟台金矿遥感解译班上作过介绍。应学员要求,笔者对这个讲义重新进行了整理,并补充了一些内容,撰成本文。在叙述正文前,我们将遥感用于矿产地质研究的情况简略回顾一下。     

Remote sensing applications in the study of landuse and soils of aeolian cover op the western part of Haryana State

Multispectral and multitemporal landsat-FCC of 1:250,000 and transparancies on 1:1000,000 scales of bands 4, 5, 6 and 7 were interepreted to identify and delineate the areas under varying intensities of dunal activity in the western part of Haryana State comprising an area of 12610 sq. km. CCTs of some representative areas were also interpreted on the Multispectral Interactive Data Analysis System. Field checks were made to correlate the laboratory interpretation and the ground truth. The study areas were differentiated into the following units: (1) Sandy desert zone: No cultivation on dune tops except some shrubs, (2) Aeolian cover with sandy hummocks: low intensity cultivation, (3) Plain with aeolian cover: moderately cultivated, (4) Plain: Moderately to intensively cultivated. The major soils in association were Typic Torripsamments/Ustipsamments/Ustorthents/Ustifluvents/Calciorthids and Natric Camborthids.     

A geological cum geomorphological framework of haryana and adjoining areas for landuse appraisal using landsat imagery

The state of Haryana and the adjoining areas are covered to a large extent by Quaternary sediments of alluvial/aeolian origin. An attempt has been made to study this area and classify the various geomorphic zones and a geological-cum geomorphological map of the area has been prepared based on MSS Landsat Imagery on 1:1 million. The geological set-up of the area comprises the sub-Himalayan system of rocks, mostly belonging to Siwalik Group which are exposed in the northeastern extremity and adjoining parts. In the south and southwestern corner of Haryana bordering the state of Rajastan, older rocks belonging to Delhi Supergroup are exposed. In between lies the vast stretch of Quaternary sediments of aliuvial/aeolian origin. The different geomorphic units recognised include 1) High structural hills, 2) Moderate structural cum denudational hills, 3) Low structural-cum-denudational hills, 4) Older and younger piedmont zones, 5) Flood plain, 6) Older Alluvial surface, 7)Aeolian zone, 8) Transitional zone & 9) Upland tract. Except the river Yamuna flowing along the eastern boundary of the State, the only other stream is the Ghagghar. A well-defined palaeo-channel of the Ghagghar is clearly picked up on the imagery. This river appears to be structure controlled and flows along well-defined tectonic lines. The southerly to southeasterly direction of flow of the river Yamuna indicates a basement high. The topographical low passing through Delhi-Rohtak-Hissar and Sirsa appears to coincide with basement high and the gradual shift in the drainage system indicates some neotectonic activity in the region. The most important ecological problem of the state of Harayana is the rapid desertification due to migration of dunal sands in the south and southwestern parts. Other environmental problems related to landuse are the salt efflorescence, waterlogging, unscientific stone quarrying, etc. It is felt that geomorphic maps generated should be utilised for regional land-use planning and restoration of the eco-balance in the State.     

Forms of aeolian sandy deposits in parts of rajasthan based on aerial photo-interpretation

Aerial photographs are invaluable for study of terrain characteristics which are reflected in the morphology-form and association of different physiographic units in any area. Based on environmental controls of geology, relief, dominant geomorphic process and climate, a system of landscape classification has been evolved. Characteristic physiographic units in any area are identified and defined based on their form, slope variations, orientation, spacing, surficial deposits and water regime. Only two units i.e. landscape pattern and facet are adopted in the classification system. The dominant aeolian process evolves a variety of forms and associations. The most important forms evolved are long sandy ridges with variation in spacing and directions, shifting sand dunes-both scattered and in clusters and various combinations of short sandy ridges. The paper describes the form, assocation and characteristics of one of the landscape patterns classified in the desert area. The norms established on the basis of aerial photo-interpretation thus help to infer terrain characteristics at different places where the pattern occurs.     

Dune dynamics and evolution of aeolian landforms in parts of Jaisalmer district,Rajasthan, India

Three major dune-forming episodes are inferred in western parts of Rajasthan Desert. Massive and large-sized oldest dunes show crescentic, stabilised megabarchanoids or transverse, draas formed by stronger intensity southerly to southeasterly winds. These draas were transformed into linear and parabolic dunes through aeolian scouring and superimposed accretion of second and subsequent generations. The youngest aeolian reactivation here is represented by selective deflation and depositional linear arrays of active small barchans, vegetation-induced aeolian accumulations and prograding sand sheet Dune trends of younger-evolved forms suggest establishment of the southwesterly sand-moving wind circulation patterns during second-generation aeolian episode and its persistence of directional flows though with significantly lesser intensity into the contemporary wind regime in the area.     

Demarcation of palaeochannels and integrated ground water resources mapping in parts of Hisar district,Haryana

Present study deals with the demarcation of palaeochannels and mapping of integrated water resources in parts of Hisar district, Haryana using Indian Remote Sensing Satellite (IRS-1D) LISS-III Data of December 21, 2001. The landforms identified are Sand Dune, Dune Complex, Aeolian Plain, Fluvioaeolian plain, Palaeochannel and Younger Alluvial Plain formed by aeolian, fluvio-aeolian, and fluvial processes. These palaeochannels are first time demarcated in the area. The ground water prospects of various geomorphic units have been assessed. Depth to water level and ground water quality maps were digitized and put in to GIS format. Ground water prospects and quality maps were integrated and depth to water level information was draped on it to prepare final integrated ground water resources map. This map depicts ground water prospects, quality and depth together in a single map, which will help in and ground water exploration.     

Soilscapes,geomorphic processes and soil taxonomic new subgroups identified in the Ghaggar river basin of Haryana and Punjab

Soilscapes of the Ghaggar river basin falling in Haryana and Punjab were interpreted and studied by using the Landsat imagery and aerial photographs. Five major landform units identified and demarcated in the area were : channel courses, levees, flood-plains undulating, basinal floodplains and relict basins. On the basis of sedimentation, nature of the river pattern and soil characteristics, the whole basin was divided into three reaches — upper, middle and lower. Taxonomically the soils were placed under Typic Ustipsamments, Typic Ustorthents and lypic Ustifluvents on channel courses; Aquic Ustifluvents, Typic Ustifluvents and Typic Ustochrepts on levees; Fluventic Ustochrepts, Udic Ustochrepts and lypic Camborthids on floodplains undulating; Typic Ustorthents and Udic Ustochrepts on basinal floodplains; Typic Natrustalfs and Natric Camborthids on relict basins. Two new subgroups were proposed, i.e., Natric within the order of Entisol and Inceptisol, and Aquic-udic within the order of Inceptisol. Two dominant geomorphic processes were observed, i.e., fluvial and aeolian.     

Confirmation of soil physiographic units through soil mineralogy studies in Yamuna alluvial plain,India

A confirmatory study of soil physiographic units identified through aerial photo interpretation technique, in Yamuna alluvial plain, Haryana is presented here. The area under study is part of Yamuna alluvial plain in Sonepat district, Haryana. Shanwal and Malik (1980) studied and mapped this area (semi-detailed) on 1:25,000 scale through areial photo interpretation technique. The soil profile samples of major soil physiographic units of the area were fractionated into sand, silt and clay. Detail mineralagical studies were carried out through electron microscopic and X-ray diffractometer studies in order to know their nature and origin of the parent material. X-ray diffraction data shows that mineralogy of different fractions (Sand, silt and clay) of soils samples, of different physiographic units were similar except Lavee. In this area mica is the dominant day mineral in the soils followed by Kaolinite, chlorite, vermiculite and smectite in decreasing order of their abundances. The occurance of fibrous minerals in coarse clay and silt fraction of soil samples of Lavee physiographic unit is the interesting feature of this area. The presence of fibrous minerals indicates that this overlain material designated as natural Levee in this area is not the alluvium brought down by the river Yamuna but is aeolian material flown from adjoining deseret of Rajasthan and deposited as stabilized sand dune. The fibrous minerals have been reported earlier in the desert of Rajasthan.     

Identification of palaeochannels around Cauvery river near Talakad, Karnataka using remote sensing data

Visual interpretation of satellite images could help in the identification of present and past landforms. An attempt has been made to identify the palaeochannels of the Cauvery river in Karnataka state through visual interpretation of IRS-1C, LISS III False Colour Composites (FCC). In order to assess their inter-relationship with other hydrogeomorphic elements, various geomorphic units have been mapped. Major geomorphic units like alluvial plain, pediplain, valley fill. residual hill, ridges, meander scar, channel bars and water bodies have been demarcated. Considering the hydrogeomorphic setup of the palaeochannels. it is inferred that the disposition of palaeochannels of the area are controlled by the geology and structure and the prevailing geomorphic process.     

GIS-based geomorphological mapping using remote sensing data and supplementary geoinformation: A case study of the Dhaka city area,Bangladesh

This study aims to prepare a detailed GIS-based geomorphological map accompanied with landfill sites of Dhaka city area which can be used for multipurpose functionality. Attainment of the geomorphological map is based upon interpretation of the oldest available aerial photographs (1:40,000) and contemporary topographic maps (1:8000) which reflect almost pre-urban ground of Dhaka. Randomly distributed 160 boreholes have been used to prepare representative soil profiles (RSP) to identify the near-surface lithology of the geomorphological units. The study reveals that 13 out of 18 low-lying geomorphic units, comprising 65% of the total area demand landfill practices for urban development. Landfill sites have been merged with urban growth on each low-lying geomorphic unit using a spatially enhanced fused image of IRS-1D PAN and ETM+ bands 5, 4 and 3, acquired February 2000 and 2002, respectively. We found that 43% area of the total low-lying geomorphic units experience fill practices so far. The fill sites have been differentiated into four classes based on their relative thickness. Integration of fill classes with geomorphological map shows the urban dynamics of Dhaka city area till 2002. Due to GIS integration, this map can be rapidly updated to demonstrate temporal modifications in urban ground. It can be used effectively in different geomorphological hazard mapping and urban land-use practices.     

Hydrological evaluation of morphological features of some parts of hamirpur,jhansi, banda and fatehpur districts,up-using air photo-interpretation technique.

The paper embodies the result of an approach used in hydrogeological evaluation of morphological features of fluvial terrain in some parts of Uttar Pradesh. This study of hydrogeological effects from morphological features is based on landscape-indicatory studies only. Aerial photographs of 1:60,000 scale have been used in mapping geomorphic units. Hydrologie characterstics of these have been discussed. Abandoned river channels in the flood-plain are expected to yield appreciable quantities of groundwater.