ArcGIS及SQLServer在地籍管理信息系统中的应用     

陈德鑫 《现代测绘》2010,33(4)

地籍管理是国土资源管理的核心,专业性强,数据量大,任务繁重。传统的管理方法已不能满足需求,而GIS及RDBMS的发展则为建立现代地籍管理系统提供了可能。本文阐述了地籍信息系统的总体构架,着重分析了Arc/Info、SQL Server及Delphi在建立地籍管理信息系统中的应用。  相似文献   

雾迷山旋回层的费希尔图解及其在定义前寒武纪三级海平面变化中的应用   总被引：16，自引：1，他引：16       下载免费PDF全文

梅冥相  马永生  周洪瑞  杜本明  罗志清  郭庆银 《地球学报》2001,22(5):429-436

天津蓟县剖面的中元古界雾迷山组是一套厚 3 3 0 0m的碳酸盐岩地层 ,其中广泛发育叠层石生物层及凝块石生物丘。这些生物层及生物丘与潮坪相白云岩和砂泥质白云岩一起构成具有近似对称相序组构的环潮坪型碳酸盐米级旋回层序 ,将其命名为“雾迷山旋回层”。这些旋回层常由泻湖相白云质泥页岩覆盖 ,在其顶常发育古土壤层 ,由此而表明雾迷山旋回层的界面多为瞬时暴露间断面。根据雾迷山旋回层在长周期三级层序中的有序叠加形式 ,可在雾迷山组中识别出 2 6个Ⅲ级层序 ,它们还可进一步归为 6个Ⅱ级层序。为了进一步研究三级海平面的变化幅度和Ⅲ级层序的大致形成时限 ,在露头发育良好的雾迷山组中上部共识别出 62 6个旋回层 ;考虑到雾迷山组的总体厚度 ( 3 3 0 0m)及其大致的总体形成时限 ( 10 3± 2 0Ma左右 ) ,可假定雾迷山组沉积期的总体地壳沉降速率为 2～ 4m/ 10万a。在上述假定的基础上 ,运用费希尔图解来估算三级海平面的变化幅度。  相似文献   

THE LISEM PROJECT: AN INTRODUCTION     

A. P. J. DE ROO 《水文研究》1996,10(8):1021-1025

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USING SPECTRAL ANALYSIS TO DETECT SENSOR NOISE AND CORRECT TURBULENCE INTENSITY AND SHEAR STRESS ESTIMATES FROM EMCM FLOW RECORDS     

M. F. LAPOINTE  B. DE SERRES  P. BIRON  A. G. ROY 《地球表面变化过程与地形》1996,21(2):195-203

Electromagnetic current meters (EMCMs) are frequently used to gather turbulent velocity records in rivers and estuaries. Experience has shown that, on occasion, the output of these sensors can be affected by contamination from various noise sources. These noises may be limited to narrow bands of frequencies and thus fail to produce conspicuous increases in observed signal variance. Such ‘narrow-band’ noises can be difficult to identify from simple inspection of signal traces or variance levels, yet degrade estimates of turbulence statistics, in particular covariances (used to calculate Reynolds shear stress). This paper demonstrates the usefulness of spectral analysis to detect and characterize narrow-band noise components in turbulent flow records. Statistical principles underlying the use of spectral analysis for noise detection are briefly reviewed. Examples of u and v velocity spectra and cospectra are then presented from actual EMCM velocity records from flume and field deployments that were found to be contaminated by such noises. The sensitivity of the shear stress estimates to even minor noise levels is demonstrated. The use of spectral analysis to correct variance (turbulence intensity) and covariance (shear stress) estimates obtained from records contaminated by narrow-band noise is also illustrated.  相似文献   

AN EVALUATION OF FRACTAL DIMENSIONS TO QUANTIFY CHANGES IN THE MORPHOLOGY OF FLUVIAL SUSPENDED SEDIMENT PARTICLES DURING BASEFLOW CONDITIONS     

DIRK H. DE BOER 《水文研究》1997,11(4):415-426

The morphology of suspended sediment particles reflects the origin of the suspended load and any modifying processes that may have occurred during transport and storage in the aquatic system. The objective of this study was to evaluate the use of four fractal dimensions to quantify visually observed changes in the morphology of fluvial suspended sediment particles during baseflow conditions. Samples were collected during summer low flow in a small stream on the Canadian Prairies. Particle morphology data were obtained with a transmitted light microscope, a CCD camera and an image analysis system. The morphology of the particle population was characterized using four fractal dimensions (D, D_K, D₁ and D₂). D was derived from the area–perimeter relationship and showed an increase from 1·26±0·02 on 30 June, to 1·34±0·02 on 4 July, to 1·42±0·01 on 7 July. Visually, the increase in D represented the formation of large particles with intricate shapes and increased perimeters. D_K was determined from the area–rank relationship and varied from 1·86±0·01 on 30 June, to 1·90±0·00 on 4 July, to 1·74±0·00 on 7 July. The decrease in D_K between 4 July and 7 July would indicate a greater concentration of the particle area over a small number of large particles. Although the decrease in D_K is consistent with observed changes in the particle size distributions, D_K should be used with the considerable caution because D_K varied more than one standard error between replicates. D₁ and D₂ were determined from the length–perimeter and length–area relationships, respectively. D₁ proved to be of little value for quantifying changes in particle morphology as it showed little change with time, despite considerable visual changes. D₂ however, was useful, despite some variation between replicates. Over the sampling period, D₂ for the composite data sets showed a steady decrease from 1·74±0·02 on 30 June, to 1·68±0·02 on 4 July, to 1·60±0·01 on 7 July. This change in D₂ indicates that, through time, the larger particles became longer and thinner relative to the smaller ones. This study shows that temporal changes in D, D_K and D₂ were consistent with, and allow quantification of, observed changes in particle morphology. D₁ did not reflect observed morphological changes, and is therefore of little value for this type of study. The changes in particle morphology coincided with an increase in primary production in the form of algae. © 1997 John Wiley & Sons, Ltd.  相似文献   

Use of satellite communication of hydrometric data for the whole of Brazil     

JACQUES CALLEDE  EURIDES DE OLIVEIRA  VALDEMAR S. GUIMARÃES  MAURO S. RODRIGUES 《水文科学杂志》2013,58(6):903-913

Abstract

The difficulties of exploiting the huge Brazilian hydrometeorological network led hydrologists of the Departamento Nacional de Águas e Energie Elétrica (DNAEE—Brazilian Department of Water and Electric Power) to use real time satellite telecommunications to improve network management. Data-gathering satellites, which are perfectly adapted to this network, were first used in 1975 and have interested DNAEE since 1980. Collaboration with ORSTOM permitted an initial evaluation of the technique in 1982. In 1984 DNAEE, together with ORSTOM, was able to set up a 20-station network in the Amazon. The results have been so encouraging that a scheme for 200 stations equipped with telecommunications facilities which use the Brazilian Satélite de Colecta de Dados number 1 (SCD1) satellite is in the final stages. This network will cover the entire country.  相似文献   

Constraints on spatial transference of rainfall-runoff relationships in semiarid basins drained by ephemeral streams     

DIRK H. DE BOER 《水文科学杂志》2013,58(5):491-504

Abstract

Field data on drainage basin response have a characteristic scale which is determined by the size of the basin investigated. As a rule, information obtained at one particular scale can be extrapolated over a limited scale range only. This study identifies the nature of constraints on spatial scale transference in a series of semiarid badland drainage basins ranging in area from < 1 to 202 260 m². Research focussed on the rainfall-runoff relationship during a single rainstorm so that the temporal scale was kept constant. Spatial scale transference between systems of differing scale was restricted by morphological and functional constraints. Morphological constraints are caused by morphological elements present in large scale systems but absent in small scale ones. Functional constraints arise solely from the characteristics of the matter and energy flows in the systems of interest. Limits imposed upon spatial scale transferences by morphological and functional constraints are fuzzy rather than sharp in character.  相似文献   

Pinched between the plates: Armenia's voluminous record of volcanic activity     

Ralf Halama  Khachatur Meliksetian  Ivan P. Savov  Patrick J. Sugden  Krzysztof Sokół 《Geology Today》2020,36(3):101-108

Located in the heart of the Lesser Caucasus mountains, where the Arabian and Eurasian tectonic plates collide, Armenia occupies an exceptional geological position shaped through millions of years of subduction and collision. It is a unique place on the Earth recording extensive intrusive and volcanic activity related to the long-standing continental convergence. The volcanoes of Armenia provide a rare opportunity to study the sources and processes involved in this unusual type of magmatism. More than 500 Quaternary volcanoes have been mapped in Armenia, most of them formed from single eruptive episodes. Among several large composite volcanoes, the mighty Aragats stands out as the largest volcano in Armenia and the region altogether. Volcanic deposits testify to the range of eruptive styles—from the ignimbrites formed in eruptions as explosive and voluminous as any seen globally in the modern era to the enormous fissure-fed lava flows that form the Southern Caucasus flood basalt province, the smallest and youngest Large Igneous Province in the world. Several pre-historical and historical eruptions have been documented, highlighting the potential for future volcanic activity in the region. In recent years, research has focused on the volcanic hazards associated with the Armenian Nuclear Power Plant, located in the foothills of Aragats volcano. This article highlights some of the extraordinary volcanic and intrusive features observed in Armenia and summarizes aspects of recent volcanological and petrological research.  相似文献   

南支槽影响下西藏高原南部3次暴雪天气特征分析   总被引：2，自引：1，他引：1  

罗布坚参  假拉  德庆  白珍  次旦巴桑 《气象》2019,45(6):862-870

利用NCEP/NCAR再分析资料和常规观测资料,对2013年1-2月西藏高原南部3次暴雪天气的环流形势、动力、水汽条件等进行诊断对比分析。结果表明:3次暴雪天气中高纬度均以经向型环流形势为主,从长波槽脊配置可分为长波槽型和横槽型两大类;西太平洋副热带高压偏西偏强、伊朗高压东北发展对南支槽加深和缓慢东移起到关键作用。南支槽区560 dagpm线在30°N以南,并东移至70°E附近或以东时西藏高原南部开始出现暴雪天气;暴雪区附近涡度场变化反映了南支槽强度特征,中高层强辐散对南支槽发展起到重要作用;水汽主要源于阿拉伯海,孟加拉湾水汽对东部降雪起到补充作用,南支槽前高空西南急流对水汽输送起关键作用,同时喜马拉雅山脉的大地形抬升,有利于上升运动和水汽凝结成云;水汽通量、水汽通量散度等变化及中心的移动方向,对降雪的强度、落区和时段具有较好的预报指示意义。  相似文献   

Sedimentation and time‐of‐transition techniques for measuring grain‐size distributions in lagoonal flats: comparability of results     

E. MOLINAROLI  G. DE FALCO  G. MATTEUCCI  S. GUERZONI 《Sedimentology》2011,58(6):1407-1413

A comparative study was performed of three instruments used to measure the grain‐size distribution of thirty sediment samples from shallow lagoonal flats: the hydrometer, the Sedigraph 5100 and the CIS‐1. The hydrometer and Sedigraph are based on sedimentation whereas the CIS‐1 uses the time of transition. The percentage of the samples accounted for by the <8 μm fraction was not affected by the technique used, but this was not the case with the clay fraction (<2 μm). Due to its relative independence from the analytical method applied, the <8 μm fraction can be used in ternary diagram classifications. This fraction also has an environmental significance in coastal lagoons in terms of hydrodynamics, organic enrichment and macrozoobenthos assemblages. The linear relationships obtained in this study may provide useful operational indications for similar studies.  相似文献