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   

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