The General Situation of Geothermal Resources in Ordos Basin     

DENG Changsheng  ZHANG Yi  XIE Xiaofei  MI Weiwei  MA Qiang  XU Min  SONG Jiaxuan  QIANG Juan 《《地质学报》英文版》2019,93(Z2):164-165

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基于ArcGIS Engine的多幅数字地形图接边算法研究     

曹健  李国忠  徐效波  黄金华  孙晓茹 《测绘与空间地理信息》2010,33(2):76-78

随着社会信息化的发展,作为GIS基础数据的数字地形图在各领域起着越来越重要的作用。但是由于地形图分幅管理的习惯造成地理目标实体被人为分割,所以如何在确保精度的前提下,进行快速、准确、无图幅限制的接边是摆在我们面前的一个课题。本文总结了现有接边算法存在的不足,提出基于单条接边线的缓冲区分析来代替矩形接边线的缓冲区分析,避免地物的重复匹配,充分利用属性约束条件的接边算法。通过减少地物匹配的次数来提高接边的效率,并将其应用于实践,取得了很好的效果。  相似文献   

黑龙江省基础综合省情地理信息系统——构建有关问题的探讨     

李国忠  张萱 《东北测绘》1999,22(3):24-25

本文通过对“黑龙江省综合省情地理信息系统”的介绍,对建立“黑龙江省综合省情地理信息系统”的过程、软件平台选取基础地理数据选择、统计数据录入、数值更新机制建立等问题进行了总结性的探讨。以期对今后的工作和同行位起到一些参考作用  相似文献   

对象关系数据库中的矢量数据集空间叠加方法     

李国忠  孙颖 《测绘与空间地理信息》2007,30(1):109-112

首先对当前空间数据模型的特点进行了评述,指出空间数据的存储方式与空间叠加方案的设计与实现密切相关,然后基于当前流行的对象关系数据模型,提出了将拓扑复合数据结构引入对象关系数据模型的空间叠加设计思想,并结合矢量数据空间叠加的流程和对象关系数据库的特点分析了实现该技术思想的关键技术问题,最后以PostgreSQL数据库管理系统为例,设计了可行的矢量数据集空间叠加方案。  相似文献   

Differences in spatial and seasonal patterns of macrophyte assemblages between a coastal lagoon and the open sea   总被引：2，自引：0，他引：2  

Pérez-Ruzafa A  Hegazi MI  Pérez-Ruzafa IM  Marcos C 《Marine environmental research》2008,65(4):291-314

Although benthic macrophytes must be considered in monitoring programs to establish the ecological status of transitional and coastal waters in the European Union, the patterns of variability in species composition of macrophyte assemblages in Mediterranean coastal lagoons has scarcely been studied. In this work the spatial (both vertical and horizontal) and seasonal dynamics of macrophyte assemblages in a coastal lagoon (Mar Menor) are compared with those of open coastal assemblages in the SW Mediterranean to analyze any biological variability in lagoon assemblages and the factors that determine such variability. Different assemblages, characterized by well defined groups of species, can be described according to their isolation from the open sea and the type of substratum; at the same time, a vertical zonation pattern, similar to that found in all marine communities but more compressed, exists. This implies that when applying the EU Water Framework Directive or assessing environmental impact, a lagoon should not be considered spatially uniform and unique unit but as a mosaic of assemblages.  相似文献   

顾及似大地水准面趋势变化的高程异常拟合方法     

赵保成  李国忠  徐坚  徐健  肖潇 《北京测绘》2022,(11):1449-1454

全球导航卫星系统(GNSS)使用的高程系统为大地高系统,而在我国实际工程中使用的高程系统为正常高系统。为了使GNSS得到的大地高数据直接应用于实际工程中,需要求解出测点的高精度高程异常值,进而将大地高转换至正常高。本文从高程异常曲面拟合过程中的特征点选取角度出发,基于SGG-UGM-2全球重力场模型及移去恢复型曲面拟合方法,提出了一种顾及似大地水准面趋势变化的高程异常拟合方法。经过武汉某沿河实验区实例验证,本文提出的高程异常拟合方法拟合精度损失小,拟合中误差达到±0.014 m,完全满足绝大多数工程测量需求。  相似文献   

Scientific management of Mediterranean coastal zone: a hybrid ocean forecasting system for oil spill and search and rescue operations     

Jordi A  Ferrer MI  Vizoso G  Orfila A  Basterretxea G  Casas B  Alvarez A  Roig D  Garau B  Martínez M  Fernández V  Fornés A  Ruiz M  Fornós JJ  Balaguer P  Duarte CM  Rodríguez I  Alvarez E  Onken R  Orfila P  Tintoré J 《Marine pollution bulletin》2006,53(5-7):361-368

The oil spill from Prestige tanker showed the importance of scientifically based protocols to minimize the impacts on the environment. In this work, we describe a new forecasting system to predict oil spill trajectories and their potential impacts on the coastal zone. The system is formed of three main interconnected modules that address different capabilities: (1) an operational circulation sub-system that includes nested models at different scales, data collection with near-real time assimilation, new tools for initialization or assimilation based on genetic algorithms and feature-oriented strategic sampling; (2) an oil spill coastal sub-system that allows simulation of the trajectories and fate of spilled oil together with evaluation of coastal zone vulnerability using environmental sensitivity indexes; (3) a risk management sub-system for decision support based on GIS technology. The system is applied to the Mediterranean Sea where surface currents are highly variable in space and time, and interactions between local, sub-basin and basin scale increase the non-linear interactions effects which need to be adequately resolved at each one of the intervening scales. Besides the Mediterranean Sea is a complex reduced scale ocean representing a real scientific and technological challenge for operational oceanography and particularly for oil spill response and search and rescue operations.  相似文献   

Distribution, magnitude and characterization of the toxicity of Ukrainian estuarine sediments     

Burgess RM  Konovets IM  Kipnis LS  Lyashenko AV  Grintsov VA  Petrov AN  Terletskaya AV  Milyukin MV  Povolotskii MI  Demchenko VY  Bogoslovskaya TA  Topkin YV  Vorobyova TV  Portis LM  Ho KT 《Marine pollution bulletin》2011,62(11):2442-2462

During the Soviet era, Ukraine was an important industrial and agricultural region of the Soviet Union. This industrial and agricultural activity resulted in contamination of Ukraine’s estuaries with legacy anthropogenic pollutants. Investigations on the toxicological effects of this estuarine contamination have been limited. For this research, we measured the toxicity of contaminated sediments from four Ukrainian estuaries to several aquatic organisms over 3 years. Sediment chemical analyses and whole sediment toxicity identification evaluations (TIEs) were also performed to determine the classes of contaminants contributing to toxicity. Toxic sediments were observed in several of the Ukrainian estuaries and chemical analyses of the sediments demonstrated anthropogenic contaminants were widely distributed. Contaminants were also detected in macrobenthic organisms collected from the sediments. Several lines of evidence, including TIEs, indicated hydrophobic organic chemicals (HOCs) were contributing substantially to observed toxicity. This information can guide environmental managers to prioritize portions of the estuaries requiring remediation.  相似文献   

非迭代大地测量导线     

Ozone  MI 李国忠 《武测译文》1995,(4):41-43

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EDM站微波路径曲率半径     

Ozon.  MI 徐绍铨 《武测译文》1993,(1):15-19

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