共查询到18条相似文献，搜索用时 103 毫秒
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Delaunay三角剖分的快速实现 总被引：12，自引：0，他引：12
主要探讨了以Delaunay三角剖分的逐点插入法为基础构建不规则三角网的方法，并在程序设计中对该算法进行了改进，极大地提高了Delaunay三角网的构建效率。 相似文献
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床面冲淤计算机处理方法 总被引：2，自引：0，他引：2
冲淤计算是河流，河口，海岸等水域中分析，预测床面变化的基础，利用非结构网络自动剖分技术形成覆盖计算区域的三角网，能较好地适应边界和特殊地形，基于高程内插建立三角网数字高程模型，采用垂直三棱柱体作为基本单位计算不同时段冲淤量，从而提高计算精度，通过网络剖分，利用在计算区域内任意选择子域进行淤量的计算和分析。同时将生成的非结构网格直接有于二维床面冲淤数学模型，便于对每个节点的计算结果进行检证以提高模型的可靠性。 相似文献
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复杂区域内自动联结三角网方法研究 总被引：2，自引：0，他引：2
本文对传统的自动联结三角网方法进行了改进，建立了区域的内、外边界，在三角形网的扩展中增加了边界限制，将自动联结三角网方法推广到凹多边形区域和多联通区域，提高了联网速度。 相似文献
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一种基于TIN三角网数据的规则格网生成算法 总被引：2，自引：0，他引：2
格网地形模型和7TIN地形模型是数字高程模型的两个主要组成部分。结合实际工作，在实现多分辨率地形环境仿真需求下，充分利用已知TIN数据信息，通过划分格网点，判断格网点是否落在TIN三角网内，用三角形三个点高程内插得到格网点高程的方法，实现基于TIN数据生成格网数据。方法简单实用，在三维地形仿真应用中有较好的效果。 相似文献
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本文通过对Delaunay三角网的利用和对TIN(Triangulated Irregular Network不规则地形三角网)的化简方法实现了对海图中特征水深注记的选取;并在此基础上建立了具有水深注记分区选取、人机交互选取水深注记、菱型网设置、三角网检测等多项功能的海图水深注记自动综合子系统。 相似文献
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1985年1月至2月，我国南大洋科学考察队从阿氏网和三角网中采获一些头足类标本，经分类鉴定，共1科1亚科1属3种。 相似文献
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胶州湾中肋骨条藻赤潮与环境因子的关系 总被引：55，自引：13，他引：55
1998年7月3－8日胶州湾女增养残海域发生一次中肋骨条藻（Skketonemacostatum)赤潮，对该次赤潮生消全过程环境因子变化的监测分析表明，该养殖海域表层水体解态无机氮，无机磷，可溶性铁和锰含量高，为赤潮的发生提供了必需的营养基础，6月30日－7月1日较强的降雨过程使不体在以后两天中形成了高温，低盐，富营养的环境，有利于中肋骨条藻快速增殖拉导致了赤潮的爆发，7月3－8日天气持续的高温和静风使赤潮得以维持，随后磷，硅的耗尽使赤潮逐步走向消亡，应用相关分析和主成分分析，研究了赤潮与环境因子的关系，结果表明，影响本次赤潮的重要环境因子有：盐度，水温，硅酸盐，磷酸盐。 相似文献
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胶州湾北部水层-底栖耦合生态系统的动力数值模拟分析 总被引：13，自引：2，他引：13
基于胶州湾1995年5航次的生态动力学综合实验观测，建立了一个水层－底栖生态系耦合的动力学箱式模型，其中水层亚模型包括浮游植物、浮游动物、无机氮、无机磷以及DOC、POC和溶解氧7变量，底栖部分包括大型、小型底栖生物、细胞、碎屑及无机氮和磷6变量。模型考虑了海面太阳辐照度变化、海水及底泥温度变化，以及营养盐与DOC陆源流入的影响，利用该模型成功地模拟了胶州湾北部各生态变量的季节变化特征。同吴增茂等（1999）水层模型模拟结果相比可以看出，耦合模型的结果更加合理。 相似文献
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This article evaluates different spatial interpolation methods for mapping submerged aquatic vegetation (SAV) in the Caloosahatchee Estuary, Florida. Data used for interpolation were collected by the Submersed Aquatic Vegetation Early Warning System (SAVEWS). The system consists of hydro-acoustic equipment, which operates from a slow-moving boat and records bottom depth, seagrass height, and seagrass density. This information is coupled with geographic location coordinates from a Global Positioning System (GPS) and stored together in digital files, representing SAV status at points along transect lines. Adequate spatial interpolation is needed to present the SAV information, including density, height, and water depth, as spatially continuous data for mapping and for comparison between seasons and years. Interpolation methods examined in this study include ordinary kriging with five different semivariance models combined with a variable number of neighboring points, the inverse distance weighted (IDW) method with different parameters, and the triangulated irregular network (TIN) method with linear and quintic options. Interpolation results were compared with survey data at selected calibration transects to examine the suitability of different interpolation methods. Suitability was quantified by the determination coefficient (R2) and the root-mean-square error (RMSE) between interpolated and observed values. The most suitable interpolation method was identified as the one yielding the highest R2 value and/or the lowest RMSE value. For different geographic conditions, seasons, and SAV parameters, different interpolation methods were recommended. This study identified that kriging was more suitable than the IDW or TIN method for spatial interpolation of all SAV parameters measured. It also suggested that transect data with irregular spatial distribution patterns such as SAV parameters are sensitive to interpolation methods. An inappropriate interpolation method such as TIN can lead to erroneous spatial representation of the SAV status. With a functional geographic system and adequate computing power, the evaluation and selection of interpolation methods can be automated and quantitative, leading to a more efficient and accurate decision. 相似文献
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This article evaluates different spatial interpolation methods for mapping submerged aquatic vegetation (SAV) in the Caloosahatchee Estuary, Florida. Data used for interpolation were collected by the Submersed Aquatic Vegetation Early Warning System (SAVEWS). The system consists of hydro-acoustic equipment, which operates from a slow-moving boat and records bottom depth, seagrass height, and seagrass density. This information is coupled with geographic location coordinates from a Global Positioning System (GPS) and stored together in digital files, representing SAV status at points along transect lines. Adequate spatial interpolation is needed to present the SAV information, including density, height, and water depth, as spatially continuous data for mapping and for comparison between seasons and years. Interpolation methods examined in this study include ordinary kriging with five different semivariance models combined with a variable number of neighboring points, the inverse distance weighted (IDW) method with different parameters, and the triangulated irregular network (TIN) method with linear and quintic options. Interpolation results were compared with survey data at selected calibration transects to examine the suitability of different interpolation methods. Suitability was quantified by the determination coefficient (R2) and the root-mean-square error (RMSE) between interpolated and observed values. The most suitable interpolation method was identified as the one yielding the highest R2 value and/or the lowest RMSE value. For different geographic conditions, seasons, and SAV parameters, different interpolation methods were recommended. This study identified that kriging was more suitable than the IDW or TIN method for spatial interpolation of all SAV parameters measured. It also suggested that transect data with irregular spatial distribution patterns such as SAV parameters are sensitive to interpolation methods. An inappropriate interpolation method such as TIN can lead to erroneous spatial representation of the SAV status. With a functional geographic system and adequate computing power, the evaluation and selection of interpolation methods can be automated and quantitative, leading to a more efficient and accurate decision. 相似文献