基于2002-2018年MODIS数据的黄海叶绿素a时空变化研究

浮游植物作为食物链的基础,对海洋生态系统具有重要影响。黄海作为我国重要的渔场,渔业资源面临枯竭的危险,因此对该区浮游植物进行研究具有重要意义。叶绿素a浓度是反映浮游植物生物量的重要指标。利用谷歌地球引擎平台对2002-2018年的MODIS Aqua叶绿素a浓度数据进行处理,并研究其时空分布与变化特征,然后结合区域气候、水文与地理特征以及海洋表面温度、风速、盐度、光合有效辐射和混合层厚度数据分析了其分布与变化的原因。研究发现:受陆源营养物质输入、近岸上升流以及黄海中央冷水团影响,叶绿素a浓度分布呈现由近岸向黄海中部递减特征;在季风、气候、水文的控制下,受风速、海洋表面温度、光合有效辐射、中央冷水团的影响,叶绿素a浓度的最大值出现在4月份,而最小值出现在6、7月份;受苏北沿岸海域海水污染和水体富营养化影响,沿岸海域盐度明显增加,海州湾叶绿素a浓度增速较大;影响黄海叶绿素a浓度变化的环境因子较复杂,除了部分月份存在显著的相关影响因子外,在全年和各季中不存在主导影响因子。     

Google Earth Engine平台支持下的赣南柑橘果园遥感提取研究

赣南地区是中国柑橘主产区,柑橘种植产业经数十年发展已具较大规模。本文利用Google Earth Engine平台,使用2140景Landsat影像进行像元级融合,重构目标年份季节最小云量影像集,构建多维分类特征集,利用随机森林分类算法,实现了1990、1995、2000、2005、2010和2016年赣南柑橘果园的分布制图。结果表明：利用Google Earth Engine平台可实现大量遥感影像数据的高效处理;最小云量影像合成方法能够有效解决多云多雨地区高质量光学影像获取困难的问题;以最小云量影像合成构建的数据集,使用随机森林分类算法能够有效提取赣南柑橘果园,分类平均总体精度和Kappa系数分别为93.15%和0.90,分类效果良好;赣南柑橘果园面积由1990年9.77 km²扩大为2016年2200.34 km²,2005年以后呈大规模扩张趋势,果园分布由零星分布,逐步形成连片化的聚集分布特点,柑橘果园用地的主要来源为林地、灌丛和耕地。     

Fossilisation of a silica diagenesis reaction front on the mid-Norwegian margin

The diagenetic transformation of biogenic silica from opal-A to opal-CT was recognised on seismic reflection data over an area of 78 × 10³ km² on the mid-Norwegian margin. The opal-A/CT diagenetic boundary appears as a positive, high amplitude reflection that generally cross-cuts the hosting stratigraphy. We demonstrate that it is not a sea bottom simulating reflection (BSR) and also that is not in thermal equilibrium with the present day isotherms. We present arguments that three styles of deformation associated with the opal-A/CT reflection – polygonal faulting, regional anticlines and synclines and differential compaction folding – indicate that the silica diagenesis reaction front is fossilised at a regional scale. Isochore maps demonstrate the degree of conformity between the opal-A/CT reflection and three seismic horizons of Late Miocene to Early Pliocene age that potentially represent the paleo-seabed when ‘fossilisation’ of the reaction front took place. The seismic interpretational criteria for recognition of a fossilised diagenetic front are evaluated and the results of our study are integrated with previous studies from other basins of the NE Atlantic in order to determine if the arrest of silica diagenesis was diachronous along this continental margin.     

在线地图的空间认知研究

作为一种新的空间信息认知工具,在线地图适时性强,传播方便。文章总结了在线地图的特点和使用方式,并以交通查询为例分析了用户使用在线地图的地图信息认知过程、信息获取的阶段并根据以上分析得出了在线地图空间认知的一般规律。为数字环境下的空间信息表达与认知提供了理论依据。     

乡镇规划制图的探讨

本文对地图制图如何为城乡规划与建设服务进行了初步探讨。重点放在乡镇规划图的选题上,应从点和面两个不同方面进行考虑。     

A New Approach for Border Detection of the Dumluca (Turkey) Iron Ore Area: Wavelet Cellular Neural Networks

Anomaly analysis is used for various geophysics applications such as determination of geophysical structure's location and border detections. Besides the classical geophysical techniques, artificial intelligence based image processing algorithms have been found attractive for geophysical anomaly analysis. Recently, cellular neural networks (CNN) have been applied to geophysical data and satisfactory results are reported. CNN provides fast and parallel computational capability for geophysical image processing applications due to its filtering structure. The behavior of CNN is defined by two template matrices that are adjusted by a properly supervised learning algorithm. After training stage for geophysical data, Bouguer anomaly maps can be processed and analyzed sequentially. In this paper, CNN learning and processing capability have been improved, combining Wavelet functions and backpropagation learning algorithms. The new architecture is denoted as Wavelet-Cellular Neural networks (Wave-CNN) and it is employed to analyze Bouguer anomaly maps which are important to extract useful information in geophysics. At first, Wave-CNN performance is tested on synthetic geophysical data, which are created by a computer environment. Then, Bouguer anomaly maps of the Dumluca iron ore field have been analyzed and results are reported in comparison to real drilling results.     

内力线定性描绘应力场方法及其在地质构造研究中的应用

为了简化地质构造力学分析，本文探讨了用内力线来描绘应力场的方法，仿照用磁力线描绘磁场的做法，约定以从外力作用点，支承点等处发出的一族主应力迹线为代表内力传递路径的“内力线”，根据弹性理论绘制了部分简单应力场的内力线图，阐述了以简单应力场内力线图为基础绘制复杂应力场内力线图并对之进行分析的方法，同时，文中还对这一方法在山字型构造体系和断裂等板内构造应力场分析，隐伏或未知构及地质的推测，地震预报等方面的应用做了尝试。     

Self-organised clustering for road extraction in classified imagery

The extraction of road networks from digital imagery is a fundamental image analysis operation. Common problems encountered in automated road extraction include high sensitivity to typical scene clutter in high-resolution imagery, and inefficiency to meaningfully exploit multispectral imagery (MSI). With a ground sample distance (GSD) of less than 2 m per pixel, roads can be broadly described as elongated regions. We propose an approach of elongated region-based analysis for 2D road extraction from high-resolution imagery, which is suitable for MSI, and is insensitive to conventional edge definition. A self-organising road map (SORM) algorithm is presented, inspired from a specialised variation of Kohonen's self-organising map (SOM) neural network algorithm. A spectrally classified high-resolution image is assumed to be the input for our analysis. Our approach proceeds by performing spatial cluster analysis as a mid-level processing technique. This allows us to improve tolerance to road clutter in high-resolution images, and to minimise the effect on road extraction of common classification errors. This approach is designed in consideration of the emerging trend towards high-resolution multispectral sensors. Preliminary results demonstrate robust road extraction ability due to the non-local approach, when presented with noisy input.     

中国国家自然地图集Internet版的设计和研制

本文系统阐述了国家自然地图集Ｉｎｔｅｒｎｅｔ版的设计和研制过程中的若干问题,包括系统的概念设计、系统开发中的ＷｅｂＧＩＳ技术和策略,系统的主要功能和特色,以及系统维护和更新方案等。本系统从概念设计来看分为服务器端软件模块、浏览器端软件模块、国家自然地图集数据库支持等几个部分。系统开发中采取的ＷｅｂＧＩＳ技术和策略有:兼顾服务器端和客户端的综合型ＷｅｂＧＩＳ策略,基于Ｊａｖａ Ａｐｐｌｅｔ的 ＷｅｂＧＩＳ浏览器开发技术,基于Ｍａｐ Ｏｂｊｅｃｔ(ＭＯ)的ＷｅｂＧＩＳ服务器开发技术等３个方面。在系统的主要功能特色方面,本文从以下５个方面进行了论述:科学有序的内容结构、清晰精练并带导航的界面、富有特色的信息查询功能、多重表达的地图可视化效果、一定的空间信息分析和制图功能。在系统维护和更新方案上,本文从网络技术、数据更新、功能开发３个方面介绍了计划,并对今后的发展趋势进行了展望。