The Statistical Analysis of Migration of Strong Earthquakes-Taking the North China Region as an Example

The migration of strong earthquakes is an important research topic because the migration phenomena reflect partly the seismic mechanism and involve the prediction of tendency of seismic activity. Research on migration of strong earthquakes has mostly focused on finding the phenomena. Some attempts on getting regularity were comparatively subjective. This paper suggests that there should be indices of migration in earthquake dataset and the indexes should have statistical meaning if there is regularity in the migration of strong earthquakes. In this study, three derivative attributes of migration, i.e., migration orientation, migration distance and migration time interval, were statistically analyzed. Results in the North China region show that the migration of strong earthquakes has statistical meaning. There is a dominant migration orientation (W by S to E by N), a dominant distance (≤100km and on the confines of 300～700km), and a dominant time interval (≤1a and on the confines of 3～4a). The results also show that the migration will differ slightly with different magnitude range or earthquake activity phase.     

中国兴凯湖北岸平原晚全新世花粉记录及泥炭沼泽形成

通过兴凯湖北岸平原泥炭剖面高分辩率花粉分析研究，对晚全新世花粉划分4个组合带。XKH-4组合时期(1857～1746aB．P．)为沼泽发育前期，这一时期花粉浓度小，陆生草本植物占优势，气候干冷。XKH-3组合时期(1746～1287aB．P．)为沼泽发育早期，这一时期花粉浓度较大，且水生植物花粉含量为剖面最高，喜温落叶阔叶植物大发展时期，气候温和湿润。XKH-2组合时期(1287～602aB．P．)为沼泽发育中期，这一时期花粉浓度最小，但以陆生草本植物为主，木本植物为辅，水生植物急剧减少，针叶植物出现两次高峰，气候向冷干方向发展。XKH-1组合时期(602aB．P．至今)为沼泽发育盛期，这一时期花粉浓度最大，陆生草本植物大发展时期，气候波动较大。     

Post-depositional modification of NO-3 in snow layers at EastAntarctica and at the headwater of ürumqi River

Acidic species, such as Nitrate, in polar snow and firn layers are “reversibly” deposited, and are sufficiently volatile to undergo significant postdepositional exchange between snow/firn and the atmosphere. Through comparison of the snowpit and snowpack nitrate concentrations from central East Antarctica and the headwater of ürumqi River, we conclude that the nitrate peaks in the uppermost surface snow layers in central Antarctica are not related to an atmospheric signal and must account for post-depositional effects. Such effects, however, are not found in the surface snowpack nitrate profiles from the headwater of ürumqi River. Two reasons may account for the post-depositional difference. At first, nitrate in the polar snow and firn layers appears to be hydrated ion, which can be taken up by the atmosphere, while at the headwater of ürumqi River it seems mainly as mineral ion, which assembles the behavior of aerosol-derived species that are “irreversibly” deposited and do not undergo significant post-depositional exchange with the atmosphere. Secondly, the chemical features of the snow and ice on the Antarctica are mainly determined by wet deposition, to the contrary, dry deposition is more significant at the headwater of lUrumqi River than that on the East Antarctic Plateau.     

火山岩与地形联合约束下海岛土壤稀土元素地球化学空间分布异质性——以广西涠洲岛为例

海岛土壤地球化学特征的研究对于认识海岛表生地质环境有重要意义。本研究以我国最大的第四纪火山海岛——涠洲岛为案例,重点研究亚热带海岛环境下火山岩风化土壤的稀土元素（REE）地球化学特征,并探讨影响其空间分布的关键因素。结果表明,涠洲岛土壤REE总量（ΣREE）自然变化范围较大,介于59.07~575.30 mg/kg,平均值为285.53 mg/kg,高于中国大陆土壤背景值（163.86 mg/kg）,指示火山岩风化海岛具有较高的土壤REE丰度。反距离权重插值法（IDW）分析指示,岛内土壤的REE含量高低变化呈现出以带状和斑块状为主体形态的空间分布不均一性,推断其成因与母质岩石类型和地形位置等因素密切相关。3种不同岩性的成土母岩的ΣREE含量变化序列为：玄武岩（236.66 mg/kg）>火山碎屑岩（215.58 mg/kg）>含生物碎屑海滩沉积物（18.99 mg/kg）,对应的土壤ΣREE含量具有类似变化规律,即玄武岩土壤（307.20 mg/kg）>火山碎屑岩土壤（297.46 mg/kg）>含生物碎屑海滩沉积物土壤（89.73 mg/kg）。该证据指示母岩是控制岛内土壤REE含量变化的首位因素,玄武岩整体上易形成具有较高REE丰度的土壤,火山碎屑岩次之,而含生物碎屑海滩沉积物反之。此外,本研究还发现火山碎屑岩单一岩性区内,发育的土壤REE含量也会随地形地貌差异而出现显著变化,其原因是地形地貌制约了土壤矿物和化学风化程度,海蚀丘陵比海积平原更利于海岛土壤中REE次生富集作用的发生。

     

基础地理信息应用服务研究

本文全面、系统地分析了基础地理信息在地理信息产业中的作用、基础地理信息的各种应用，并在此基础上提出了基础地理信息的服务策略。     

地铁控制基标归化改正原理及编程实现

介绍了控制基标在地铁建设中的作用和测设步骤,总结了铺轨基标归化改正计算的理论依据和基本计算方法,建立了数学模型。同时在VB6.0环境下编程,实现了归化改正点位的自动判定以及改正值的自动计算,介绍了编程原理,并提供了流程图及工程实例。     

从大模型看测绘时空信息智能处理的机遇和挑战

当前,时空信息、定位导航服务已成为重要的新型基础设施,在通用人工智能的驱动下,大模型引领的智能时代已经到来,越来越强大的大模型将在测绘时空信息智能处理与应用中发挥越来越重要的作用。以大模型为研究范式,总结大模型在测绘时空信息智能处理的现状与进展,分析大模型在测绘时空信息智能处理面临的挑战,阐述多模态融合与理解架构设计、提示工程优化微调以及人在回路引导决策3个核心方面在时空信息测绘大模型中的关键作用。针对行业理解深度、数据安全隐患、内容可信度保障以及训练部署成本优化4个方面,展望时空信息测绘大模型面临的挑战与发展趋势。

     

《遥感图像处理》课程教学在地理学专业中的探索与实践

针对地理专业的自身特点和当前遥感图像处理的教学现状，提出了遥感图像处理课程在地理专业中的主要教学内容框架、教学方法以及教学改革方向，并对该课程的实践教学部分做了重点介绍，最后论述了该课程在地理学专业实践教学中的取得一些教改成果。     

土地利用动态遥感监测数据库标准探讨

为了将土地利用动态遥感监测技术和成果进一步普及和应用,规范土地利用动态遥感监测数据库建设,依据国土资源信息化标准建设的总体部署和要求,参考相关标准和规程,结合土地利用动态遥感监测业务特点,制定了土地利用动态遥感监测数据库标准草案。