Morphology‐based modeling of aggregation effect on the patch area size for GlobeLand30 data

Currently, research on the scale effect mainly concentrates on revealing and describing the phenomenon; little work has been done to model the scaling of analysis indicators along with the scale change of the data. Such models can help explain and estimate the scale effect and are thus of great interest. As patch morphology significantly influences patch evolution over data scale transformation, this study proposes a model that applies patch morphology metrics to explain and estimate the change in the patch and category area ratio in the upscaling of raster categorical data. In the experimental evaluation, area scaling of GlobeLand30 data under majority aggregation is studied intensively. Two metrics—the ratio of the patch area after aggregation to its original area and the ratio of the category area after aggregation to its original area—are used in this evaluation. The experimental results indicate that this model can adequately describe the pattern of the patch area change and precisely estimate the category area change arising from the resolution change. It is also demonstrated that the spatial distribution of patches has much less influence on the change in the category areas compared with the patch morphology. Additionally, the modeling approach in this study may also be adopted to investigate the scaling of other landscape metrics.     

The scheme for the database building and updating of 1∶10 000 digital elevation models

The National Bureau of Surveying and Mapping of China has planned to speed up the development of spatial data infrastructure (SDI) in the coming few years. This SDI consists of four types of digital products, i. e., digital orthophotos, digital elevation models, digital line graphs and digital raster graphs. For the DEM, a scheme for the database building and updating of 1∶10 000 digital elevation models has been proposed and some experimental tests have also been accomplished. This paper describes the theoretical (and/or technical) background and reports some of the experimental results to support the scheme. Various aspects of the scheme such as accuracy, data sources, data sampling spatial resolution, terrain modeling, data organization, etc are discussed.     

林地景观点格局的样带梯度分布与空间聚集特征——以重庆三峡库区生态屏障区为例

从点格局角度研究林地及其不同类型景观格局的空间分布特征,以探求空间异质性在林地景观中的连续变化和分布趋势.选取点格局密度和RipleyK函数,建立重庆库区生态屏障区不同样带和1997-2005年间林地景观的点格局数据库,以此分析林地及其3种不同类型景观的样带梯度分布和空间聚集特征变化.结果表明:①研究区林地景观点格局的样带梯度分布在整体上表现出空间极不均衡特征,中心点上游林地景观点格局密度呈“双峰”梯度空间分布特征,下游呈“阶梯”梯度空间分布特征;②在各级空间尺度和时间变化上,屏障区林地景观格局都表现出局部空间聚集分布,与1997年相比,2005年林地分布范围在扩张,且空间分布均匀程度在提高,而空间聚集分布的特征在减弱;③有林地景观空间聚集特征与整体林地景观接近一致,有林地的基质优势在减弱.灌木林地分布在空间上比有林地更为集聚,在时间上聚集程度也在加强.疏林地由于在空间上扩张速度快致使其空间聚集发生减弱,空间分散性更大.     

Quantitative measures for spatial information of maps

The map is a medium for recording geographical information. The information contents of a map are of interest to spatial information scientists. In this paper, existing quantitative measures for map information are evaluated. It is pointed out that these are only measures for statistical information and some sort of topological information. However, these measures have not taken into consideration the spaces occupied by map symbols and the spatial distribution of these symbols. As a result, a set of new quantitative measures is proposed, for metric information, topological information and thematic information. An experimental evaluation is also conducted. Results show that the metric information is more meaningful than statistical information, and the new index for topological information is more meaningful than the existing one. It is also found that the new measure for thematic information is useful in practice.     

断层相关裂缝定性识别：原理与应用

介绍一种定性识别和预测断层相关裂缝的新方法-断面脱空法。该方法以断面脱空理论为基础,通过建立断面脱空空间与断层相关裂缝之间的置换模型,从而实现通过观察断层形迹开展地下断层相关裂缝的定性识别。以塔中Ⅰ号断裂带西侧中古3、塔中72两个井区下奥陶统良里塔格组（O₃l）为例,基于地震资料分别开展剖面和平面上的断层相关裂缝识别,并将预测结果与钻井、测井及地震属性分析获得的裂缝发育特征进行对比研究。结果表明:利用断面脱空原理预测结果与钻测井揭示结果基本一致,与根据均方根检测的裂缝平面分布对比,细节上有差异,但总体特征基本一致,表明利用断面脱空原理可以定性地对断层相关裂缝做出预测。断面脱空理论的提出不仅为定性评价地表、地下断层相关裂缝发育分布规律提供一种新思路,更为定量表征断层相关裂缝提供重要的理论依据。     

利用Google Earth建立等高线三维地形模型

GoogleEarth提供的免费地理坐标数据,可以作为CFD软件地形几何建模的数据源。通过C#编程提取Google Earth提供的高程数据,应用Global Mapper V11.0、Rhino 5.0等三维建模软件自动实现三维地形图几何建模,该方法简单实用,能满足CFD计算要求。     

班公湖—怒江成矿带商旭造山型金矿床Ⅲ号矿段深部找矿潜力研究

西藏双湖县商旭造山型金矿床位于班公湖—怒江缝合带中段,矿体受NWW向的脆—韧性断裂构造控制,呈似层状、脉状产于中—下侏罗统木嘎岗日群混杂岩中。围岩为炭质板岩、变石英砂岩等。矿石类型主要为石英脉型和构造蚀变岩型,矿石构造以细脉状和角砾状为主,矿石矿物为自然金。矿床学与同位素地球化学研究认为木嘎岗日群含金建造为商旭金矿提供了主要物质来源,NWW向脆—韧性断裂构造为含金热液的运移和金的沉淀供了运输通道和就位空间,羌塘南缘早白垩世构造—岩浆活动为含金热液的运移提供了热动力,矿区内NWW向构造破碎带中变形强烈,具黄铁矿化、硅化蚀变的地段,为本矿区的找矿有利地区。土壤地球化学调查显示,Ⅲ号矿段南部,T-4、T-5异常区域具有较好的找矿潜力;电法测深资料显示,Ⅲ号矿段的控矿构造在深部还有延伸,并可能与区域较深大的断裂相连。综合分析认为,Ⅲ_(1-2)号矿体在标高4200m以下还具有较大的找矿潜力,通过进一步地质勘查工作,有望提高金资源量,扩大矿床规模。同时,初步总结了商旭造山型金矿床"找矿三步组合拳"的勘查工作方法。     

海洋标准计量质量工作中建立创新机制对策初探

海洋标准计量质量工作是海洋事业不断发展的基础性和保障性工作,原始创新能力及其保障机制在技术水平和服务能力的提升中发挥着关键作用。文章结合海洋标准计量质量一线工作,分析当前科研和技术创新现状,构建指标体系对创新发展能力进行评价研究,并尝试从加大对基础研究和应用技术研究的投入力度、建立与科研创新相适应的评价制度和激励机制、强化科研团队建设和人才培养3个方面开展创新机制建设对策研究。     

协因数阵秩亏时扩建网极大条件密度估计的精度

作者曾〔3〕推导了当联系参数函数不独立时,扩建网极大条件密度估计的等价法方程和参数的协因数矩阵。在其基础上,本文作者继续推导单位权方差因子的估计公式。     

粤港澳大湾区一次局地极端强降水过程的多尺度观测特征与演变分析

2020年5月22日凌晨粤港澳大湾区发生了一次极端强降水过程,最大小时雨量和3小时雨量打破广东省内“龙舟水”期间的历史最高纪录。利用多源观测数据以及ERA5再分析资料对引发局地极端降水的中尺度对流系统(MCS)的演变过程与中尺度特征开展研究。(1)此次强降水过程主要集中在凌晨时段,具有持续时间短、局地雨强极端、累积雨量大等特点,在3小时的降水过程中出现了两个降水峰值。(2)这次过程为一次暖区暴雨过程,低层西南季风提供了充足的暖湿水汽,低涡切变线提供了良好的抬升条件。中α尺度季风云团呈准静止状态并升尺度增长为MCC(中尺度对流复合体)的过程引发了大湾区夜间局地的极端降水。(3)过程中两个阶段的峰值降水与中γ尺度对流单体生消发展期间的传播与移动矢量发生的改变有密切联系。数个中γ尺度对流单体构成多单体风暴形态,呈西北-东南侧向排列,这些单体先后触发发展并有着各自的地面辐合线。对流单体在环境风引导下向偏东南方向移动引发第一阶段峰值降水。随后不同单体的辐合线连接,对流向西南方向传播显著加快,使对流系统移动矢量发生改变,因而造成第二阶段峰值降水。(4)造成两段峰值降水的中γ尺度对流单体结构存在明显...