贵州省国土资源执法监察监管系统建设与应用

针对贵州省山地居多、生态环境脆弱、交通通讯不发达,人力资金相对不足等现状,研究建设了在线、离线相结合,内业、外业相协同,"省、市、县、乡"四级一体化应用,涵盖"线索发现、问题分析、外业核查、立案查处"全流程的国土资源执法监察监管系统。系统突破了高效、高精度、多模式的国土资源执法监察监管的系列关键技术方法,建立了国土资源监察监管系统与"一张图"平台一体化集成应用的新模式,已经部署应用到贵州省国土资源执法局和9个市州国土局和若干区县国土局。实践表明系统可以节省大量的国土资源执法人力、物力和时间,有效提升贵州省国土资源执法监察监管的效率和水平。     

Scale Effects on Chlorophyll-A Concentration Retrieved: Assessment and Validation Using Indian Remote Sensing Satellite

To understand the scale effects on chlorophyll-a (chl-a) concentration retrieved from satellite images, the two-band algorithm (TA) and three-band algorithm (TBA) were constructed for estimating chl-a from satellite images. Two synchronous images of Advanced Wide-Field Sensor (AWiFS) and Linear Imaging Self-Scanner (LISS) of Indian remote sensing satellite were used to assess and validate the scale errors of these two algorithms. They were collected at local time 02:55:46:471 and 02:58:25:053 on October 8, 2005 in Yellow River Estuary, and their spatial resolutions are 24 m and 56 m, respectively. From the results of this study, it was found that: (1) the relative scale error (RSE) of TA and TBA, caused by scale changing from LISS to AWiFS, varied from 0% to 100%; (2) the RSE was correlated with the spatial non-homogeneous degree of chl-a distribution; and (3) using TBA to estimate chl-a concentration in Yellow River Estuary decreased 2.55% of model uncertainty, but increased 4.97% of scale errors, in comparison with TA. Additionally, the study indicated that the performance of algorithms for chl-a estimation was greatly affected by the scale error. If the scale effects of chl-a retrieval algorithm were taken into consideration, TA had a superior performance to the TBA in this study.     

青藏高原形变对中国西部边界的影响

基于青藏高原GPS形变1991-1999年间的测量成果,通过对中尼(中国与尼泊尔)、中印(中国与印度)边界及中不(中国与不丹)边界附近GPS测站地壳水平运动速率的统计分析,运用平均速度法估算了近10a西部边境地区的形变面积。初步计算结果表明,青藏高原形变对我国西部边界存在影响,在1991-1999年之间西部边界的不均匀形变导致国土面积缩小0.37km2。     

地图投影变换浅析

通过研究得出,将地球上各种地理事物与现象表示到平面上,需要采取一系列数学变换,才能使地面上的点与平面上的相应点建立起对应关系,从而才有可能反映出它们的位置、距离、方向、面积、形状及数量大小关系。地图之所以能在平面上反映出球面上事物与现象的空间准确位置和相互关系,就是由于它经过了地图投影的转换。通过研究地图投影变换问题,可以为基于离散网格的数据管理和建模应用提供很好的投影变换基础。     

新媒介环境下政府信息公开研究

媒介是传递信息的载体,传统意义上是指报刊、广播、电视等媒介,随着传播新技术的发展,出现了以互联网络、手机为代表的新媒介。与传统媒介相比,新媒介有其不同的涵义和特点,对政府信息公开工作产生着重要影响。本文从新媒介的概念和特点出发,分析了新媒介对政府信息公开的影响,阐述了新媒介环境下如何做好政府信息公开工作,最后提出在新媒介环境下对国土资源政府信息公开的几点思考和建议。     

Revealing the spatiotemporal characteristics of the general public's panic levels during the pandemic crisis in China

The existing crisis management research mostly reveals the patterns of the public's panic levels from the perspectives of public management, sociology, and psychology, only a few studies have revealed the spatiotemporal characteristics. Therefore, this study investigates the spatial distribution and temporal patterns and influencing factors on the general public's panic levels using the Baidu Index data from a geographic perspective. The results show that: (1) The public's panic levels were significantly correlated with the spatial distance between the epicenter and the region of investigation, and with the number of confirmed cases in different regions when the pandemic began to spread. (2) Based on the spatial distance between the epicenter and the region, the public's panic levels in different regions could be divided into three segments: core segment (0–500 km), buffer segment (500–1300 km), and peripheral segment (>1300 km). The panic levels of different people in the three segments were consistent with the Psychological Typhoon Eye Effect and the Ripple Effect can be detected in the buffer segment. (3) The public's panic levels were strongly correlated with whether the spread of the infectious disease crisis occurred and how long it lasted. It is suggested that crisis information management in the future needs to pay more attention to the spatial division of control measures. The type of crisis information released to the general public should depend on the spatial relationship associated with the place where the crisis breaks out.     

顾及用户体验的三维城市模型自适应组织方法

传统基于“图层付象”的组织方法,没有考虑三维城市模型的不同内容以及不同细节层次的粒度差异,导致在网络环境下的传输效率低,难以满足多用户并发访问的流畅可视化。深入分析了大范围漫游与小范围聚焦的用户体验特点,通过元数据统筹管理和对象离散化,即时响应用户请求,减少无效数据传输,保证了多用户并发环境下的高效调度和浏览。针对模型LoI)和分解的对象,设计了结构统一的对象ID,隐式存储关联关系并支持分布式模型存储管理。以分布式数据库MongoDB为平台进行实验,验证了本文方法的可行性和有效性。     

一种新的近似平行沟渠群的典型化方法

提出并实现了一种针对近似平行沟渠群的典型化方法。首先,建立沟渠的方位关系图,通过生成关系图中各连通分量的极大完全子图,提取近似平行的沟渠;然后,依据视觉认知规律定义沟渠间的认知距离,并基于最小生成树的剪枝对沟渠进行分组;接着,运用K-means ++算法对分组后的沟渠进行重新表达;最后,通过比较综合前后沟渠群的外轮廓相似性以及沟渠分布密度的差异,对典型化结果进行了评价。对广州市数据进行了实验,结果表明该方法能有效进行近似平行的沟渠群的典型化。     

The determination of potential difference by the joint application of measured and synthetical gravity data: a case study in Hungary

In an elementary approach every geometrical height difference between the staff points of a levelling line should have a corresponding average g value for the determination of potential difference in the Earth’s gravity field. In practice this condition requires as many gravity data as the number of staff points if linear variation of g is assumed between them. Because of the expensive fieldwork, the necessary data should be supplied from different sources. This study proposes an alternative solution, which is proved at a test bed located in the Mecsek Mountains, Southwest Hungary, where a detailed gravity survey, as dense as the staff point density (~1 point/34 m), is available along a 4.3-km-long levelling line. In the first part of the paper the effect of point density of gravity data on the accuracy of potential difference is investigated. The average g value is simply derived from two neighbouring g measurements along the levelling line, which are incrementally decimated in the consecutive turns of processing. The results show that the error of the potential difference between the endpoints of the line exceeds 0.1 mm in terms of length unit if the sampling distance is greater than 2 km. Thereafter, a suitable method for the densification of the decimated g measurements is provided. It is based on forward gravity modelling utilising a high-resolution digital terrain model, the normal gravity and the complete Bouguer anomalies. The test shows that the error is only in the order of 10⁻³mm even if the sampling distance of g measurements is 4 km. As a component of the error sources of levelling, the ambiguity of the levelled height difference which is the Euclidean distance between the inclined equipotential surfaces is also investigated. Although its effect accumulated along the test line is almost zero, it reaches 0.15 mm in a 1-km-long intermediate section of the line.     

Using gravity and topography-implied anomalies to assess data requirements for precise geoid computation

Many regions around the world require improved gravimetric data bases to support very accurate geoid modeling for the modernization of height systems using GPS. We present a simple yet effective method to assess gravity data requirements, particularly the necessary resolution, for a desired precision in geoid computation. The approach is based on simulating high-resolution gravimetry using a topography-correlated model that is adjusted to be consistent with an existing network of gravity data. Analysis of these adjusted, simulated data through Stokes’s integral indicates where existing gravity data must be supplemented by new surveys in order to achieve an acceptable level of omission error in the geoid undulation. The simulated model can equally be used to analyze commission error, as well as model error and data inconsistencies to a limited extent. The proposed method is applied to South Korea and shows clearly where existing gravity data are too scarce for precise geoid computation.