Assessing the suitability of GlobeLand30 for mapping land cover in Germany

Global land cover (LC) maps have been widely employed as the base layer for a number of applications including climate change, food security, water quality, biodiversity, change detection, and environmental planning. Due to the importance of LC, there is a pressing need to increase the temporal and spatial resolution of global LC maps. A recent advance in this direction has been the GlobeLand30 dataset derived from Landsat imagery, which has been developed by the National Geomatics Center of China (NGCC). Although overall accuracy is greater than 80%, the NGCC would like help in assessing the accuracy of the product in different regions of the world. To assist in this process, this study compares the GlobeLand30 product with existing public and online datasets, that is, CORINE, Urban Atlas (UA), OpenStreetMap, and ATKIS for Germany in order to assess overall and per class agreement. The results of the analysis reveal high agreement of up to 92% between these datasets and GlobeLand30 but that large disagreements for certain classes are evident, in particular wetlands. However, overall, GlobeLand30 is shown to be a useful product for characterizing LC in Germany, and paves the way for further regional and national validation efforts.     

Magnetic fabric and emplacement of the post-collisional Pomovaara Granite Complex in northern Fennoscandia

The Proterozoic Pomovaara Granite Complex in northern Finland comprises three separate highly magnetic granite stocks. They are discordant, apparently unfoliated and according to isotope data, a significant Archaean component characterizes the source of these granites. The three stocks are aligned in an array parallel to major trans-crustal faults as interpreted from both aeromagnetic and gravity data. Their younger age of 1.8 Ga, compared to the main tectonic events at 1.9 Ga in northern Fennoscandia, indicates their post-collisional nature with respect to these events. The anisotropy of magnetic susceptibility (AMS) was studied together with magnetic, gravity and geological data in order to assess the emplacement mechanisms of the Pomovaara Granite Complex, and the possible tectonic control of fault systems on the ascent and emplacement of granitic magma. The orientation of magnetic fabrics within the granite stocks indicates that the direction of the original magma upwelling was from the SW, parallel to the major fault zones that controlled, at the crustal scale, the ascent of granite magmas. The predominant NW–SE orientations of the minimum magnetic axes of the magnetic ellipsoid and the elongate shapes of the stocks indicate compression normal to the deep fault trend during the crystallization of the granite magma.     

宋代测绘史考＊

概述宋代测绘管理及机构职官设置,各类测量及地图状况,并介绍当时若干具有世界先进水平的测绘成果。     

Gamma-Ray Data Processing and Integration for Lode-Au Deposits Exploration

A large number of mineral deposits are associated with hydrothermal processes, especially auriferous deposits. In such processes, studies on percolating fluids may indicate the presence of potash (K), among other elements. In this study, aerogammaspectrometric data-processing methodologies are evaluated, especially those methods based on the suppression of the primary contribution of potassium, the result of lithological and soil variations, and to environmental conditions. Resulting maps point out the contribution of hydrothermal K. This processing procedure was used because of the association of hydrothermal K and auriferous mineralizations according to the deposit model defined for the studied region. Intensity maps locate the areas with great influence of hydrothermal K. Data integration required to improve a change in the gammaspectrometric data processing in order to positively correlate hydrothermalised areas. Data integration could distinguish high and medium favorable targets for mineral exploration of lode-Au deposits in the studied region.     

Methodology for Landslide Susceptibility Mapping by Means of a GIS. Application to the Contraviesa Area (Granada,Spain)

This article presents a method to map landslide susceptibility in rock massifs using Geographical Information Systems (GIS). The method is based on making an inventory of rupture zones of different types of slope movements and then analysing the bivariate correlation of these with the factors that determine instability. After determining the factors that present the highest correlation with each type of movement, a matrix is created to combine these factors and to determine the percentage of the rupture zone in each combination, which provides an expression of the susceptibility of the terrain. The map thus obtained is divided into susceptibility classes. The susceptibility maps (made in 1995) for each type of movement are first calibrated with the inventory of the movements from which they are derived (previous to 1995), and subsequently validated by another inventory elaborated after the susceptibility maps (in 1997). In both cases, significant correlation coefficients were obtained (the Goodman–Kruskal coefficients were over 0.8 and sometimes exceeded 0.9). The relative error (degree of accumulated fit for very low to low susceptibility classes) was always less than 5%,while the relative success rate was always above 50%. These resultsillustrate the adequacy of the method and of the maps obtained.     

Overview of a theory and method for prediction of mineral resources in China

A set of theories and methods has long been needed to enhance geological prospecting. Since 1982, we have been predicting mineral-resource potential based on geological research in China, using a comprehensive information theory and method (CIM), developed to identify mineral-resource domains. The key features of CIM are: (1) to establih comprehensive prospecting models on various scales on the basis of a metallogenic model; the prospecting models are statistical in nature and incorporate a range of ore indicators, (2) to compile detailed metallogenic maps that reflect metallogenic regularities, ore-controlling factors, prospecting indicators, and the positions of favorable target areas, and (3) to establish statistical prediction models of undiscovered mineral resources. This CIM method has been effective and has provided significant economic benefits in the past few years in China.     

An empirical evaluation of three elevation change symbolization methods along routes in bicycle maps

ABSTRACT

Elevation change is critical for choosing a route when bicycling. We detail an empirical study in which we comparatively evaluated three linear symbolization types (color hue, color-coded arrows, and elevation profiles) to depict elevation change in bicycle maps for two common bicycle route planning tasks: relative height detection and slope identification. Participants performed most accurately with the color-coded arrows for relative height detection tasks, whereas symbolization did not significantly influence map-use performance for slope identification. Participants preferred the elevation profile, in spite of their lowest performance with this method overall. Our rare empirical findings offer much needed new insights into the function and appropriateness of common elevation symbolization methods, specifically to identify elevation change in bicycle route planning tasks in urban areas where map display real estate is already very limited.     

GIM和不同约束条件相结合的BDS差分码偏差估计

现阶段BDS卫星和地面跟踪站数量较少,用BDS单系统获取的DCB精度有限,针对此问题,本文基于CODE GIM,采用两种不同的"零均值"基准约束方案(分别称为约束1和约束2),选取2015年(DOY002-090)MGEX的BDS数据,求解BDS的DCB,并对其进行精度评估。结果表明,两种约束方案下,卫星DCB差值整体趋势一致,DCBC2I-C7I、DCBC2I-C6I的系统性偏差分别约为-3.3ns和1.2ns,接收机DCB的系统性偏差与卫星DCB大小相同,符号相反。相对于约束1,施加约束2后,IGSO和MEO卫星DCB估值更加稳定(DCBC2I-C7ISTD最大改善21%,DCBC2I-C6ISTD最大改善13%),IGSO和MEO卫星的稳定性(分别在0.1ns和0.2ns左右)优于GEO卫星(0.150.32ns)。约束2的DCB估值效果不仅与CAS/DLR产品有较好的一致性(Bias:-0.40.2ns),而且顾及了BDS卫星DCB间的稳定性差异。两种约束方案下,BDS接收机DCB的STD无明显变化,说明约束的选择对BDS接收机DCB的稳定性无明显影响。BDS接收机DCB稳定性整体上优于1ns,中高纬度区域较好(STD 0.4ns左右),低纬度区域稍差(STD 0.81ns)。     

Long baroclinic Rossby waves with periods of about 500d near 20°N in the northwest Pacific Ocean

1IntroductionThe oceanic Rossby waves play an importantrole in the large-scale oceanic circulations.In the o-ceans baroclinic Rossby waves have surface manifes-tations of just a fewcentimeters,and wavelengths atmid-latitudes of hundreds to thousands of ki…     

Gulf of Mexico sediment sources and sediment transport trends from magnetic susceptibility measurements of surface samples

The magnetic properties from 200 trigger core-top and Van Veen grab sediment samples recovered from throughout the Gulf of Mexico have been analyzed and used to characterize sediment source and flow pattern distributions. Magnetic parameters included are anhysteretic remanent magnetism (ARM) and magnetic susceptibility (MS) measurements. Results from these measurements are compared to previously determined calcium carbonate percentages, and clay and hematite influx trajectories into the Gulf of Mexico for the same samples reported by Balsam and Beeson [Balsam, W.L. and Beeson, J.P., 2003. Sea-floor sediment distribution in the Gulf of Mexico, Deep-Sea Res. I, 50, 1421–1444.]. The ARM results give an estimate of magnetic grain size distributions, and by analogy, grain size distributions in general, whereas MS patterns show high detrital sediment accumulation zones within the Gulf. The dominant influx of modern high susceptibility sediment into the Gulf of Mexico appears to originate from the Red River, flow into Atchafalaya River Basin and out into the Gulf from Atchafalaya Bay, with significant additional contributions from the Mississippi River through the Southwest Pass of the Mississippi River Delta. This material then moves across the continental shelf and down through the Mississippi Canyon into the deep Gulf where it is redistributed at depths > 3600 m. The eastern shelf margins in the Gulf, offshore from Alabama and Florida, are accumulating calcite- or quartz-rich medium to fine-grained sediment that has a very low or diamagnetic MS signature. From the Louisiana to Texas Gulf coast margins, MS is moderate to high, suggesting a river influx of magnetic constituents from the volcanic fields in New Mexico, and from igneous and metamorphic sources in the Mississippi Basin. Offshore from western Mexico, the MS is high to moderate, but the Yucatan Shelf margin is characterized by low to diamagnetic MS values due to sediment dominated by calcite sands and oozes, a trend that continues to the east onto the West Florida Shelf. Additional measurements of samples collected in association with sites characterized by hydrocarbon seepage exhibit anomalously low MS values. The samples from the lower shelf and slope areas are typified by iron reduction by bacterial organisms in these samples. These results produce anomalous localized lows in the MS trends observed.