GlobeLand30: Operational global land cover mapping and big-data analysis

正Information regarding Land cover and change (LCC) over time is essential for a variety of Societal Benefits Areas(SBA), such as environmental change analysis, geographical condition monitoring, urban and rural management, earth surface process modeling, and sustainable development.Since the middle of 1990s, the international scientific communities have devoted tremendous efforts to Global Land Cover (GLC) mapping, and developed a number of coarser resolution (ranging from 300-m to 1 km) data products. As     

The Antarctic meteorite Yamato 74123 — a new ureilite

The rare gases He, Ne, Ar, Kr and Xe were measured in bulk samples of Yamato 74123. The ³He and ²¹Ne exposure ages are found to be 5.50 Ma and 2.83 Ma, respectively. In addition to the cosmogenic component the samples contain primordial rare gases of the fractionated type in amounts typical of ureilites. In a three-isotope plot neon turns out to be a mixture of planetary neon and cosmogenic neon.The elements Na, Mg, Al, Si, P, S, K, Ca, Cr, Mn, Fe, Co, and Ni have been determined by spark source mass spectrometry in Yamato 74123 and for comparison in the ureilites Haveröand Kenna. The chemical composition as well as the noble gas abundance pattern identify Yamato 74123 as an ureilite.     

Patch scale aggregation of heterogeneous land surface cover for mesoscale meteorological models

Theoretical studies dealing with aggregation of surface parameters at small scale are reviewed. Finding effective parameters for surface resistance is possible for most cases by taking simple geometric or arithmetic averages of the component resistances. The use of more sophisticated techniques such as the blending height improves the calculations. Resistances for heat and water vapour behave differently in heterogeneous terrain. A simple surface energy balance model is adapted to show the behaviour of the roughness length of heat and water vapour in heterogeneous terrain. It is suggested that this simple parameterization can adequately take into account the effect of variation in surface cover on the fluxes of heat and water vapour.     

Novel fuzzy uncertainty modeling for land cover classification based on clustering analysis

It is well known that there is a degree of fuzzy uncertainty in land cover classification using remote sensing (RS) images. In this article, we propose a novel fuzzy uncertainty modeling algorithm for representing the features of land cover patterns, and present an adaptive interval type-2 fuzzy clustering method. The proposed fuzzy uncertainty modeling method is performed in two main phases. First, the segmentation units of the input multi-spectral RS image data are subjected to objectbased interval-valued symbolic modeling. As a result, features for each land cover type are represented in the form of an intervalvalued symbolic vector, which describes the intra-class uncertainty better than the source data and improves the separability between different classes. Second, interval type-2 fuzzy sets are generated for each cluster based on the distance metric of the interval-valued vectors. This step characterizes the inter-class high-order fuzzy uncertainty and improves the classification accuracy. To demonstrate the advantages and effectiveness of the proposed approach, extensive experiments are conducted on two multispectral RS image datasets from regions with complex land cover characteristics, and the results are compared with those given by well-known fuzzy and conventional clustering algorithms.     

Continuous land cover change monitoring in the remote sensing big data era

<正>Since the late 20th century,global change issues have attracted lots of attention.As a key component of global changes,land cover and land use information has been increasingly important for improved understanding of global environmental changes and feedbacks between social and environmental systems(Verburg et al.,2015).A set of national and global scale land cover/use products with higher spatial and temporal resolutions have been developed to fill this gap.In China,existing efforts include China’s National     

An EcoCity model for regulating urban land cover structure and thermal environment: Taking Beijing as an example

Urban land-use/cover changes and their effects on the eco-environment have long been an active research topic in the urbanization field. However, the characteristics of urban inner spatial heterogeneity and its quantitative relationship with thermal environment are still poorly understood, resulting in ineffective application in urban ecological planning and management.Through the integration of "spatial structure theory" in urban geography and "surface energy balance" in urban climatology, we proposed a new concept of urban surface structure and thermal environment regulation to reveal the mechanism between urban spatial structure and surface thermal environment. We developed the EcoCity model for regulating urban land cover structure and thermal environment, and established the eco-regulation thresholds of urban surface thermal environments. Based on the comprehensive analysis of experimental observation, remotely sensed and meteorological data, we examined the spatial patterns of urban habitation, industrial, infrastructure service, and ecological spaces. We examined the impacts of internal land-cover components(e.g., urban impervious surfaces, greenness, and water) on surface radiation and heat flux. This research indicated that difference of thermal environments among urban functional areas is closely related to the proportions of the land-cover components.The highly dense impervious surface areas in commercial and residential zones significantly increased land surface temperature through increasing sensible heat flux, while greenness and water decrease land surface temperature through increasing latent heat flux. We also found that different functional zones due to various proportions of green spaces have various heat dissipation roles and ecological thresholds. Urban greening projects in highly dense impervious surfaces areas such as commercial, transportation, and residential zones are especially effective in promoting latent heat dissipation efficiency of vegetation, leading to strongly cooling effect of unit vegetation coverage. This research indicates that the EcoCity model provides the fundamentals to understand the coupled mechanism between urban land use structure and surface flux and the analysis of their spatiotemporal characteristics. This model provides a general computational model system for defining urban heat island mitigation, the greening ratio indexes, and their regulating thresholds for different functional zones.     

世界应力图2000版( WSM2000)介绍及使用说明

全球地壳应力状态对于地学及相关领域科学研究意义重大,因此测量全球地壳应力并绘制全球地壳应力图一直受到国际地学界广泛关注．1986年开始实施的世界应力图计划(WSMP：World Stress Map Project,以下简称WSM)经各国专家多年合作和努力工作,现已出版了最新WSM2000版本应力数据库．该数据库在WSMl997版基础上新增收录了4216个观测数据,使其总共包含了全球10920个可靠应力测量数据,并绘制了全球应力图和部分地区的局部应力图,为地质地球物理研究提供了准确详细的应力数据．本文结合WSM官方网站的资料从数据库结构、数据来源、数据质量、数据摘要描述等方面介绍WSM2000数据库,以使国内研究迅速利用此宝贵的数据资源.     

Modelling the water balance of a mesoscale catchment basin using remotely sensed land cover data

Hydrological modelling of mesoscale catchments is often adversely affected by a lack of adequate information about specific site conditions. In particular, digital land cover data are available from data sets which were acquired on a European or a national scale. These data sets do not only exhibit a restricted spatial resolution but also a differentiation of crops and impervious areas which is not appropriate to the needs of mesoscale hydrological models. In this paper, the impact of remote sensing data on the reliability of a water balance model is investigated and compared to model results determined on the basis of CORINE (Coordination of Information on the Environment) Land Cover as a reference. The aim is to quantify the improved model performance achieved by an enhanced land cover representation and corresponding model modifications. Making use of medium resolution satellite imagery from SPOT, LANDSAT ETM+ and ASTER, detailed information on land cover, especially agricultural crops and impervious surfaces, was extracted over a 5-year period (2000–2004). Crop-specific evapotranspiration coefficients were derived by using remote sensing data to replace grass reference evapotranspiration necessitated by the use of CORINE land cover for rural areas. For regions classified as settlement or industrial areas, degrees of imperviousness were derived. The data were incorporated into the hydrological model GROWA (large-scale water balance model), which uses an empirical approach combining distributed meteorological data with distributed site parameters to calculate the annual runoff components. Using satellite imagery in combination with runoff data from gauging stations for the years 2000–2004, the actual evapotranspiration calculation in GROWA was methodologically extended by including empirical crop coefficients for actual evapotranspiration calculations. While GROWA originally treated agricultural areas as homogeneous, now a consideration and differentiation of the main crops is possible. The accuracy was determined by runoff measurements from gauging stations. Differences in water balances resulting from the use of remote sensing data as opposed to CORINE were analysed in this study using a representative subcatchment. Resulting Nash–Sutcliff model efficiencies improved from 0.372 to 0.775 and indicate that the enhanced model can produce thematically more accurate and spatially more detailed local water balances. However, the proposed model enhancements by satellite imagery have not exhausted the full potential of water balance modelling, for which a higher temporal resolution is required.     

Climate effects of the GlobeLand30 land cover dataset on the Beijing Climate Center climate model simulations

Land cover is one of the most basic input elements of land surface and climate models. Currently, the direct and indirect effects of land cover data on climate and climate change are receiving increasing attentions. In this study, a high resolution (30 m) global land cover dataset (GlobeLand30) produced by Chinese scientists was, for the first time, used in the Beijing Climate Center Climate System Model (BCC_CSM) to assess the influences of land cover dataset on land surface and climate simulations. A two-step strategy was designed to use the GlobeLand30 data in the model. First, the GlobeLand30 data were merged with other satellite remote sensing and climate datasets to regenerate plant functional type (PFT) data fitted for the BCC_CSM. Second, the up-scaling based on an area-weighted approach was used to aggregate the fine-resolution GlobeLand30 land cover type and area percentage with the coarser model grid resolutions globally. The GlobeLand30-based and the BCC_CSM-based land cover data had generally consistent spatial distribution features, but there were some differences between them. The simulation results of the different land cover type dataset change experiments showed that effects of the new PFT data were larger than those of the new glaciers and water bodies (lakes and wetlands). The maximum value was attained when dataset of all land cover types were changed. The positive bias of precipitation in the mid-high latitude of the northern hemisphere and the negative bias in the Amazon, as well as the negative bias of air temperature in part of the southern hemisphere, were reduced when the GlobeLand30-based data were used in the BCC_CSM atmosphere model. The results suggest that the GlobeLand30 data are suitable for use in the BCC_CSM component models and can improve the performance of the land and atmosphere simulations.     

NNR constraint in ITRF2000 and the new global plate motion model NNR-ITRF2000VEL

There are 54 sites employed by ITRF2000 for ITRF2000 orientation. The deficiencies are obvious. First, these sites cannot well represent the rotation rate of the earth crust because there is no selected site in five out of fourteen tectonic plates and three of fourteen plates only have one site each. Second, the total angular momentum of the crust is non-vanishing in ITRF2000, even though it is declared that No Net Rotation (NNR) with respect to NNR-NUVEL1A is imposed on ITRF2000 construction according to the documentations of ITRF2000. So the NNR condition in conventional terrestrial reference system (CTRS) realization cannot be satisfied in ITRF2000. In this paper, the criteria of site selection for estimating the Euler vectors are suggested; the Tisserand system constraint equation in ITRF construction is derived; and as a product, the global plate motions can be obtained from the ITRF2000 construction.     

Assessment of visual interpretation of thematic mapper (TM) images for land use and cover in Sudan

Three thematic mapper (TM) images, a band 3 image, a band 4 image and a 432 colour composite image of Khartoum were compared for detection, identification and recognition of land use and cover classes in hydrology in Sudan. Simple visual interpretational techniques were employed for this purpose. The results show that visual interpretation procedures can be very useful for an inventory of hydrologic land use and cover using Landsat TM photographic products. This is an important conclusion for developing countries where digital techniques are very expensive at the present and many developing countries cannot afford to make use of them.     

Assessing the impacts of land cover and climate on runoff and sediment yield of a river basin

ABSTRACT

This study investigated the impacts of changes in land cover and climate on runoff and sediment yield in a river basin in India. Land Change Modeler was used to derive the future land cover and its changes using the Sankey diagram approach. The future climatic parameters were derived from five general circulation models for two emission scenarios with representative concentration pathways (RCPs) 4.5 and 8.5. The land cover and climate change impacts on runoff and sediment yield were estimated using SWAT model. The results show important changes in land cover and indicate that urban and agricultural areas strongly influence the runoff and sediment yield. Among the land cover and climate change impacts, climate has more predominant (70%–95%) impact. Runoff and sediment yield are likely to decrease in both RCP scenarios in the future period. The impacts of land cover changes are more prominent on sediment yield than runoff.     

基于气象色谱仪产出数据的数据库设计

为了更好的管理BF-2002色谱工作站从气象色谱仪SP3400采集的数据,设计了气象色谱仪数据库,实现了对色谱仪产出的原始数据,谱图数据及气样分析结果等数据的统一管理,方便了观测数据的使用和分析研究。本文就数据库设计及创建过程中所应用的技术进行了简要阐述。     

An operating philosophy for the US Antarctic program

In the early days of Antarctica's exploration, there was scant consideration among expeditioners of human impact on its environment. Today, several national programmes of research in Antarctica have become regular undertakings. The time of the antarctic explorer and adventurer, where rules and sanctions were scant, is past. With their on-site laboratories; arrangements for accommodation; fleets of aircraft, ships, and land vehicles; and requirements for materials influx and removal, these programmes possess the characteristics of ‘big science’. As such they cannot, and do not, conduct their business as in the past. They require an overarching philosophy to guarantee compatibility with Antarctica's unique environment so as to ensure its value to future scientific investigation.     

Accuracy assessments and uncertainty analysis of spatially explicit modeling for land use/cover change and urbanization:A case in Beijing metropolitan area

Spatially explicit modeling plays a vital role in land use/cover change and urbanization research as well as resources management;however,current models lack proper validation and fail to incorporate uncertainty into the formulation of model predictions.Consequently,policy makers and the general public may develop opinions based on potentially misleading research,which fails to allow for truly informed decisions.Here we use an uncertainty strategy of spatially explicit modeling combined with the series stat...     

Snow cover data management: the role of WDC-A for Glaciology

ABSTRACT

Up to now the study of snow cover conditions has been carried out on a local or regional scale. Research is hindered because the data are not even homogeneous in different countries. As a contribution to the assembly of such data, WDC-A for Glaciology has initiated an inventory of the observational methods and variables measured. Further, a Cryospheric Data Management System is being developed which will enable snow cover maps to be constructed, for example, using passive microwave data from the US DMSP satellite.     

The recently compiled Turkish strong motion database: preliminary investigation for seismological parameters

Strong motion data recorded by the Turkish national strong motion network has been compiled and processed systematically for the first time, together with detailed geophysical and geotechnical site measurements for all of its stations. The catalog information of 18 seismological agencies and other sources were examined to obtain reliable source, geometry, and distance parameters for each event. The high quality digital and analog strong motion data was processed by a uniform methodology to remove the high- and low-frequency noise. Currently, the seismological and spectral information of 4,607 strong motion records are available for use by earth scientists and earthquake engineers. In this article, we present the fundamental features of this database and explain our methodology in their calculation. We present several comparisons of our database with other related studies to verify our approach during the computational stage of the seismological parameters. The results confirm the reliability of our calculations. The database has also enabled us to derive empirical magnitude conversion relationships to estimate moment magnitude in terms of different magnitude scales. The article ends with a discussion of the likely improvements in the European accelerometric data through contributions from this strong motion database applicable for seismically active shallow-crust regions. The findings of this article emphasize the necessity of global strong motion databases in Europe for better estimation of seismic hazard in regions of similar seismotectonic environment.