自然因素、抽水因素与岩溶塌陷的关系

文章从岩溶发育、土层存在和地下水活动 3个方面论述自然因素、抽水因素在岩溶塌陷的形成过程中所起的作用 ,认为自然因素是决定岩溶塌陷的因素 ,抽水因素是加速岩溶塌陷的因素     

基于微博大数据的北京市流动人口情绪与职住分布的关系研究

流动人口的职住情绪能够反映其工作与生活状态。本研究首先基于2017年北京市微博大数据,利用jieba分词结合人工筛选得到流动人口发布的微博文本;其次,对Roberta-wwm-ext-large模型进行迁移学习识别北京全人群与流动人口的微博情绪;然后,结合POI数据与微博发布时间得到流动人口的职住分布;最后,基于微博情绪与职住分布得到流动人口的职住情绪,利用Getis-Ord Gi*挖掘职住情绪的空间聚集模式,采用地理探测器分析影响职住情绪热点分布的因素。实验表明,北京流动人口情绪均值（0.56）稍低于北京全人群（0.57）（P<0.01）,但整体表现为积极;从空间分布来看,流动人口在东、西城区情绪均衡,西北部科技创新区情绪相对于流动人口情绪均值较为低落,而东南部中心商务区、文化交流区及国际化社区情绪较高涨;从情绪与职住的关系来看,流动人口的工作情绪与从事的工作类型有关（q=0.03,P<0.05）,高新技术产业园、工业园、物流产业园的流动人口从业人员的工作情绪相对于流动人口工作情绪均值较为消极,健康产业园、文化创意产业园、农业园的流动人口从业人员的工作情绪较积极;流动人口的居住情绪与居住环境有关（q=0.06,P<0.1）,居住在远郊区的流动人口情绪相对于流动人口居住情绪均值较为消极,居住在近郊高密度的流动人口情绪较为积极。因此,相关部门应重点关注从事高新技术产业、工业、物流产业的流动人口以及居住在远郊区的流动人口。     

基于Pitzer模型预测Na-K-Ca-Mg-Cl-H2O溶液的密度

天然水体系的体积性质与压力、温度、组成的相关性(PVTx性质)研究在地球化学、盐湖化工等领域有广泛的应用。密度是卤水最基本的体积性质,不仅可以通过实验测定,还可以用理论模型进行预测。建立富钾卤水密度与组成、温度的关联模型有助于认识钾在复杂卤水中的富集、迁移规律。为了构建基于Pitzer离子相互作用模型的卤水密度预测方法,本文用高精度振荡管密度计测定了常压下KCl、CaCl₂纯盐溶液以及最高离子强度为11.8 mol·kg^-1的混合溶液在283~323 K下的密度,用所测得的密度通过Pitzer离子相互作用模型拟合得到多温下Pitzer单电解质参数和Pitzer混合参数。用Pitzer模型参数计算了Na-K-Ca-Mg-Cl-H₂O体系293~313 K的密度,计算密度值与实验值的相对偏差在±0.25%以内,计算的结果整体上要优于文献值,文献在计算中均未考虑Pitzer混合参数项。结果表明,K、Ca、Cl离子间的相互作用对于Na-K-Ca-Mg-Cl-H₂O溶液的密度有显著的影响,本文获得的Pitzer参数反映了这些离子间的相互作用,可用于计算含有K、Ca、Cl离子的复杂卤水密度的预测。     

自然资源要素综合观测体系运维模式及保障体系构建

为实现自然资源要素综合观测体系的长期稳定运行并确保观测数据的科学性和准确性,建立一套适合综合观测体系的运维模式和保障体系意义重大。在分析国内外观测站网运维模式和保障经验的基础上,结合自然资源要素综合观测试点站网的建设、运营情况,提出了领导层+业务执行层+咨询层的运维模式,以及由经费保障、通信网络保障、基建装备保障、数据质量控制保障、野外观测台站日常管理与制度及人才队伍保障构成的自然资源要素综合观测保障体系框架。构建的运维模式层级清晰、职责明确,保障体系框架涵盖面广、重点突出,基本能满足自然资源要素综合观测体系长期、稳定、连续运行和定位观测的运维保障需求。     

长时间尺度下自然资源动态综合区划理论与实践研究——以青藏高原为例

自然资源综合区划是自然资源统一管理与利用的基础,其动态变化是自然资源合理可持续利用的重要科学依据。由于青藏高原海拔高、气候寒冷,分布着除极地以外的最大冰川遗迹,极端的环境和气候对自然资源分布影响较大。选取含冰川积雪在内的14个指标,基于遥感和地理信息系统技术,采用K-means聚类算法对自然资源综合指数进行空间聚类,采用“自上而下”演绎法和“自下而上”归纳法相结合确定研究区自然资源综合区划的等级和范围; 探讨了1990—2018年青藏高原综合区划的变化,分析了自然资源动态变化特征以及空间差异。研究成果清晰地认识了青藏高原的自然资源关系和演化趋势,为区划的多学科交叉应用提供案例。     

河北滦平大兴沟高锶饮用天然矿泉水特征初步评价

河北滦平大兴沟饮用天然矿泉水是一处天然、优质高锶矿泉水,Sr体积质量达2.44 mg/L。通过水文地质测绘、物探、水文地质钻探、水质分析、抽水试验等方法,初步查明了该地区地形地貌、地层岩性、地质构造发育特征以及泉水分布、埋藏、水量、水化学特征等水文地质条件,对该矿泉水特征进行了评价,为下一步矿泉水的勘查提供基础数据。大兴沟饮用天然矿泉水为滦平首次发现的高锶矿泉水,水质稳定,水量大,极具开发利用价值。     

Assessment of the tsunami hazard on the Russian coast based on a new catalogue of tsunamis in the Black Sea and the Sea of Azov

We present the results of work on the compilation of a fuller and more comprehensive historical catalogue of earthquakes and tsunamis in the basin of the Black Sea and the Sea of Azov, an area of primary importance for the Russian Federation. In the 20th century, there were no significant tsunamis in the Black Sea; therefore, its coast was not considered tsunami-prone. A systematic search for new data sources, a revision of earlier ones, and the use of new approaches to the identification of tsunamigenic events resulted in a more than doubling of the number of known tsunamigenic events in this basin, bringing it up to 50. The total length of the new tsunami catalogue reached 3000 years, which makes it the second longest after the Mediterranean tsunami catalogue (about 4000 years). Taking into account the seismotectonic features of the Black Sea region, we processed data on historical tsunamis and analyzed the geographical and temporal distributions of their sources. For all tsunamigenic events we performed a parameterization of available information about their sources and coastal manifestations, evaluated the tsunami intensity based on the Soloviev-Imamura scale, and proposed a classification of tsunami and tsunami-like water wave disturbances based on their genesis. Tsunami run-up heights, inland penetration, and damage were estimated with regard for the newly found data. Among the identified historical events, there are devastating tsunamis with run-ups of 4-5 m, sometimes up to 6-8 m, which resulted in disastrous consequences for several ancient cities (Dioscuria, Sebastopolis, Bizone, and Panticapaeum) and many coastal settlements. Expert assessments of the most tsunami-prone areas of the coasts are given.     

银额盆地哈日凹陷Y井油气地球化学特征与油气源对比

Y井是银额盆地哈日凹陷施钻的第一口揭示二叠系厚度较大的参数钻井,于二叠系试获天然气9.15×104m3/d(无阻流量),并产少量凝析油。在对Y井天然气及凝析油组分、同位素,以及凝析油生物标志化合物等分析的基础上,探讨了天然气和凝析油成因类型。结果表明,天然气为油型(腐泥型)凝析油伴生气,凝析油为高成熟腐泥型,生烃母质以水生生物为主,烃源岩演化进入高成熟阶段。将Y井凝析油与哈日凹陷周缘杭乌拉剖面出露的下二叠统埋汗哈达组烃源岩生物标志化合物特征进行对比,二者具有良好的亲缘关系,Y井凝析油及天然气源于二叠系,进一步证实了银额盆地石炭系—二叠系良好的油气资源前景。     

An alternative approach to determine critical angle of contrast reversal and surface roughness of oil slicks under sunglint

The critical angle is the angle at which the contrast of oil slicks reverse their contrasts against the surrounding oil-free seawater under sunglint. Accurate determination of the critical angle can help estimate surface roughness and refractive index of the oil slicks. Although it’s difficult to determine a certain critical angle, the potential critical angle range help to improve the estimation accuracy. In this study, the angle between the viewing direction and the direction of mirror reflection is used as an indicator for quantifying the critical angle and could be calculated from the solar/viewing geometry from observations of the Moderate Resolution Imaging Spectroradiometer (MODIS). The natural seep oil slicks in the Gulf of Mexico were first delineated using a customized segmentation approach to remove noise and apply a morphological filter. On the basis of the histograms of the brightness values of the delineated oil slicks, the potential range of the critical angle was determined, and then an optimal critical angle between oil slicks and seawater was then determined from statistical and regression analyses in this range. This critical angle corresponds to the best fitting between the modeled and observed surface roughness of seep oil slicks and seawater.     

Analyzing the effect of earthquakes on OpenStreetMap contribution patterns and tweeting activities

ABSTRACT

Natural disasters, such as wildfires, earthquakes, landslides, or floods, lead to an increase in topical information shared on social media and in increased mapping activities in volunteered geographic information (VGI) platforms. Using earthquakes in Nepal and Central Italy as case studies, this research analyzes the effects of natural disasters on short-term (weeks) and longer-term (half year) changes in OpenStreetMap (OSM) mapping behavior and tweet activities in the affected regions. An increase of activities in OSM during the events can be partially attributed to those focused OSM mapping campaigns, for example, through the Humanitarian OSM Team (HOT). Using source tags in OSM change-sets, it was found that only a small portion of external mappers actually travels to the affected regions, whereas the majority of external mappers relies on desktop mapping instead. Furthermore, the study analyzes the spatio-temporal sequence of posted tweets together with keyword filters to identify a subset of users who most likely traveled to the affected regions for support and rescue operations. It also explores where, geographically, earthquake information spreads within social networks.