面向未来课堂的网络GIS本科课程改革研究     

郭明强  谢忠  吴亮  黄颖 《测绘工程》2016,25(10):76-80

随着网络GIS课程知识结构的不断发展,社会人才需求呈现出多样性,传统的网络GIS本科课程难以应对培养目标的动态性和学习者之间的差异性,使得网络GIS专业本科教学面临巨大的挑战。分析网络GIS课程改革的新需求,综合考虑网络GIS课程和学习者的特点,借鉴"未来课堂"教学理念,提出顾及学习者学习新特点的网络GIS"未来课堂"教学设计。促使网络GIS"未来课堂"能够顾及全体学习者的性格特征和兴趣,充分调动学习者的积极性,最终实现教与学有机统一的网络GIS"未来课堂"。  相似文献   

西藏古堆地区基于DPIS的成矿远景区的圈定     

陈武  胡可卫  陈东太  黄锦彦 《矿产与地质》2016,(2):245-250

西藏古堆地区地处特提斯―喜马拉雅构造域一级构造单元之喜马拉雅片的中段,北涉雅鲁藏布江板块结合带。区内成矿条件较好,本文在前人成果资料的基础上,利用"矿床位置预测系统(DPIS)"中的信息量计算法,筛选了六大类38个标志信息进行信息量计算,圈出了信息总量异常区,再通过地质资料的综合分析,进行成矿远景区的圈定,取得了较好的效果。  相似文献   

山东焦家构造南延特征及成矿分析     

苏旭亮  赵闯  谢永健 《江苏地质》2016,40(4):599-603

焦家构造是胶东重要的控矿构造,为一压扭和张扭性复合大型伸展构造,因其赋存有众多大型、特大型金矿而倍受关注,南延至朱桥以南被第四系广泛覆盖,南延问题是一个研究热点,目前并没有明确的定位。根据近年在莱州平里店一带的地质工作情况分析认为,焦家构造有南延,分布在平里店一带隐伏古元古界地层中而呈分散状态,主要因变质岩地层结构疏松、离岩体较远、构造容易变形分散造成,南段和北段构造特征有差异。此外,南延在缺少岩体侵入的情况下,缺少岩浆热液活动,地层中的Au元素难以富集,也是其南延不易形成大型金矿的主要原因。  相似文献   

基于证据加权模型的综合信息成矿预测     

杨佳佳  林楠 《地质学报》2016,90(10):2908-2918

综合信息成矿预测是复杂高维非线性系统的建模与评价过程,通过识别和提取地、物、化、遥等多源地学观测数据中的综合致矿地质异常信息,并以此为依据进行成矿预测。成矿预测是在科学预测理论的指导下,应用地质成矿理论和数理统计方法对地质、物探、化探、遥感等信息进行充分挖掘,剖析成矿地质条件,总结成矿规律,建立综合信息成矿模型并应用于成矿预测,从而圈定和评价成矿远景区,为区域找矿工作部署和矿产资源开发利用的统筹规划提供科学依据。本次研究将证据加权模型引入到成矿预测研究中,通过建立和评价地质信息、化探信息、遥感蚀变信息、遥感线环形构造密度信息与已知矿化点的关系,然后用贝叶斯公式计算成矿后验概率,推出研究区成矿预测结果。研究结果表明:综合信息成矿模型预测结果符合研究区地质成矿规律,和已知成矿点吻合率达71.4%。  相似文献   

青海祁漫塔格中段铀成矿要素分析与远景预测     

潘蔚  余长发  田青林  戴佳文  王树红  尹力 《铀矿地质》2016,(3):146-151

发现于青海祁漫塔格中段的黑山铀矿点被认为是硅化带复成因类型,但近年来又被当作花岗岩外带型铀矿进行勘探与评价。笔者在野外观察发现,该矿点的1号矿带产于地表浅部、矿化岩石主要为碎裂片岩、片麻岩,围岩蚀变以褐铁矿化为主。室内研究表明,铀主要以分散吸附和次生铀矿物形式存在。2号带矿化位于地下,矿化部位与潜水面深度相当,且矿化岩石无明显的铀矿物和热液蚀变。遥感解译发现,黑山地区铀矿化受一条南北向断裂构造控制。经野外验证,该构造为一张性断裂,在祁漫塔格主脊断裂以北呈河谷地貌,控制河流走向;主脊断裂以南成垭口或陡崖地貌,分别控制铀矿点的1、2号带。笔者认为,黑山铀矿点是浅表地下水沿断裂破碎带对富铀岩层改造作用的结果。基于这种认识,对祁漫塔格中段进一步开展了多尺度遥感解译和蚀变信息提取;对新发现的南北向构造与蚀变异常分布区,利用铀矿地质和水系沉积物地球化学等信息进行了重点研究,划出4片成矿远景预测区。经野外查证,在黑山南部预测区发现了构造糜棱岩型铀矿化异常点;在西大沟预测区找到了硅化带型铀异常。  相似文献   

塞拉利昂中部马卡利地区金矿特征及成矿远景          下载免费PDF全文

张予祥 《地质找矿论丛》2016,31(2):282-288

塞拉利昂中部马卡利地区出露有大片的太古界花岗-绿岩带地质体,其金矿资源丰富。通过矿产勘查和成矿规律研究表明,金的来源与太古界花岗-绿岩带地体密切相关。岩金矿床类型为含铁建造金矿床,主要赋存于绿岩带的绿片岩中及含铁建造的片岩中,受褶皱和断裂构造控制;砂金矿的类型为河流冲积型砂金矿,主要分布在花岗-绿岩带内及其周边河流中的全新统冲积层中下部砂砾石层中。重砂异常和地球化学异常区内具备良好的岩金、砂金成矿地质背景和找矿前景,实施砂金-岩金综合找矿方法,找矿潜力巨大。  相似文献   

How Frequently Will the Persistent Heavy Rainfall over the Middle and Lower Yangtze River Basin in Summer 2020 Happen under Global Warming?     

Zi-An GE  Lin CHEN  Tim LI  Lu WANG 《大气科学进展》2022,39(10):1673-1692

The middle and lower Yangtze River basin (MLYRB) suffered persistent heavy rainfall in summer 2020, with nearly continuous rainfall for about six consecutive weeks. How the likelihood of persistent heavy rainfall resembling that which occurred over the MLYRB in summer 2020 (hereafter 2020PHR-like event) would change under global warming is investigated. An index that reflects maximum accumulated precipitation during a consecutive five-week period in summer (Rx35day) is introduced. This accumulated precipitation index in summer 2020 is 60% stronger than the climatology, and a statistical analysis further shows that the 2020 event is a 1-in-70-year event. The model projection results derived from the 50-member ensemble of CanESM2 and the multimodel ensemble (MME) of the CMIP5 and CMIP6 models show that the occurrence probability of the 2020PHR-like event will dramatically increase under global warming. Based on the Kolmogorov–Smirnoff test, one-third of the CMIP5 and CMIP6 models that have reasonable performance in reproducing the 2020PHR-like event in their historical simulations are selected for the future projection study. The CMIP5 and CMIP6 MME results show that the occurrence probability of the 2020PHR-like event under the present-day climate will be double under lower-emission scenarios (CMIP5 RCP4.5, CMIP6 SSP1-2.6, and SSP2-4.5) and 3–5 times greater under higher-emission scenarios (3.0 times for CMIP5 RCP8.5, 2.9 times for CMIP6 SSP3-7.0, and 4.8 times for CMIP6 SSP5-8.5). The inter-model spread of the probability change is small, lending confidence to the projection results. The results provide a scientific reference for mitigation of and adaptation to future climate change.  相似文献   

The anticipatory governance of sustainability transformations: Hybrid approaches and dominant perspectives     

《Global Environmental Change》2022

Anticipation methods and tools are increasingly used to try to imagine and govern transformations towards more sustainable futures across different policy domains and sectors. But there is a lack of research into the steering effects of anticipation on present-day governance choices, especially in the face of urgently needed sustainability transformations. This paper seeks to understand how different perspectives on anticipatory governance connect to attempts to guide policy and action toward transformative change. We analyze perspectives on anticipatory governance in a global network of food system foresight practitioners (Foresight4Food) – using a workshop, interviews, and a survey as our sources of data. We connect frameworks on anticipatory governance and on transformation to analyse different perspectives on the future and their implications for actions in the present to transform food systems and offer new insights for theory and practice. In the global Foresight4Food network, we find that most foresight practitioners use hybrid approaches to anticipatory governance that combine fundamentally different assumptions about the future. We also find that despite these diverse food futures, anticipation processes predominantly produce recommendations that follow more prediction-oriented forms of strategic planning in order to mitigate future risks. We further demonstrate that much anticipation for transformation uses the language on deep uncertainty and deliberative action without fully taking its consequences on board. Thus, opportunities for transforming future food systems are missed due to these implicit assumptions that dominate the anticipatory governance of food systems. Our combined framework helps researchers and practitioners to be more reflexive of how assumptions about key human systems such as food system futures shape what is prioritized/marginalized and included/excluded in actions to transform such systems.  相似文献   

青海省浪琴地区成矿条件与找矿前景分析          下载免费PDF全文

罗小平 《中国地质调查》2018,5(3):17-26

青海省天峻县浪琴地区1∶5万区域地质矿产调查,综合利用已有区域地质、物探、化探、遥感及矿产等资料,在区域地质调查、水系沉积物测量和遥感解译及蚀变信息提取等基础上,开展矿点概略性检查和物化探异常查证等工作,基本查明了区内铜、金、银、钒、铬、镍等矿产的成矿地质背景和成矿条件,圈定了45处水系沉积物单元素异常,其中乙类异常31处,丙类异常14处,新发现金属矿(化)点4处,圈定了找矿远景区,指明了找矿方向。  相似文献   

岩浆热液型银矿床、银矿省及形成的控制因素     

回凯旋  秦克章  韩日  赵俊兴  王乐  高燊  张夏楠 《岩石学报》2021,37(8):2502-2520

岩浆热液型银矿床主要指与岩浆热液作用相关的独立银矿床和共生银矿床(Ag平均品位一般大于100g/t),它是银最重要的来源。本文对全球80多个典型的大型-超大型岩浆热液型银矿床进行了梳理和总结,将其主要分为浅成低温热液型(低硫型、中硫型和高硫型)、矽卡岩型、斑岩型和五元素型四种类型,其中浅成低温热液型占主导,斑岩型和矽卡型数量较少。全球大型-超大型的岩浆热液型银矿床主要分布在东太平洋俯冲带和中亚造山带东段,这些银矿床均位于陆壳基底之上。按照发育地区不同可分为六大银成矿省,即中国兴蒙银成矿省、美国西部盆岭银成矿省、墨西哥西北银成矿省、秘鲁中部银多金属成矿省、玻利维亚银锡成矿省和俄罗斯远东银锡成矿省。成矿时代主要集中在中、新生代。这些银成矿省与大规模酸性-中酸性岩浆活动密切相关,包括发育大量酸性熔结凝灰岩的长英质大火成岩省,或者富锡流纹岩、黄玉流纹岩和石英斑岩等高演化岩浆岩。这些大规模岩浆热液银成矿作用通常与区域大地构造背景转换相关,比如从挤压到伸展或者伸展到挤压。相对富银的含水大陆下地壳源区、大规模高分异的岩浆作用、银对熔体中共存硫化物和磁铁矿相对弱的相容性、高盐度的流体、成矿流体集中运移的通道和高效的沉淀机制是银大规模成矿的有利控制因素。银矿床的研究工作相对于铜、金矿床远远落后,银成矿省和酸性大火成岩省的内在联系、控制斑岩钼-银/锡-银两种银成矿系统的机制、岩浆演化对银成矿的控制、银矿潜力区的勘查找矿等关键问题仍亟待解决。  相似文献