基于葵花-8卫星宁夏暴雨监测预警指标研究     

张晓茹  李映春  纪晓玲  邵建 《沙漠与绿洲气象(新疆气象)》2022,16(1):41-47

基于葵花-8卫星红外通道资料和地面降水数据,对2017年5—9月宁夏暴雨过程进行云团识别、特征参数(云顶平均亮温、最低亮温、亮温梯度、冷云面积和降温率)计算及监测预警指标分析.结果表明:所选云团特征参数在不同类暴雨过程中有较明显的表现特征.暴雨发生时,云顶平均亮温和最低亮温分别介于213～228 K和199～227 K...  相似文献   

Deep learning-based monitoring of overshooting cloud tops from geostationary satellite data     

Miae Kim  Junghye Lee 《地理信息系统科学与遥感》2018,55(5):763-792

Overshooting tops can cause a variety of severe weather conditions, such as cloud-to-ground lightning, strong winds, and heavy rainfall, which can affect flight and ground operations. Many previous studies have developed overshooting top (OT) detection models. However, rather than identifying individual pixels in satellite images as OTs or non-OTs, we typically find OTs through visual inspection of the contextual information of pixels (i.e., dome-like shape). Such an approach is more intuitive, accurate, and generalizable regardless of the OT characteristics that are used in the existing OT detection algorithms. In this paper, a new approach is proposed for OT detection using deep learning, more specifically a convolutional neural network (CNN), which can mimic the human process by convolution operation. Himawari-8 satellite images were used as input data, which were chopped into patches (i.e., grids) with a 31 × 31 window size and binary detection (OT or non-OT) for each patch was the output of the model. The validation results show that CNN can be successfully applied for the detection of OTs over the tropical regions, showing a mean probability of detection (POD) of 79.68% and a mean false alarm ratio (FAR) of 9.78%.  相似文献   

鄂尔多斯盆地合水地区长8₁亚油层组沉积相及对储层物性的影响          下载免费PDF全文

王茜  魏凡  张妍  范琳  方一钢 《沉积与特提斯地质》2021,41(1):88-99

为研究鄂尔多斯盆地上三叠统延长组长81亚油层组沉积微相与储层物性的关系,通过岩心相、测井相及物性等资料,结合前人研究成果,对盆内合水地区长8₁亚油层组进行分析。认为:(1)长8₁亚油层组浅水三角洲前缘沉积发育水下分流河道、河口坝、前缘席状砂、分流间湾4种沉积微相。多期叠置的水下分流河道是控制砂体发育的主要微相类型,根据砂地比又可分为河道核部、河道中部及河道侧翼;(2)长8₁²小层水下分流河道砂体发育频率较高、沉积期次较多、连通性较强,其次为长88₁²小层与长8₁³小层;(3)由沉积微相决定的岩石结构成熟度控制了储层的初始孔隙度,进而在一定程度上影响了储层现今孔隙度。水下分流河道核部储层物性最好,是有利微相类型。研究区长8₁²小层有利微相发育规模最大,为后期勘探开发首要目的层位。  相似文献   

吴起薛岔地区长8油层组储层岩石学特征研究     

黄天坤  郑庆华 《地下水》2018,(6):131-132,140

吴起薛岔地区是近年来延长油田的潜力目标开发区,其长8油层组油藏分布面积和储量潜力大。因此,本文通过钻井岩心、铸体薄片、扫描电镜观察和粒度、X衍射全岩分析、黏土矿物定量分析,对研究区长8油层组储层岩石学特征进行了研究。结果显示,研究区长8油层组岩性主要由灰褐色细粒岩屑长石砂岩组成,长石砂岩次之,具有"低石,高长石"特点;碎屑颗粒多为次棱角状,分选性中等,胶结类型以孔隙及加大孔隙型为主;填隙物含量均大于15%,主要以绿泥石膜、水云母、方解石以及铁方解石等自生矿物为主,以及少量高岭石和网状粘土等。  相似文献   

Seismic microzonation of Chania,Crete (Greece) based on SASW measurements and non-linear site response analyses     

《Soil Dynamics and Earthquake Engineering》2013

Following a brief overview of past applications of, and more recent advances on seismic microzonation, the results of a seismic microzonation study for the city of Chania, Greece, are presented. The study was based on V_s vs. depth profiles obtained at 19 sites of the urban area by performing SASW measurements. The spatial distribution of V_s values was utilized in estimating V_s30 values, depth to bedrock and the fundamental ground period variation across the area of the city as well as for conducting 1-D finite element non-linear inelastic site response analyses. The input earthquake excitations employed in the response analyses were based on the results of an available seismic hazard study for the Chania Area. The results of analyses were utilized for establishing the spatial distribution of rock motion amplification, the expected ground motions and spectral values in the area of the city. Contour maps providing values of the expected ground motion in the urban area are given which may become a practical tool in assessing the seismic risk and expected damage in the Chania area. The maps can also be used in the design of new earthquake resistant structures or the seismic retrofitting of existing ones. Finally, the results were utilized to demonstrate the inadequacy of using V_s,30 values for classifying the soil conditions in the Chania area.  相似文献   

熵权法储层非均质定量评价方法研究——以鄂尔多斯盆地下寺湾长8储层为例          下载免费PDF全文

杨争光  汤军  张云鹏 《江苏地质》2012,36(4):373-378

在相控约束条件下,利用熵权方法,考虑了砂层厚度、有效厚度、砂岩系数、有效厚度系数、分层系数、夹层频数、夹层分布密度、孔隙度、渗透率、渗透率变异系数、突进系数、级差、含油饱和度共13种反映储层非均质性的参数,定量计算储层非均质综合指数。该方法包括确定对象集合、指标因素集合、指标矩阵、归一化指标值、指标权重和计算综合指数等。熵权非均质综合指数算法可将数值有差异的属性参数对非均质指数的贡献进行弱化和强化,即去同存异;熵权非均质综合指数的大小能定量表征储层的非均质性。利用该方法在下寺湾油田柳洛峪区长8储层进行了应用,定量地刻画了储层的平面非均质性,取得了满意的效果。  相似文献   

内蒙古西部额济纳旗祥探8井华力西期风化壳 原油地球化学特征   总被引：1，自引：0，他引：1  

曹洁  魏仙样  严小鳙  李玉宏  魏建设 《地质通报》2012,31(10):1639-1644

根据对祥探8井华力西末期风化壳原油地球化学特征的分析,原油具有饱和烃含量高,芳烃、非烃、沥青质含量低和全油C同位素轻的特点,生物标志化合物藿烷系列具有C30藿烷含量高,伽马蜡烷含量相对较高等特点,指示生烃母质类型好,沉积环境为高含盐的还原环境,烃源岩演化程度较高。与祥探9井烃源岩生物标志化合物特征一致,指示与石炭系烃源岩具有良好的亲缘关系。  相似文献   

华北克拉通南缘洛峪群-汝阳群属于中元古界长城系——河南汝州洛峪口组层凝灰岩锆石LA—MC-ICPMSU—Pb年龄的直接约束   总被引：17，自引：0，他引：17  

苏文博  李怀坤  徐莉  贾松海  耿建珍  周红英  王志宏  蒲含勇 《华北地质》2012,35(2):96-108

运用LA—MC—ICPMS方法,对河南汝州阳坡村附近洛峪口组中部层凝灰岩夹层开展了锆石U-Pb同位素年代学研究,获得了1611±8Ma的高精度年龄。这一年龄第一次精确标定了该地区洛峪口组的形成时限,并显示该组顶界应接近1600Ma。由于洛峪口组位于华北克拉通南缘原划归“新元古界青白口系”洛峪群的最顶部,洛峪群又覆于“中元古界蓟县系”汝阳群之上,因此,这一新的年代学进展实际上同时也将洛峪群和汝阳群都下压到了中元古界长城系,并将洛峪群顶界限定为该地区长城系与蓟县系分界。结合区域资料,特别是熊耳群（下伏于汝阳群）火山岩近年来的年代学标定（多集中于1750～1780Ma）,可初步将该地区汝阳群一洛峪群的形成年代限定为1750～1600Ma之间,对应于国际固结纪（Statherian。1800～1600Ma）即中国长城纪中晚期。华北南缘洛峪口组形成年龄的直接约束及相关地层划分的重新厘定,为中元古代华北克拉通南北缘的准确对比及其与哥伦比亚超大陆关系、早期生命演化等重大地学命题提供了新的重要的年代学证据。  相似文献   

Towards a Higher Comparability of Geothermometric Data obtained by Raman Spectroscopy of Carbonaceous Material. Part I: Evaluation of Biasing Factors   总被引：1，自引：0，他引：1  

Nils K. Lünsdorf  Istvan Dunkl  Burkhard C. Schmidt  Gerd Rantitsch  Hilmar von Eynatten 《Geostandards and Geoanalytical Research》2014,38(1):73-94

Raman spectroscopy of carbonaceous material (RSCM) is frequently used to determine metamorphic peak temperatures from the structural order of carbonaceous material enclosed in metasediments. This method provides a quick, robust and relatively cheap geothermometer. However, the comparability of the RSCM parameter is low as there are at least three major sources of biasing factors. These sources are the spectral curve‐fitting procedure, the sample characteristics itself and the experimental design including the used Raman system. To assess the impacts of the biasing factors on RSCM, a series of experiments was performed. The experiments showed that curve‐fitting is strongly influenced by individual operator‐bias and the degrees of freedom in the model, implying the need for a standardised curve‐fitting procedure. Due to the diversity of components (optics, light detection device, gratings, etc.) and their combinations within the Raman systems, different Raman instruments generally give differing results. Consequently, to estimate comparable metamorphic temperatures from RSCM data, every Raman instrument needs its own calibration. This demands a reference material series that covers the entire temperature calibration range. Although sample heterogeneity will still induce some variation, a reference material series combined with standardised curve‐fitting procedures will significantly increase the overall comparability of RSCM data from different laboratories.  相似文献   

黑土型退化草地时空格局遥感监测     

刘云峰  秦坤  吕慧玲  陈思宇 《测绘通报》2022,(11):57-61

准确及时地了解黑土型退化草地的时空分布特点,对祁连山地区草地退化修复治理具有重要意义。本文选取祁连县野牛沟乡西北部区域作为研究区,基于Landsat 8 OLI影像,结合地理国情监测成果,尝试利用分场景的决策树分类方法提取黑土型退化草地范围,并对比分析2014-2019年黑土型退化草地的时空变化特征。结果表明,多场景的决策树分类方法对黑土型退化草地监测具有很好的适用性;2014-2019年,研究区北部部分区域缓坡地和中部滩地黑土型退化问题有所好转,西部和西北部缓坡地黑土型退化问题有进一步恶化的趋势;好转草地主要以人工干预为主,恶化草地可能是受水热空洞效应、鼠害等多种因素的影响。  相似文献