APPLICATION OF DEM GENERATION TECHNOLOGY FROM HIGH RESOLUTION SATELLITE IMAGE IN QUANTITATIVE ACTIVE TECTONICS STUDY: A CASE STUDY OF FAULT SCARPS IN THE SOUTHERN MARGIN OF KUMISHI BASIN

Traditional method to generate Digital Elevation Model (DEM)through topographic map and topographic measurement has weak points such as low efficiency, long operating time and small range. The emergence of DEM-generation technology from high resolution satellite image provides a new method for rapid acquisition of large terrain and geomorphic data, which greatly improves the efficiency of data acquisition. This method costs lower compared with LiDAR (Light Detection and Ranging), has large coverage compared with SfM (Structure from Motion). However, there is still lack of report on whether the accuracy of DEM generated from stereo-imagery satisfies the quantitative research of active tectonics. This research is based on LPS (Leica Photogrammetry Suit)software platform, using Worldview-2 panchromatic stereo-imagery as data source, selecting Kumishi Basin in eastern Tianshan Mountains with little vegetation as study area. We generated 0.5m resolution DEM of 5-km swath along the newly discovered rupture zone at the south of Kumishi Basin, measured the height of fault scarps on different levels of alluvial fans based on the DEM, then compared with the scarp height measured by differential GPS survey in the field to analyze the accuracy of the extracted DEM. The results show that the elevation difference between the topographic profiles derived from the extracted DEM and surveyed by differential GPS ranges from -2.82 to 4.87m. The shape of the fault scarp can be finely depicted and the deviation is 0.30m after elevation correction. The accuracy of measuring the height of fault scarps can reach 0.22m, which meets the need of high-precision quantitative research of active tectonics. It provides great convenience for rapidly obtaining fine geometry, profiles morphology, vertical dislocations of fault and important reference for sites selection for trench excavation, slip rate, and samples. This method has broad prospects in the study of active tectonics.     

江西柘林水库春季浮游藻类、叶绿素a与环境因子的分布、关系及意义

江西柘林水库是长江中游的大型峡谷型旅游性水库,库容79.2×10~8m~3,长115 km.2015年4月在56 km的中心库区走航和定点测量了水库表层水体浮游藻类、叶绿素a(Chl.a)浓度与溶解无机氮(DIN)浓度、溶解无机磷(DIP)浓度、溶解硅(DSi)浓度、水温、浊度和溶解氧浓度等环境因子的分布特征.结果表明:1)水库属于中营养水体,表层主要浮游藻类(细胞丰度1000 cells/L)有34种,平均生物量为0.41 mg/L.主要优势藻类(优势度≥0.02)为硅藻和蓝藻,藻类组成与DIN浓度、DIP浓度、DSi浓度和水温等环境因子关系密切,4种因子对藻类结构的解释水平达60%以上.2)水库水体Chl.a浓度具有显著的次表层叶绿素最大值(SCM)现象,SCM层深度为3~8 m,厚度为2~7 m,SCM层占整个水体的25.2%~74.1%.SCM层的藻类对营养盐吸收消耗致使DIN、DIP和DSi浓度下降,同时藻类的产氧使溶解氧浓度增加.3)水库对DSi具有显著的生物过滤器效应,中、上层约有11%~12%的DSi被生物吸收利用,从上游至下游,累积约有21%的DSi被藻类吸收沉降于库底.4)人类氮、磷排放对水库生态和水质有严重影响,毗邻县城区域水体的Chl.a和DIP浓度分别是自然河段的2.9倍和3倍左右.     

多通道相关分析用于宽频带地震仪自噪声检测

将多通道相关分析方法用于宽频带地震仪的自噪声检测,测量分析了Reftek 130、130 B和130 S三种地震数据采集器的自噪声检测结果以及14套Reftek 130 S连接Guralp CMG-3T地震计的自噪声一致性检测结果,同时给出了地震计的三轴正交性估计.结果表明:Reftek数据采集器设置为普通增益时在0.3 Hz以上频段自噪声高于Guralp CMG-3T地震计自噪声,设置为32倍高增益时在测量频段远低于地震计自噪声;测量的多台Guralp CMG-3T地震计自噪声结果在不同频段一致性差异较大,垂直向分量0.3 Hz以下频段可作为一致性比对参考频段,采集配置选择普通增益时0.3~2 Hz频段可作为数据采集器一致性比对参考频段;Guralp CMG-3T地震计三轴正交性误差估计平均在0.5°以内.     

Pore Size Distribution of a Tight Sandstone Reservoir and its Effect on Micro Pore-throat Structure: A Case Study of the Chang 7 Member of the Xin’anbian Block,Ordos Basin,China

Pore distribution and micro pore-throat structure characteristics are significant for tight oil reservoir evaluation, but their relationship remains unclear. This paper selects the tight sandstone reservoir of the Chang 7 member of the Xin’anbian Block in the Ordos Basin as the research object and analyzes the pore size distribution and micro pore-throat structure using field emission scanning electron microscopy(FE-SEM), high-pressure mercury injection(HPMI), highpressure mercury injection, and nuclear magnetic resonance(NMR) analyses. The study finds that:(1) Based on the pore size distribution, the tight sandstone reservoir is characterized by three main patterns with different peak amplitudes. The former peak corresponds to the nanopore scale, and the latter peak corresponds to the micropore scale. Then, the tight sandstone reservoir is categorized into three types: type 1 reservoir contains more nanopores with a nanopore-to-micropore volume ratio of 82:18;type 2 reservoir has a nanopore-to-micropore volume ratio of 47:53;and type 3 reservoir contains more micropores with a nanopore-to-micropore volume ratio of 35:65.(2) Affected by the pore size distribution, the throat radius distributions of different reservoir types are notably offset. The type 1 reservoir throat radius distribution curve is weakly unimodal, with a relatively dispersed distribution and peak ranging from 0.01 μm to 0.025 μm. The type 2 reservoir’s throat radius distribution curve is single-peaked with a wide distribution range and peak from 0.1 μm to 0.25 μm. The type 3 reservoir’s throat radius distribution curve is single-peaked with a relatively narrow distribution and peak from 0.1 μm to 0.25 μm. With increasing micropore volume, pore-throat structure characteristics gradually improve.(3) The correlation between micropore permeability and porosity exceeds that of nanopores, indicating that the development of micropores notably influences the seepage capacity. In the type 1 reservoir, only the mean radius and effective porosity have suitable correlations with the nanopore and micropore porosities. The pore-throat structure parameters of the type 2 and 3 reservoirs have reasonable correlations with the nanopore and micropore porosities, indicating that the development of these types of reservoirs is affected by the pore size distribution. This study is of great significance for evaluating lacustrine tight sandstone reservoirs in China. The research results can provide guidance for evaluating tight sandstone reservoirs in other regions based on pore size distribution.     

甘孜-理塘蛇绿混杂岩带中段洋岛型岩石组合的发现及其对构造演化的指示意义

甘孜-理塘蛇绿混杂岩带位于西南"三江"多岛弧盆系东缘,是研究古特提斯洋发展演化的重要组成部分,一直备受地质学者瞩目。本文以甘孜-理塘蛇绿混杂岩带中段新龙-理塘地区新发现的大量洋岛型岩石组合为研究对象,通过对其岩石组合以及沉积特征分析将研究区不同类型洋岛型岩石组合依次划分为台地相村戈岩组、斜坡相达森隆洼岩组、坡脚相阿达隆岩组。通过同位素年代学和古生物化石研究表明研究区洋岛型岩石组合的形成时代从早二叠世到晚三叠世均有分布,暗示甘孜-理塘洋盆在早二叠世时期就已存在成熟洋壳,并且洋岛火山活动一直持续至晚三叠世。根据不同类型洋岛型岩石组合的分布特征以及变质变形上的差异,推测甘孜-理塘蛇绿混杂岩带中段新龙-理塘地区洋岛残片不应该归属于单个古洋岛,而应是不同时期、不同古洋岛相继俯冲、消减和就位后的残片。该项研究进一步丰富了甘孜-理塘蛇绿混杂岩带的演化内容,为正确认识甘孜-理塘洋盆构造演化过程提供新的资料和证据。     

曲线多尺度表达的Head-Tail信息量分割法

本文提出一种基于Head-Tail信息量分割的地理要素多尺度表达模型。首先通过傅里叶变换将地理线要素转换为傅里叶描述子,并通过香农信息熵理论计算其频域信息量。然后,按Head-Tail数据分布模式确定地理要素信息量的分界点,并设计函数对各个分界点所对应的傅里叶截断频率进行估计。最后,参考传统方根模型,建立以地理要素频率信息量为基础的信息方根模型,计算与各个地图层次相对应的关键尺度,实现地理要素的层次化多尺度表达。采用等高线及海岸线的数据试验表明,本文所提出的模型能够有效根据设定的比例尺对地理要素进行化简,对不同目标比例尺的简化结果体现出了良好的区分度与层次性。同时,在保证化简结果与原地理要素面积重叠比一致的情况下,本文模型所得到的结果优于传统的简化算法。     

济阳坳陷走滑伸展构造与低压含盐流体联合控藏作用研究

济阳坳陷地质构造经历了反复的拉张裂陷和挤压隆升,而使盆地内构造具有多幕次、多期性特点,导致济阳坳陷的盆地构造样式具有多样性,单纯的以盆地构造样式来分析控藏作用就显得不足,根据惠民凹陷试油实测压力数据分析,济阳坳陷存在低压含盐流体.从济阳坳陷走滑伸展构造样式的特征入手,发现油气藏的分布与走滑构造带具有一致性,再结合低压含盐流体作用,以构造一流体角度分析控藏作用,为油气勘探提供了一条新的研究思路.     

InSAR平地相位去除算法及其对DEM精度影响研究

准确有效去除干涉纹图中的平地相位是精确莺建DEM的关键.探讨了两类常见的去平地相位方法(基于地理定位和基于干涉频谱),分析了其所引起的误差影响.通过Envis砒和JERS-1两种数据的验证结果表明:在可获取精密轨道数据的情况下,基于地理定位的去平地方法能够有效去除干涉纹图中所包含的平地相位,并很好地控制最终所得的DEM误差,其效果优于基于干涉频谱的去平方法;基于干涉频谱的去平方法在干涉频谱平均空间频率为0时,所引起的DEM误差相对较小;在精密轨道数据缺乏的情况下,两种方法均不能满足重建DEM精度要求.     

应急服务空间数据集成研究进展

第21届国际摄影测量与遥感大会（ISPRS）于2008年7月在北京召开。大会共举办了10个大类275场次的学术交流活动,共收集论文全文1881篇。其中应急服务空间数据集成主题共收录来自中国、加拿大、日本、德国、法国、意大利等9个国家的18篇会议论文,围绕应急服务信息快速获取、应急服务信息共享与互操作、应急服务决策支持系统、灾害情景分析、应急响应空间数据基础设施建设等方面展开了系统研究,这基本反映了该主题的研究现状和发展前沿。     

桌面式虚拟环境与真实环境中个体特征影响空间认知能力的差异分析

利用虚拟地理环境模拟、表达和重构客观真实环境是当前空间认知科学领域的主要试验研究范式之一.针对人们在虚拟环境和真实环境中的认知表现是否一致的问题,本文以桌面式虚拟环境和真实环境为试验场景设计对照试验,将空间认知分为格局认知、对象认知和空间响应3个维度,通过设计认知试验,分析两种环境下参与者的空间认知差异,探究个体特征对...