基于时序InSAR的京津高铁北京段地面沉降监测

京津高铁是中国第一条高速运行的城际铁路,其安全运行对轨道的平顺性有着严格的要求。地面沉降,尤其是不均匀地面沉降会引起部分路基和桥梁变形,威胁着高速铁路的运营安全。合成孔径雷达干涉测量技术可以大范围监测地表形变,对高速铁路沿线地面沉降具有较好的监测能力。本文以45景高分辨率TerraSAR-X 数据为基础,采用 PS-InSAR技术监测京津高铁北京段沿线地面沉降,获取京津高铁北京段沿线地面沉降的分布信息,从动静载荷视角结合北京地区地下水、断裂带、地质条件和含水层系统介质等数据,综合分析高铁沿线不均匀地面沉降的原因,为京津高铁的安全运营提供技术支撑。研究结果表明：京津高铁北京段沿线地面沉降发展在空间上存在一定差异性,北京南站至十里河区间,年沉降速率小于10 mm/a; 至十八里店区间,年沉降速率在10~40 mm/a范围内浮动;过亦庄站至东石村以东区间,最大年沉降速率达到90 mm/a;至永隆村以西,年沉降有所缓解,往东至坨堤村,沉降较为稳定,年沉降速率小于10 mm/a。地下水超采是沿线区域地面沉降的主要因素,动静载荷共同作用下对地面沉降产生一定的影响,沿线地面沉降一定程度上受到南苑—通县断裂带和旧宫断裂带构造控制,沉降量较大的路段位于粘土层较厚的大兴迭隆起。     

Experimental study on bar formation in a scouring process

Bars are widely thought to be large sediment bodies formed under sediment supply. Nevertheless, little has been known on how they form in sediment scouring processes. In this study, we carried out a flume experiment to study the formation of bars without sediment supply. The experiment was divided into two stages. In the first stage, the discharge was successively increased; in each discharge step, the disturbance from upstream and downstream boundaries had little influence on the flow. We observed that no bars formed in this stage. In the second stage, we kept a small discharge at the flume inlet. In this stage, the bars emerged from the fluctuated bed topography with millimeter-scale bed forms by headcut initiated from the outlet. As the headcut migrated upstream, the accompanying undercut gradually forced the unconfined flow run into the low-elevation zone, lowering the water level and inducing the outcrop of regions free from the incision (i.e., bars). At the end of the experiment, a relatively stable topography formed under the joint effect of the upstream migrating headcut, the following undercut after the headcut and the lateral erosion on the emerged bars. The requirements for the formation of bars and the distinctive characteristics of the bars induced by headcut were investigated. This study shows that bars can form in a scouring process under appropriate conditions, and the headcut may be one of the precipitating factors for the formation of bars in natural rivers.     

Study On Development And Application Of A Regional Pbl Numerical Model

A regional scale (a few km to a few hundred km, minutes to days)planetary boundary layer (PBL) numerical model (RPBLM) has been successfully developed to simulateprecisely the boundary-layer three-dimensional characteristics. The RPBLM model with a high-resolutionnon-hydrostatic E - turbulence closure scheme has been applied to diagnose and prognosticate the PBL characteristicsover a complex underlying surface in the Hong Kong area of 60 km × 48 km. It is shown that the RPBLMmodel can be used to simulate the PBL characteristics including wind, temperature, water vapour andturbulence over such a complex underlying surface and that the simulated result is reasonably in agreementwith observations.     

济阳坳陷古近系成岩作用及其对储层质量的影响?

大量的储层分析化验资料研究表明，济阳坳陷古近系砂岩储层经历了压实、胶结等多种成岩作用。压实作用以机械压实为主，压溶作用较少。胶结作用主要有十分普遍的石英次生加大胶结、碳酸盐胶结、粘土矿物胶结。碳酸盐胶结物有早、晚两期，早期泥晶方解石主要分布在浅层，连晶方解石充填的深度分布范围大，中深部最为发育。溶蚀作用主要有碳酸盐胶结物、长石颗粒和少量岩屑溶蚀。储层孔隙经历了由原生到次生的演化过程，在成岩演化过程中，长石的溶蚀作用、碳酸盐矿物的沉淀与溶解作用是影响孔隙大小的关键因素，早期方解石的胶结有利于后期次生孔隙的发育。不同凹陷次生孔隙发育的深度不同。在济阳坳陷西部的惠民凹陷次生孔隙主要发育于1500-2400m深度，向东至东营凹陷则主要发育于1650-2450m，再向东到沾化凹陷为2300-3500m，车镇凹陷为2200-2700m。从西向东、由南向北次生孔隙的发育深度逐步增大是受盆地沉积沉降中心的迁移规律控制的。     

京北云蒙山变质核杂岩南东侧剥离断层带的构造热演化

以云蒙山变质核杂岩东侧的河防口低角度正断层为研究对象,通过矿物(黑云母)的变形特征和形成环境分析,获得了该断层带上的构造热演化环境:温度为780～860℃,压力约为7.3×108～8.6×108Pa.提出云蒙山变质核杂岩的成因机制是,在区域伸展背景下,处于半固结状态的云蒙山花岗岩在东南侧卷入河防口-水峪伸展型韧性剪切带,使花岗岩发生中高温条件的韧性变形;之后,该韧性剪切带在隆升过程中不断向浅层次过渡,形成了一些浅层次的脆性伸展变形构造.     

Main Factors Affecting the Distribution of the Macroscopic Destruction Field of Earthquake

It is proposed that some possible macroseismic epicenters can be determined quickly from the relationship that the microseismic epicenters located by instruments bear with faults.Based on these so-called macroseismic epicenters,we can make fast seismic hazard estimation after a shock by use of the empirical distribution model of seismic intensity.In comparison with the method that uses the microseismic epicenters directly,this approach can increase the preccision of fast seismic hazard estimation.Statistical analysis of 133 main earthquakes in China was made.The result shows that the deviation distance between the microseismic epicenter and macroseismic epicenter falls within the range of 35km for 88% earthquakes of the total and within the range of 35to 75km for the remaining ones.Then,we can take the area that has the microseismic epicenter as its center and is 35km in radius as the area for emphatic analysis,and take the area within 75km around the microseismic epicenter as the area for general analysis.The relation between the 66 earthquake cases on the N-S Seismic Belt in China and the spatial distribution characteristics of faults and the results of focal mechanism solution were analyzed in detail.We know from the analysis that the error of instrumental epicenter determination is not the only factor that gives effects to the deviation of the macroseismic epicenter.In addiditon to it,the fault size,fault distribution,fault activity,fault intersection types,earthquake magnitude,etc,are also main affecting factors.By sorting out ,processing and analyzing these affecting factors,the principle and procedures for quickly determining the possible position of the macroseismic epicenter were set up.Taking these as a basis and establishing a nationwide database of faults that contains relevant factors,it is possible to apply this method in practical fast estimation of seismic hazard.     

基于GIS的岩溶区土地利用的地形梯度分布研究——以酉阳县板溪乡为例

基于 RS 和 GIS 技术,采用地形位指数、分布指数和土地利用程度综合指数,探讨了2002、2011两年重庆市酉阳县板溪乡不同地形梯度土地利用结构的变化特征和定量分析了土地利用程度。结果显示：建设用地、耕地和水域对地形条件的选择性较强;建设用地主要聚集在海拔〈850 m、坡度〈15°176;的区域,耕地主要聚集在海拔〈1050 m 和坡度〈25°176;的区域,5和7级地形位为制约水域分布的地形条件;2011年,灌木林地在海拔650-1250 m、坡度〉15°176;的区域集中增加。总体上,该研究区的土地利用程度较高,但仍然存在耕地分布不合理的现象。     

K-feldspar rich shales from Jurassic bedded cherts in southeastern Slovenia

The study area in southeastern Slovenia is part of the transitional zone between the internal and the external Dinarides. Within Jurassic bedded cherts there are up to 2 cm thick shale intercalations, consisting of laminated, soft, fine-grained, green to brown material whose origin has been in question. In the majority of Tethyan cherts, the interbedded material is reported to be volcanogenic and/or terrigenous, although a detailed mineralogical analysis of the material is lacking. An XRD analysis confirmed the presence of quartz, illite, chlorite and K-feldspar, which is the prevailing component in some samples. Major and trace element data exclude both a volcanogenic and an hydrothermal origin. Several discrimination diagrams indicate the upper crustal terrigenous nature of shales and a biogenic silica source. The source material was probably from a Variscan crust, which at the time of deposition had already been weathered to kaolinite, and some sporadic muscovite. The MnO/Al₂O₃ ratio suggests a slow sedimentation rate of cherts and a faster one for shales, which probably settled from distal turbidity currents. The negative Ce anomaly indicates prolonged contact with ocean water. Sediments were deposited on a Tethyan passive margin, originally as silica-rich carbonate beds intercalated with mud. During late diagenesis, the mixing of marine and meteoric waters caused the further silicification of limestone and simultaneous potassium enrichment of shale which led to their alteration into illite or chlorite and, in sediments already rich in K-minerals, into K-feldspar.     

基于深度信念网络的地质实体识别方法

地质实体作为地质信息表达的核心要素,对其准确识别是地质文本数据挖掘和应用的重要基础。本文通过分析各种类型文本数据中地质实体信息的描述特点,构建了地质实体信息的标注规范和语料库,设计了基于深度信念网络(Deep Belief Networks)的地质实体识别模型,解决了文本数据中地质实体信息的结构化、规范化处理问题。以矿产资源地质调查报告为实验数据,对本文的地质实体识别方法性能进行了评估分析。结果表明,深度学习模型能够在较小规模语料库的基础上,达到较好的地质实体识别性能。     

基于WorldView-Ⅱ高分数据的盐湖矿化度含量定量反演研究——以尕斯库勒盐湖为例

鉴于盐湖水体矿化度含量定量反演研究较少,且中、低空间分辨率遥感数据反演的矿化度含量精度偏低,文章以柴达木盆地西部尕斯库勒盐湖为例,基于WorldView-Ⅱ高空间分辨率遥感数据和实测矿化度数据,开展了盐湖湖表水体矿化度含量定量反演技术研究。通过开展盐湖水际线提取、盐湖水体矿化度光谱诊断特征分析、矿化度识别遥感指数构建、矿化度遥感信息分离和线性回归模拟,构建了盐湖矿化度含量定量反演模型。经评价,模型反演精度为96.61%。研究结果表明,基于WorldView-II高分数据定量反演盐湖矿化度含量的方法是有效的,该方法对于快速定量识别盐湖矿化度含量,降低盐湖矿化度调查和分析成本,预测富矿水域具有十分重要的意义。