Geostatistical analysis of soil moisture measurements and remotely sensed data at different spatial scales

The European remote sensing satellite (ERS-2) synthetic aperture radar (SAR) data was used for temporal monitoring of soil moisture at Sukhothai, Thailand. Higher correlations were found between the observed soil moisture and the radar backscattering coefficient. The soil moisture distribution shows great variation in space and time due to its stochastic nature. In order to obtain a better understanding of the nature and causes of spatial variation of soil moisture, the extensive soil moisture measurements observed in Thailand and also remotely sensed ERS-2 SAR data were used for geostatistical analysis. The observed soil moisture shows seasonal variations with mean varying from 3.33 %v/v (dry season) to 33.44 %v/v (wet season). The spatial geostatistical structure also shows clear seasonal variations in the geostatistical characteristics such as range and sill. The sills vary from 1.00 (%v/v)² for the driest day to 107.57 (%v/v)² for one of the wet days. The range or the correlation lengths varies between 46.5 and 149.8 m for the wettest and driest periods. The nugget effect does not show strong seasonal pattern or trend but the dry periods usually have a smaller nugget effect than the wet periods. The spherical variogram model fits the sample variograms very well in the case of soil moisture observations while the exponential model fits those of the remotely sensed data. The ranges observed from the observed soil moisture data and remotely sensed data at the same resolution are very similar. Resolution degradation affects the geostatistical structure of the data by reducing the sills, and increasing the ranges.     

基于2001—2015年遥感数据的天山山区雪线监测及分析

基于2001—2015年MOD10A1/MYD10A1、MOD13Q1以及相关气象数据,采用积雪持续时间比率法,监测了天山山区的季节雪线高程,分析了其变化特征及影响因子。结果表明:①近15年天山山区雪线整体呈显著上升趋势,平均高程3 680 m左右,其中,北坡、伊犁河谷、南坡季节雪线的稳定性依次减弱,平均高程分别为3 620 m、3 390 m及3 820 m;空间上雪线高程呈现南高北低、东高西低的纬度地带性分布特点。②年际尺度上,气温是影响天山山区雪线高程的主控因素,呈显著正相关,南北坡与之相同,但伊犁河谷则降水是影响其变化的主控因素,呈显著负相关;季节尺度上,夏季气温、冬季降水是影响雪线高程的主控因素,降水与其呈负相关,但气温较高的地区,夏秋季降水会促进积雪融化,使雪线高程上升;月尺度上,7月气温、1月降水对其影响最明显,且存在一定的滞后反应。③天山山区雪线高程比零度层低800 m左右,两者呈较好正相关;雪线高程与NDVI（Normalized Difference Vegetation Index）呈负相关,植被覆盖较好区域,同年NDVI与雪线高程相关性较好,植被覆盖较差区域,前一年NDVI与其相关性较好。     

结构方程模型及其在地学数据建模中的回顾与展望

结构方程模型是一种建立、 估计和检验因果关系的方法.它可以替代多重回归、 路径分析、 因子分析、 协方差分析等方法,清晰分析单项指标对总体的作用和单项指标间的相互关系,是一种主要应用于验证性模型分析的多元统计建模技术.由于能够通过可观测变量来度量潜变量得分以及分析不同子模型下潜变量之间的协同效应等优点,结构方程模型被广...     

Land cover and land use change related to shrimp farming in coastal areas of Quang Ninh,Vietnam using remotely sensed data

Rapid development of shrimp farming may lead to unrecognized and undesirable changes of land cover/land use patterns in coastal areas. Of special concern is the loss of mangrove forest in coastal areas such as Quang Ninh, Vietnam, which is adjacent to the World Heritage-listed Ha Long Bay. Understanding the status and changes of land cover/land use for coastal shrimp farms and mangrove forests can support environmental protection and decision-making for sustainable development in coastal areas. Within this context, this paper uses the 1999/2001 Landsat ETM+ and the 2008 ALOS AVNIR-2 imagery to investigate the contraction and expansion of shrimp farms and mangrove forests in coastal areas of Ha Long and Mong Cai, which now have a high concentration of intensive and semi-intensive shrimp farms. Images were separately analyzed and classified before using post-classification comparisons to detect land cover/land use changes in the study area. The results of this study found that the area of mangrove forest has been reduced by an estimated 927.5 ha in Ha Long and 1,144.4 ha in Mong Cai, while shrimp farming areas increased by an estimated 1,195.9 and 1,702.5 ha, respectively, over the same period. The majority of shrimp farms in Mong Cai were established at the expense of mangrove forest (49.4 %) while shrimp farms in Ha Long were mainly constructed on areas previously occupied by bare ground (46.5 %) and a significant proportion also replaced mangroves (23.9 %). The remarkable rate of mangrove loss and shrimp farming expansion detected in this study, over a relatively short time scale indicate that greater awareness of environmental impacts of shrimp farm expansion is required if this industry is to be sustainable, the important estuarine and coastal marine ecosystems are to be protected over the long term, and the capturing and storing of carbon in mangrove systems are to be enhanced for global climate change mitigation and for use as carbon offsets.     

Delineation of small-scale landforms relative to flood inundation in the western Red River delta, northern Vietnam using remotely sensed data

Flood susceptibility mapping using geomorphologic approaches is effective for delineating flood extent and various degrees of potential flood-affected areas. This approach is useful where the channel system and floodplain morphology change dynamically and in regions where detailed digital elevation models are not available. The first important step in flood zonation using this approach is detailed geomorphologic mapping, also called landform classification. This study aims to describe landform classification using the rule-based method of Ho et al. (Int J Geoinform 8(4):27–38, 2012) adapted to local characteristics in the western plain of the Red River delta, northern Vietnam. The original classification scheme is generally based on the moist condition classification, local land-surface parameters, and relative position indices derived from multi-temporal Landsat data and a shuttle radar topographic mission digital elevation model (SRTM DEM). This study uses average elevations and the standard deviation of elevations as local land-surface parameters rather than local relief, which was used in the study by Ho et al. (Int J Geoinform 8(4):27–38, 2012). Multi-temporal land cover classification was performed using an integrated method to effectively correct the SRTM DEM. The overall classification is consistent with manual mapping by visual comparison. The quantitative comparison between landform units and past flood-affected areas demonstrates a precise boundary delineation of landform objects using this method. The high agreement between the boundaries of landform units and flood-inundated areas suggests the applicability of this method taking advantage of readily available remotely sensed datasets in alluvial floodplains.     

川东北何家营地区三维构造模型：来自高精度线束三维资料的约束

川东北地区方斗山构造带发育典型的多重滑脱构造,中生代以来受大巴山南北向挤压与雪峰山北西向挤压叠加改造。其构造模型在区域性滑脱层的分布、不同构造变形层构造样式的厘定以及不同构造变形层在空间上耦合特征等方面存在争议,因此定量分析不同变形层构造样式的差异与空间组合特征成为研究分层变形成因机制的关键。本文应用数字高程、浅表地质信息与线束三维地震数据等资料,开展方斗山北段何家营地区地层与断裂构造解析,建立了何家营地区的三维构造模型,讨论方斗山北段多重滑脱层体系下,垂向上不同构造变形层的差异变形特征及其控制因素。研究表明：何家营地区沉积盖层中存在中-下寒武统膏盐层、下志留统泥岩层、下三叠统嘉陵江组膏盐层等3套区域性滑脱层以及二叠系煤层局部滑脱层。区域性滑脱层控制了褶皱—冲断构造的变形样式,构造在垂向解耦,形成基底、深部、中部与浅部等4套变形层。基底变形层发育指向北西的构造楔;深部变形层夹持于寒武系与志留系滑脱层之间,发育双重构造,形成低幅度背斜;中部变形层为志留系与嘉陵江组之间的高角度冲断构造,二叠系煤层作为局部滑脱层,发育顺层剪切;浅部变形层,以嘉陵江组盐滑脱褶皱为主。不同变形层的垂向叠置,共同形成了现今的高陡背斜。不同构造变形层地层能干性组合与缩短量的差异决定了构造样式的差异。软弱层传递位移,中寒武统膏盐层、志留系页岩与下三叠统膏盐层,缩短量最大,变形最强,是控制区域变形的主要滑脱层。何家营地区发育倾向南东的基底断层,不同变形层的主干断层与褶皱轴迹方向一致,均以北东、北东东向为主,反映出何家营地区构造变形主要受控于来自雪峰山方向的挤压作用。

     

Occurrence and mobility of major and trace elements in groundwater from pristine volcanic aquifers in Jeju Island,Korea

Major and trace elements in groundwater from basaltic aquifers in pristine conditions were investigated in a volcanic island to evaluate sources, sinks, and mobility of elements over a wide range of mineralization conditions with total dissolved solids from 50 mg/L to 3400 mg/L. Groundwater was highly undersaturated with respect to primary silicate minerals, indicating that dissolution of basaltic rocks may continue under conditions with precipitation of calcite and secondary silicates. Evolution of B/Cl ratio in groundwater from marine aerosols to basaltic rocks showed that the ratio could be used as a conservative tracer for interactions between water and basaltic rocks. Relative mobility (RM) of elements calculated using the concentrations of elements in the local basaltic rocks and those in groundwater showed that mobility decreased in the order of B > Rb > Na > K > Mg > Ca > Mo > V > Si > Sr > Sc > P > U > Zn > Pb > Cr > Cu > Ba > Ni > Ti > (Mn, Al, Fe, Co, Th) indicating that oxyanion-forming elements and alkali metals had the highest mobility. Compared to average RM, V had decreased mobility, and Fe and Mn had increased mobility in anoxic groundwater while V, Mo, and U had higher mobility in oxic-alkaline water. The sources of V, Cr, Cu, and Zn in rocks were estimated using the partition coefficients between minerals and basaltic melt, and the disparity between sources and mobility indicated that sinks are more important for controlling the concentrations of these elements in groundwater than the contents in the rocks. Principal component analysis (PCA) of hydrogeochemical parameters in groundwater produced three principal components (PC) which represent dissolution of basaltic rocks without significant attenuation of released solutes, higher degree of water–rock interactions resulting in oxic-alkaline conditions, and attenuation of Zn and Cu in higher pH, respectively. Spatial distribution of PCs revealed that groundwater with elevated concentrations of mobile elements was concentrated in the southwestern area and that concentrations of V and Cr were more scattered, which is likely to be controlled by pH and redox states of groundwater as well as degree of water–rock interactions.     

复杂构造区油气构造保存条件分析: 来自皖泾地1井的构造解析

下扬子地区中生代发生了多期挤压-伸展构造作用,是制约该区域油气勘探取得突破的重要因素之一。为揭示下扬子区中生代构造作用对油气保存的影响,文章通过地震剖面解释资料、野外露头调查、区域构造演化历史分析,并结合皖泾地1井获取的岩芯资料和油气显示情况综合探讨了下扬子南部地区的有利构造保存条件。地震解释剖面和地表调查结果表明下扬子南部地区晚三叠世以来主要经历了两期重要的构造作用：第一期为印支期挤压作用造成褶皱变形和逆冲断层以及隆升剥蚀;第二期为晚白垩世以来的伸展作用,形成断陷盆地和正断层活动。皖泾地1井在二叠系页岩地层中获得页岩气显示,在下三叠统殷坑组灰岩中钻遇轻质油,表明下扬子南部区域具有良好的油气富集条件和资源潜力。构造保存条件分析表明皖泾地1井位于褶皱冲断带内的向斜部位,印支期隆升剥蚀量小,晚白垩世以来伸展拉张幅度小,具有良好的封闭性和成藏条件,是有利的构造保存部位。     

Holocene sedimentation in the Skagerrak interpreted from chirp sonar and core data

High‐resolution chirp sonar profiling in the northeastern Skagerrak shows acoustically stratified sediments draping a rough‐surfaced substratum. A 32 metre long sediment core retrieved from the survey area encompasses the entire Holocene and latest Pleistocene. The uppermost seismo‐acoustic units in the chirp profiles represent Holocene marine sediments. The lowermost unit is interpreted as ice‐proximal glacial‐marine sediments rapidly deposited during the last deglaciation. The end of ice‐proximal sedimentation is marked by a strong reflector, interpreted to have been formed during latest Pleistocene time as a consequence of rapid ice retreat and drastically lowered sedimentation rate. The subsequent distal glacial‐marine sediments were deposited with initially high sedimentation rates caused by an isostatic rebound‐associated sea‐level fall. Based on correlation between the core and the chirp sonar profiles using measured sediment physical properties and AMS ¹⁴C dating, we propose a revised position for the Pleistocene/Holocene boundary in the seismo‐acoustic stratigraphy of the investigated area. Copyright © 2005 John Wiley & Sons, Ltd.     

塔里木盆地西南边缘压扭构造体系及其石油地质意义

塔里木盆地西南边缘发育甫沙-齐姆根和柯克亚-和田南2个压扭构造体系,前者主要是帕米尔弧形构造东北侧的侧向滑移与西昆仑造山带向塔里木盆地的不均匀冲断活动的联合作用结果,后者则主要与西昆仑造山带向塔里木盆地的不均匀冲断作用有关。这两个压扭构造体系主体形成于新近纪以来的喜马拉雅运动,其构造样式在平面上主要为走滑-逆冲断裂和雁列式分布的断裂与背斜,在剖面上则呈现为双重构造与反冲构造的叠加。压扭构造带所遭受的压扭作用从改善储层的储集性能、形成新的油气圈闭、促进油气运移与成藏等方面对塔里木盆地西南边缘的油气成藏发挥了积极作用,压扭构造带是油气勘探的有利构造部位。     

贵州省黔西县官寨井田地质构造特征及力学分析

黔西官寨井田主体构造为一背斜,位于关寨向斜与黔西向斜之间的隆起部位,走向NE-EW,井田受三条大断层（F1、F2、F3）切割,自然划分为三个区块：北区块（F2以北）为向N倾的单斜,地层倾角缓,断层稀少,构造简单;西南块区（F2以南、F12以西）断层发育,为构造复杂地段;南东区块（F2以南、F12以东）构造中等。通过对井田构造特征及应力场分析,认为官寨井田构造主要形成于燕山期,早期产生反时针NW-SE向的挤压,形成关寨向斜和F12等断层,从中期到晚期转为顺时针扭动,产生NE-SW向挤压,形变加剧,形成沙井背斜和F1断层,喜山期使井田内NE、NW向构造进一步演化,导致沙井背斜轴和F2断层产生弧形弯曲。根据井田构造发育特征,建议矿井开采首选地段应为沙井背斜的北翼,南翼西部构造复杂,需进一步研究断层分布规律,以正确指导煤矿的安全生产。     

准格尔煤田不连沟矿井构造特征及其对煤矿生产的影响

准格尔煤田位于鄂尔多斯盆地伊盟隆起和晋西褶曲带的转折部位,煤田内的矿井构造样式多样,而且矿井生产揭露前后构造复杂程度发生了重大变化。以不连沟矿井地质勘查和矿井揭露的褶皱、断层、岩溶陷落柱、火成岩侵入体等地质构造为主要研究对象,通过数理统计方法对矿井内的构造发育特征进行了定量或半定量评价,分析不同地质构造的形成机制、演化背景及矿井构造复杂程度变化的主要原因,统计分析不同类型地质构造对矿井采掘生产的影响,总结矿井地质构造探查经验,提出适应于该区的构造探查思路。结果表明：不连沟煤矿构造样式多样,构造发育的分区特征明显,构造组合具有耦合性;矿井中部的弧形坡折带及波状褶皱形成开始于加里东构造运动,属于黄河断裂和呼-清断裂的伴生构造;区内走向EW （或近EW向）和NW断层组合是鄂尔多斯盆地印支期S—N向挤压应力和燕山期NW—SE向挤压应力共同作用的结果。各类地质构造制约着矿井采区部署、巷道掘进、工作面回采速度,造成大量资源损失,给矿井防治水带来巨大挑战。针对类似研究区的复杂矿区,建议采用三维地震勘探扫面,井下槽波、电法勘探靶区圈定,定向钻验证的“物探、钻探,地面、井下”相结合的综合探查方案。     

盐岩地下储气库泥岩夹层分布与组构特性研究

以江苏金坛地下盐岩储气库为例,在区域地质与场地工程地质条件分析的基础上,通过盐岩及夹层分布与岩性分析、泥岩夹层全岩X光衍射试验、黏土矿物X光衍射试验及定量分析、泥岩夹层的粒度试验、崩解试验及水理试验研究表明,金坛地下储气库岩盐层夹层主要为层间夹层与层内夹层,盐岩层间夹层分布稳定,厚度较大,不溶物含量高;盐岩层内夹层层数多,厚度薄,分布不均,不溶物含量低。盐岩层间泥岩夹层的主要矿物为黏土矿物,黏土矿物的主要存在形式为伊利石/蒙脱石混成矿物;泥岩夹层主要为细粒颗粒;泥岩夹层沿层理面崩解,层状开裂软化,具有微膨胀性。对于储库水溶建腔速度、成腔形状与运营期的腔体蠕变具有重要影响。     

Evolution and deposits of a gravelly braid bar, Sagavanirktok River, Alaska

The evolution, migration and deposits of a gravelly braid bar in the Sagavanirktok River, northern Alaska, are described in unprecedented detail using annual aerial photographs, ground‐penetrating radar (GPR) profiles, trenches and cores. Compound braid bars in the Sagavanirktok River form by chute cut‐off of point bars and by growth of mid‐channel unit bars. Subsequent growth is primarily by accretion of unit bars onto their lateral and downstream margins. The upstream ends of braid bars may be sites of erosion or unit bar deposition. Compound braid bar deposits vary in thickness laterally and are thickest in medial sections and near cut banks. Compound bar deposits are typically composed of three to seven sets of simple large‐scale inclined strata, each simple set formed by a unit bar. The simple large‐scale strata contain medium‐scale cross‐strata (from dune migration) and planar strata (from migration of bedload sheets). The upstream and medial parts of compound braid bar deposits show very little vertical variation in grain size, but downstream and lateral margins tend to fine upwards. The deposits are mostly poorly sorted sands and gravels, although sands tend to be deposited at the top of the braid bar, and open‐framework gravels preferentially occur near the top and base of the braid bar. The patterns of braid bar growth and migration, and the nature of the deposits, described from the Sagavanirktok River are generally similar to other sandy and gravelly braided rivers, and consistent with the theoretical braid bar model of Bridge (1993).     

淮北煤田五沟煤矿构造特征及其演化

淮北煤田五沟煤矿位于童亭背斜西翼中段,为一向斜为主的复式褶皱构造组合,向斜的轴部呈反S形且被断层切割。在系统分析煤矿地质资料的基础上,结合区域构造演化,探讨了构造发育特征、构造演化历史及其形成机制。结果认为:①五沟矿区可以划分为北部断裂构造复杂区、中部褶皱叠加区和南部构造复杂区3个构造分区,断裂构造的组合形式主要有"入"字型、"Y"型、堑垒式及阶梯式。②矿区构造的形成及演化受区域构造控制明显,印支期NS向构造挤压作用形成了近EW向的五沟断层,末期形成五沟复向斜构造;燕山期NW—SE向强烈的挤压作用形成了区内最为显著的NE向断裂及褶皱构造;喜马拉雅期的构造伸展作用造成拉张性构造发育,同时也使区内大、中型主控断裂转变为正断层性质。     

Interpretation of gravity anomalies to delineate some structural features of Biga and Gelibolu peninsulas,and their surroundings (north-west Turkey)

On the basis of gravity data, derived anomaly traces were presented for the interpretation of some shallow structural features of Biga and Gelibolu peninsulas. Since building general understanding of subtle details about subsurface geology is of great importance considering that the study area is tectonically important, some advanced data processing techniques were implemented to gravity anomalies in a detailed manner. The procedures were performed using a MATLAB-based software package (Gravity and Magnetic Interpretation – GMINTERP). First, a finite element method was utilised to produce the residual data-set which is expected to reflect short wavelength anomalies arising from shallower geological structures, and thereafter some derivative-based algorithms were executed to analyse the residual data. The general anomaly patterns obtained from the applications clearly corresponded to the well-known surface geology map of the study area. Derivative-based anomaly maps put forward some findings about the existence of an old caldera structure in the western part of the Biga Peninsula. Additionally, abrupt lateral changes in anomaly amplitudes indicated the presence of some major structural discontinuities. Thus, findings yielded to make significant geological interpretations that might be important for further investigations. This study also showed that GMINTERP software package proved useful in assisting geological interpretation using geophysical potential field data-sets.     

黑龙江省五常地区重力场特征及区域地质构造特征分析

区域重力调查工作,对断裂的空间位置及区域构造分区是主要地质任务之一。本文利用布格重力异常,进行深部场、浅部场的分析。通过场的分离对区域场与剩余场特征分析;经过异常转换信息划分区域地质构造界线,特别是对Ⅲ级构造单元的划分从重力异常成果中,获得三高二低趋势,通过深大断裂划分确定区域地质构造分区界线,从而重新划分该区Ⅲ级以上构造区块位置,本次工作成果将为今后该区研究工作带来新的信息。     

库车坳陷克拉苏构造带协同变形机制及盆山耦合关系

克拉苏构造带构造非常复杂,经过30余年的油气勘探开发,构造规律不清楚、构造圈闭不落实的问题仍然非常突出。本文通过大量三维地震资料的构造解释、建模及实钻资料验证,发现克拉苏构造带在剖面上呈分段分层变形、平面上呈雁列式展布特征。提出克拉苏构造带两种协同变形机制,较好地解释了在膏盐层调节作用下盐上、盐层、盐下3个构造层的差异变形现象。结合遥感影像及重力异常影像分析了盆山耦合关系,提出了南天山造山带的差异隆升推覆作用,南部温宿、新和、牙哈古隆起的阻挡作用和古近系膏盐层的调节作用是变形的3个主要影响因素,并据此较好地解释了克拉苏构造带构造圈闭平面展布格局。     

黔西南泥堡金矿床构造解析及构造控矿作用

泥堡金矿床地处黔西南碳酸盐岩台地相区,赋矿围岩主要为玄武质火山碎屑岩,以断控型矿体为主、层控型矿体为辅,是滇黔桂"金三角"地区典型的卡林型金矿床之一。详细的野外填图和研究表明,构造是其最主要的控矿要素之一。泥堡金矿区构造类型以断层和褶皱为主,构造线以北东向为主,北西向为辅。矿床受区域性的北东东向潘家庄断裂控制,但矿体主要受次一级的断层和褶皱控制,其中枢纽北东东向二龙抢宝背斜与北西向背斜叠加形成的穹窿构造是层控型金矿体的主要构造控制因素;断控型金矿体主要受控于F_1逆断层,逆冲断层+上盘牵引背斜构造是泥堡金矿最典型的构造控矿组合样式。印支期造山挤压奠定了矿区北东东向的总体构造格架,燕山期叠加了北西向构造。F_1虽总体表现为逆断层性质,但在燕山晚期叠加了正滑运动,并形成了张性空间,有利于的成矿流体运移和金沉淀。根据矿床构造控矿规律分析,提出F_1北部的次级断层F_(1-1)及其上盘牵引背斜为金矿有利的找矿靶区,有待今后工程验证。     

准格尔煤田串草圪旦煤矿5号煤元素地球化学特征

为研究准格尔串草圪旦5号煤微量元素地球化学特征,采用光学显微镜、扫面电子显微镜和X射线衍射（XRD）方法观测煤中矿物组成及形态特征,应用电感耦合等离子质谱（ICP MS）方法测定煤中多种微量元素含量,运用数理统计方法研究微量元素在煤中的赋存特征。结果表明：5号煤中Li、Be、F、U、Hg 5种元素相对富集,含量高于研究区6号煤及中国煤中含量水平。5号煤中Li、F、Ga、Se无机亲和性强,Be、As、U为亲有机元素;Hg与硫含量显著正相关。各元素在煤中主要以有机结合态、无机结合态和硫化物结合态赋存。