基于ASTER数据的蚀变矿物信息提取——以哈密黄山铜镍矿区为例

在分析哈密黄山铜镍矿区典型地物波谱特征的基础上,设计了基于ASTER数据的蚀变信息提取流程,详细论述了对4组含不同离子或基团的常见蚀变矿物应用主成分分析(PCA)进行蚀变信息提取、采用光谱角制图法(spectral angle mapper,SAM)进行干扰异常筛选的“SAM去干扰异常主分量门限技术”.4组(9种)蚀变矿物包括:含Fe离子的矿物(针铁矿、赤铁矿)、含CO23-基团的矿物(方解石、白云石)、含Al - OH基团的矿物(白云母、蒙脱石、高岭石)以及含Mg - OH基团的矿物(绿泥石、绿帘石).蚀变矿物信息提取结果表明,“SAM去干扰异常主分量门限技术”方法可行,对ASTER数据的应用效果与实际情况比较吻合,充分证明ASTER在短波红外范围内具有很强的矿物刻画能力.     

Variational characteristics of shear-wave splitting on the 2001 Shidian earthquakes in Yunnan, China

Introduction In the crust there exist widely vertical nearly-parallel fluid-saturated microcracks, which are nearly parallel. Shear-wave splitting can be observed when shear-wave travels through this kind of microcrack structure. Shear-wave splitting could be adopted to monitor the earthquake activity since its pattern is very sensitive to variation of crustal stress (GAO, et al, 1995, 1996), however, it needs lots of reliable 3-component waveform data. Previous studies mainly used some temp…     

A spectral index for land degradation mapping using ASTER data: Application to a semi-arid Mediterranean catchment

Flagrant soil erosion in Morocco is an alarming sign of soil degradation. Due to the considerable costs of detailed ground surveys of this phenomenon, remote sensing is an appropriate alternative for analyzing and evaluating the risks of the expansion of soil degradation. In this paper, we characterize the state of land degradation in a small Mediterranean watershed using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and ground-based spectroradiometric measurements. The two visible, the near-infrared and six shortwave infrared bands of the above sensor were calibrated using ground measurements of the spectral reflectance. Field measurements were carried out in the Saboun experimental basin located in the marl soil region of the Moroccan western Rif. The study leads to the development and evaluation of a new spectral approach to express land degradation. This index called Land degradation index (LDI) is based on the concept of the soil line derived from spectroradiometric ground measurements. In this study, we compare LDI and the spectral angle mapping (SAM) approaches to assess and map land degradation. Results show that LDI provides more accurate results for mapping land degradation (Kappa = 0.79) when compared to the SAM method (Kappa = 0.61). Validation and evaluation of the results are based on the thematic maps derived from the ground data (organic matter, clay, silt and sand) by kriging, DEM, slope gradient and photointerpretation.     

Monitoring and analysing the Emirate of Dubai’s land use/land cover changes: an integrated,low-cost remote sensing approach

This study presents a modified low-cost approach, which integrates the spectral angle mapper and image difference algorithms in order to enhance classification maps for the purpose of monitoring and analysing land use/land cover change between 2000 and 2015 for the Emirate of Dubai. The approach was modified by collecting 320 training samples from QuickBird images with a spatial resolution of 0.6 m, as well as carrying out field observations, followed by the application of a 3?×?3 Soble filter, sieving classes, majority/minority analysis, and clump classes of the obtained classification maps. The accuracy assessment showed that the targeted 2000, 2005, 2010 and 2015 classification maps have 88.1252%, 89.0699%, 90.1225% and 96.0965% accuracy, respectively. The results showed that the built-up area increased by 233.721?km² (5.81%) between 2000 and 2005 and continues to increase even up and till the present time. The assessment of changes in the periods 2000–2005 and 2010–2015 confirmed that net vegetation area losses were more pronounced from 2000 to 2005 than from 2010 to 2015, dropping from 47,618 to 40,820?km², respectively. This study is aimed to assist urban planners and decision-makers, as well as research institutes.     

多光谱遥感技术预测矿产资源的潜能——以蒙古国欧玉陶勒盖铜金矿床为例

建议把蚀变遥感异常作为一个新的找矿参数,文中讨论了蚀变遥感异常的地质基础和光谱前提。在矿床地质学和蚀变矿物光谱参数特征的基础上,编制了一张用于蚀变遥感异常提取及对其地质解释的表格。设计了从ETM+和ASTER数据中提取羟基蚀变矿物组合信息的独特流程方案。这个方案称之为"去干扰异常主分量门限化技术",文中示以简化的流程图。ETM+数据用来研究位于欧玉陶勒盖铜金矿床东北部的汉保各德中酸性火成杂岩体岩性特征,ASTER近红外和短波红外数据用来提取欧玉陶勒盖斑岩铜金矿矿床及其近区的羟基异常,通过选择性主分量分析判断欧玉陶勒盖铜金矿矿床的矿床类型为斑岩型。已知矿区各矿体的羟基异常都十分清晰,此外在矿床西部还发现了三个新的有希望的羟基异常。此工作进一步展示出多光谱遥感技术对于金属矿床的预测具有极好的潜能。     

基于ASTER数据的内蒙古东乌珠穆沁北部地区遥感蚀变信息提取

ASTER数据在短波红外和热红外波段光谱信息明显优于ETM,使得在ASTER波段范围内能够更为详尽地刻画地物波谱,尤其是具有特征谱带的岩石和矿物.选择内蒙古东乌珠穆沁旗北部地区为工作区域,设计了用光谱角制图法提取矿化蚀变信息的技术方案.通过波段组合和增强处理,ASTER数据对含Fe-OH(如黄钾铁矾,含铁白云母)、Al-OH(如粘土类矿物、明矾石、绿泥石、绢云母)和Fe~(3+) (如褐铁矿,赤铁矿)3种类型蚀变信息的刻画能力明显比ETM更好.野外查证了提取结果的可靠性.     

基于CGE模型的碳税政策模拟——以广东省为例

科学设置碳税政策是控制二氧化碳排放量和推动能源结构优化的重要基础,文中以广东省为例,利用2012年的广东省投入产出表、广东统计年鉴、广东财政年鉴、中国统计年鉴等数据构建社会核算矩阵,通过构建静态的可计算一般均衡模型（CGE),进行区域的碳税政策模拟,分析不同程度的碳税税率对化石能源消费量及各宏观经济变量的影响。结果表明：征收碳税对减排效果有明显的正向作用,当碳税水平为60元/t时,广东省减排效果为3.90%;在碳税定价上,60元/t较为合适;减排贡献率最高的化石能源为煤炭,其次为石油,最低为天然气;碳税冲击下能源消费量下降,最明显的为煤炭,其次是火电;碳税冲击也能显著减少各部门对煤炭的消费量;碳税政策对广东省GDP和社会福利有负向作用,但对总体碳排放强度有正向作用。未来广东省应严格控制煤炭消费量,同时对火电部门进行低碳改造。     

从高光谱遥感影像提取植被信息

遥感可以快速有效地监测大面积植被的种类、特性、长势等各类信息。高光谱遥感数据因其特有的高光谱分辨率特性使其在植被生态环境领域具有极大的应用潜力。植被信息作为生态环境评价的重要参数对区域生态环境的监测和建设具有重要的意义。本文基于云南省鹤庆县北衙的高光谱遥感数据用SAM方法对植被信息进行了提取,参考光谱使用ASD光谱辐射仪采集的植被光谱曲线。文中对高光谱遥感影像的辐射定标和大气校正进行了研究,针对影响光谱辐射仪采集的主要因素采取了相应的措施,并对光谱曲线分类及参考光谱曲线的选取进行了研究。将选取出的参考光谱曲线与大气校正后的遥感影像进行SAM匹配提取出植被信息,经过与实地调查资料比较并计算总体精度和kappa系数,计算结果达到预期精度。最后将分类结果转换为矢量图,经过投影转换为大地坐标后制作出北衙植被分布图。     

甘东南地区地壳介质各向异性特征

利用甘肃数字地震台网(2001 -2008年)的观测资料,采用SAM分析方法进行剪切波分裂,获得了甘东南地区7个台站319条剪切波分裂参数.结果表明甘东南地区快剪切波平均偏振方向与该区域最大主压应力方向一致,是区域应力环境的较好描述;位于活动断裂上或几条活动断裂交汇部位的台站的快剪切波偏振优势方向大多数与对控震的活动断裂走向一致;复杂的局部构造会影响剪切波分裂结果,造成偏振优势方向与主要活动断裂走向不一致,或与区域主压应力相差较大的现象.     

南半球环状模气候影响的若干研究进展

南半球环状模是南半球热带外地区环流变率的主导模态。由于南半球环状模在空间上的大尺度特征,全球多个地区的气候均与南半球环状模的变化有关。探讨南半球环状模的气候影响,是近几十年来得到广泛关注并迅速发展的新方向。围绕这个方向,分别回顾了南半球环状模对南半球和北半球气候影响的研究进展,重点阐述了南半球环状模对中国气候影响的相关工作,并从长期变化尺度上,列举了南半球环状模与气候变化方面的研究成果。纵观近几十年的研究发现,针对南半球环状模对南半球的气候影响,目前已有比较系统的认识。总体而言,在年际尺度上,南半球环状模可以通过影响垂直环流和风暴轴的位置,改变表面风速对下垫面的热力和动力驱动作用,进而对南半球的海-气-冰耦合系统产生调控。这种调控多表现出纬向对称性,同时也存在纬向非对称的局地特征。在气候变化的尺度上,南半球环状模是过去半个世纪里南半球气候变化的主要驱动力之一。关于南半球环状模对北半球尤其是中国气候的影响问题,目前也取得了许多有意义的结果。例如,南半球环状模对东亚、西非、北美的夏季风和东亚冬季风均有作用,并且可以调控中国春季华南降水等。海-气耦合过程在南半球环状模对北半球气候的影响中扮演着重要角色,与南半球环状模信号的跨季节存储和由南半球向北半球的传播均有密切关系。但是,与南半球相比,南半球环状模对北半球气候影响的研究,还有许多问题值得深入讨论和研究：一是体现在对南半球环状模信号向北传播机制上的深入认识,二是将南半球环状模的信号作为因子在季节气候预测中的实践。