基于面向对象方法的Sentinel-1A SAR在洪水监测 中的应用

开展Sentinel-1A SAR数据在洪水淹没范围提取和水体变化监测方面的应用研究,对科学有效地管理洪涝灾害有重要意义。合成孔径雷达以其不受天气影响、能穿透云层、覆盖面积广等特点成为灾害监测的重要数据来源。面向对象的方法能有效解决影像的椒盐现象被广泛运用于信息提取研究。本文基于Sentinel-1A SAR数据,利用面向对象的方法构建洪水淹没范围提取流程,绘制灾前、灾中、灾后水体变化监测图,对比分析基于传统像元的提取方法,实现对广西临桂会仙岩溶湿地区域不同时期洪水动态监测。研究表明,Sentinel-1A SAR数据在洪水监测领域有巨大的应用潜力,相较于传统基于像元的方法,面向对象的方法能有效抑制杂斑生成,提高空间信息的利用效率,具有更好的提取精度。     

Sentinel-1 TOPS影像干涉处理与形变监测

Sentinel-1A IW模式可获取250 km宽的SAR影像,且噪声小、重访周期短。然而Sentinel-1A的TOPS成像方式造成SAR影像方位向多普勒频率变化较大,干涉数据处理对影像配准要求极高。提出基于DEM和精密轨道的TOPS影像高精度配准和拼接方法,实现TOPS影像干涉变形监测的数据处理,并利用升降轨TOPS影像数据获取门源地震雷达视线向一致的同震变形,证实本文数据处理方法的正确性。     

湛江港水体夏季后向散射特性

【目的】研究湛江港水体夏季后向散射特性。【方法】利用2017年夏季湛江港海域的航次数据,采用实验与对比分析的方法,研究湛江港海域水体的后向散射系数的光谱特性、空间分布,分析后向散射系数与悬浮泥沙浓度的关系。【结果】湛江港海域水体的后向散射系数的光谱模型符合乘幂的形式,波长指数(n)为1.61。后向散射系数的空间分布呈现近岸高值,外海低值的特点。后向散射系数与悬浮泥沙浓度存在良好的线性回归关系,决定系数(R2)为0.707 2。【结论】水体的后向散射系数可用于水体悬浮泥沙浓度的遥感反演。     

Sentinel-1 SAR在洪水范围提取与极化分析中的应用研究

在洪水灾情监测中,快速准确的获取淹没区域和洪灾面积,对防汛救灾和灾后重建工作具有重要价值。本文以2017年美国圣路易斯洪水为例,基于Sentinel-1 SAR数据,利用变化检测和阈值相结合的方法实现大范围洪水淹没提取,将VV/VH极化数据分别与从同期Sentinel-2光学影像中获取的洪水淹没范围进行比较,评定极化方式的洪水适用性优劣程度。不同的SAR极化数据对洪水监测的适用性不同,通过绘制各极化不同时期的后向散射横断面线来分析多极化中的散射响应特征。研究表明：Sentinel-1 VV/VH极化数据均能以超过82%的高精度识别出洪水,VV极化洪水提取时产生的误判更少;在同样的区域,相较于VH,Sentinel-1 VV极化信号的散射程度小了约28%,在洪水中的信息敏感,更适用于洪水灾害的淹没范围监测。     

多源SAR遥感影像海上溢油业务化监测系统研究

随着海上石油运输业和海洋石油工业的迅速发展,海上溢油事故频繁发生,造成了巨大的生态和经济上的损失,因此,实时监测溢油信息对灾害防控具有重要意义。本文基于多源SAR影像数据,开展了溢油遥感监测研究,构建了基于GIS的海洋溢油业务化监测系统。系统基于GDAL对原始数据进行解析,实现影像输入和几何校正等处理;在此基础上,封装多尺度图像分割算法和灰度对比度特征提取算法,对SAR影像数据进行分块、分割、溢油识别、合并及参数赋值等自动化处理,实现溢油信息提取的一键化处理;面向溢油监测应用需求,制作各类标准化产品,自动添加制图整饰要素、影像参数、溢油面积和溢油源等各类信息,并实时生成专题快报。     

高分辨率SAR数据在河北省城市形变监测中的应用

针对传统形变监测难以在短时间内进行大面积形变监测的问题,结合基于时间序列的雷达差分干涉测量(PS-InSAR)技术,以TerraSAR-X数据为例,重点研究了高分辨率SAR数据在城市地表形变监测中的应用,并对石家庄市、沧州市城区进行了监测,使用了2013年和2014年间各37景数据,采用了SARPROZ软件进行数据处理。实验结果显示,在石家庄市和沧州市各有三处较大形变区域。根据历史水文地质数据资料对比显示,产生形变的区域主要为地下水漏斗区域和大型建筑施工区域。在对石家庄市的分析结果中还发现,由于建筑施工造成了高铁沿线周边区域的较大沉降。此外,经过与沧州市历史沉降资料对比发现,传统沉降区已得到了有效的控制。总体而言,高分辨率SAR影像差分干涉技术为城市大面积地表形变分析提供了一种行之有效的监测手段,对传统沉降区的持续监测、高铁运行、地铁施工建设等具有重要参考意义。     

基于主成分变换的星载升降轨极化SAR数据水体提取方法

利用光学遥感技术可以快速高效地获取大范围的地表水体信息,但是在洪灾监测等应用中,常常伴随多云、降雨等恶劣天气,难以及时获得高质量的光学遥感图像。合成孔径雷达（Synthetic Aperture Radar, SAR）技术具有全天时、全天候的特点,不受阴雨天气的影响,相比光学遥感具有明显的优势。本文首先总结和分析了目前基于星载SAR数据提取水体的方法和存在的问题,以Sentinel-1数据为例,为了弥补单极化阈值法和哨兵一号双极化水体指数（Sentinel-1 Dual-Polarized Water Index,SDWI）方法的不足,提出了双极化第一主成分水体指数（Dual-Polarized First-Principal-Component Water Index, DFWI）。其次,为了解决雷达阴影容易与水体相互混淆的问题,提出了3种升降轨极化SAR水体提取方法：升降轨VH极化方法（AscendingDescending VH-Polarization Water Index, AD-VH）、升降轨VV极化方法（Ascending-Descending VV-Polarizat...     

SIFT与粗差剔除算法相结合的机载SAR影像匹配研究

SAR影像匹配是SAR数据处理的重要环节,但是,SAR影像匹配成功率、正确率及精度较低。通过SAR影像匹配,建立SAR匹配像对,对雷达立体观察和立体测量有重要的意义。在机载SAR影像匹配中,应用SIFT 算法,获得较稳定的特征,并结合2D单应变换的RANSAC算法剔除误匹配点对;选取三组不同类别的机载SAR影像数据,利用SIFT 和粗差剔除相结合的算法,通过VC++和OpenCV编程,提取出特征稳定且均匀分布的同名点对,完成机载SAR影像匹配实验。结果表明,对于含有人工建筑物的机载SAR影像,SIFT 算法可有效地提取大量稳定的匹配点对,其正确率高;对于含有自然植被的机载SAR影像,SIFT 算法可有效地提取较多稳定的匹配点对,其正确率较高;由于SIFT 算法实质上是基于局部灰度匹配的算法,对于纹理信息缺乏的机载SAR影像,只可提取少量稳定的匹配点对,其正确率相对前两者较低。总体而言,在机载SAR影像中SIFT 算法能够提取到稳定的匹配点对,并结合基于2D单应变换的RANSAC算法,可有效剔除误匹配点对,提高匹配正确率及精度。     

InSAR在云南德钦县一中河泥石流物源汇集及失稳模式中的探究

针对传统方法难以定量描述大尺度泥石流形成机理的问题,提出一种联合SAR卫星影像相位信息和后向散射信息全面识别泥石流发育机制的方法,并使用该方法探究云南省德钦县一中河泥石流物源汇集及失稳模式.通过后向散射系数反演研究区土壤含水量的时空变化趋势,利用升降轨Sentinel-1 A数据获取坡表二维形变.结果表明,研究区土壤含...     

基于高斯曲线拟合-FFT方法的南海风场反演

海面风场是海洋学的基本参量,获取海面风场对了解海洋的物理过程以及海洋与大气之间的相互作用至关重要。宽阔的海域面积及复杂的海面状况通常使南海海面上的风场信息很难被及时获取。ENVISAT ASAR是一种全天候全天时监测海面的微波雷达传感器,可实时获取海面风场数据。本文基于已有ASAR数据对南海海面风场进行反演实验,首先将结合高斯曲线拟合的FFT风向反演方法应用于南海风向反演,并参考Cross-Calibrated Multi-Platform （CCMP）风场数据去除180o方向模糊获得海面风向。然后,将高斯曲线拟合-FFT风向与传统的峰值-FFT风向进行对比,最后将准确率较高的高斯曲线拟合-FFT风向分别输入CMOD4模型和CMOD5模型获得海面风速大小。实验结果与CCMP参考数据的比较结果表明,在风条纹不明显的情况下,利用结合高斯曲线的FFT风向反演方法和CMOD4模型风速反演方法可有效地进行南海海面风场反演。该成果对利用SAR数据实时获取南海大面积海面风场信息,尤其是观测点缺乏海域的风场信息,具有重要的指导意义。     

Variations of dissolved iron in the Amur River during an extreme flood event in 2013

As a key factor limiting primary productivity in marine ecosystem, dissolved iron(DFe) export from fluvial systems has increased recently. There is particular concern about discharges of DFe during extreme flooding, when they are thought to increase considerably. An extreme flood event that caused inundation of extensive areas of Far Eastern Russia and Northeastern China occurred in the basin of the Amur River during summer and autumn 2013. During this event, water samples were collected in the middle reaches of the Amur River and the lower reaches at Khabarovsk City and analyzed for DFe concentrations and other aquatic parameters. The results show that the average DFe concentrations in the middle reaches of the Amur River(right bank) and at Khabarovsk were 1.11 mg/L and 0.32 mg/L, respectively, during the extreme flood in 2013. The total discharge of DFe during the flood event was 6.25 × 104 t. The high discharge of DFe during the flood reflects the elevated discharge of the river, hydrologically connected riparian wetlands, vast quantities of terrestrial runoff, and flood discharges from the Zeya and Bureya reservoirs. These results show that long-term monitoring is needed to identify and assess the impacts of DFe transport on the downstream reaches, estuarine area, and coastal ecosystems of the Amur River.     

POSSIBLE HYDROGEOCHEMICAL PRECONDITIONS FOR KASHIN－BECK DISEASE IN TRANSBAIKALIA

ＰＯＳＳＩＢＬＥＨＹＤＲＯＧＥＯＣＨＥＭＩＣＡＬＰＲＥＣＯＮＤＩＴＩＯＮＳＦＯＲＫＡＳＨＩＮ－ＢＥＣＫＤＩＳＥＡＳＥＩＮＴＲＡＮＳＢＡＩＫＡＬＩＡ￥ＺａｍａｎａＬｅｏｎｉｄＶａｓｉｌｅｖｉｃｈ（ＣｈｉｔａＩｎｓｔｉｔｕｔｅｏｆＮａｔｕｒａｌＲｅｓｏｕ...     

STUDY ON THE SUSTAINABLE DEVELOPMENT OF WETLAND RESOURCES IN THE USSURI /WUSULI RIVER BASIN

1 INTRODUCTION The Ussuri / Wusuli River watershed is located in the southeast part of Heilongjiang Province of China, which joins remote regions of Russia. The watershed consists of approximately 26 000 000 ha, which is about two thirds of the watershed ecosystem in Russia, one  third in China. The Ussuri River forms part of the border between Russia and China, the shared border stretches more than 1100 km. Khanka/Xingkai Lake lies within both China and Russia. Its total area …     

Gold-Plationoid Mineralization of Metasomatically Altered Ultramafites in Precambrian Protrusions of Mamynsky Geoblok

On the contiguous territories of Russia and China, along the left and right banks of the Amur River (Heilongjiang Province of China, and Amur Oblast′ of Russia), several Precambrian protrusions (Gonzhinsk, Mamynsk, Amurkhe, and Khumakhe) are known. On the Russian territory, along the setting and on the area of the protrusions, lode manifestations, precious-metal deposits, and gold-platinoid placers are known having the industrial imponance. Ultramafites are metasomatically altered more likely by the action of the kate Paleozoic intrusions and produced by them hydrothermae, and are transformed into listvenites. It can be concluded that as one of the sources of precious metals in the placers were the aureoles of listvenitization. This is evidenced by the presence of talc (typomorphic mineral of apoultrabasites) inclusions together with Pt-, Pd- and Ir-bearing gold in the corrosive coatings of the primary platinoids. This conclusion requires the revision of the work strategy of prospecting the lode gold and PGE manifestations within the ore-placer node because apoultrabasites before were considered non-promising for precious metals.     

Gold-Platinoid Mineralization of Metasomatically Altered Ultramafites in Precambrian Protrusions of Mamynsky Geoblok

On the contiguous territories of Russia and Chi-na,along the left and right banks of the Amur Riv-er (Heilongjiang Province of China,and Amur Oblast' of Russia),among the Late Mesozoic ter-rigenous and volcano-plutonic formations,several Precambrian prot…     

Analysis of multi-dimensional SAR for determining the thickness of thin sea ice in the Bohai Sea

Flat thin ice (<30 cm thick) is a common ice type in the Bohai Sea, China. Ice thickness detection is important to offshore exploration and marine transport in winter. Synthetic aperture radar (SAR) can be used to acquire sea ice data in all weather conditions, and it is a useful tool for monitoring sea ice conditions. In this paper, we combine a multi-layered sea ice electromagnetic (EM) scattering model with a sea ice thermodynamic model to assess the determination of the thickness of flat thin ice in the Bohai Sea using SAR at different frequencies, polarization, and incidence angles. Our modeling studies suggest that co-polarization backscattering coefficients and the co-polarized ratio can be used to retrieve the thickness of flat thin ice from C- and X-band SAR, while the co-polarized correlation coefficient can be used to retrieve flat thin ice thickness from L-, C-, and X-band SAR. Importantly, small or moderate incidence angles should be chosen to avoid the effect of speckle noise.     

RESEARCH ON SYSTEM OF FLOOD DISASTER CONTROL AND REDUCTION SUPPORTED BY GIS IN MEDIUM AND SMALL BASINS

Southeast China coastal areas belong to subtropical monsoon climatic zone,thus easily affected by floods resulted from typhoons and rainstorm.Since the areas of river basins are small,rivers flood regulation capacities are low,and therefore flood hazard is grave.In the paper,taking the Yongjiang basin in southeast China as an example,the approaches and methods of geographic information system(GIS) applied to flood disaster control and reduction research on small basin are explred.On GIS help the rainfall-runoff calculation model and the river dchannel flood routing model are developed.And the evaluating flood submerged are and the damage assessment models are built supported by digit elevation models.Lastly the decision support system on GIS supported for flood control in research basin has been set up.This greatly improves flood-proofing decision-making capacities in river basin,and provides valuable information and a mode for flood prevention and reduction in the medium and small basin .Meanwhile,the research indicates that technologies of GIS provide a powerful tool for flood disaster control.     

中国陆表水空间展布及动态变化分析

陆表水是维持人类生存的重要资源之一,而中国是水资源严重匮乏的国家之一。因此,掌握中国陆表水的空间分布及其变化状况对合理利用水资源、提高人们节约用水意识等具有重要作用。利用全球首套空间分辨率为30m的全球地表覆盖数据(Globe Land30))中的2000年和2010年两期数据,首先采用重分类的方法提取出我国2000年和2010年的内陆地区水体数据,再根据我国的主要流域和等降水量线数据,统计出各流域及各降水区域的水域面积、水域率数据,并对其动态变化进行分析。结果表明,我国水资源分布不均,呈现明显的南多北少、东多西少的态势。从2000到2010年,我国的陆表水水域面积趋于减少,其中以长江流域水域面积的减少最为明显。     

SNOW COVER MONITORING BY REMOTE SENSING AND SNOWMELT RUNOFF CALCULATION IN THE UPPER HUANGHE RIVER BASIN

The upper Huanghe(Yellow) River basin is situated in the northeast of the Qinghai-Xizang(Tibet)Plateau of China.The melt-water from the snow-cover is main water supply for the rivers in the region during springtime and other arid regions of the northwestern China, and the hydrological conditions of the rivers are directly controlled by the snowmelt water in spring .So snowmelt runoff forecast has importance for hydropower,flood prevention and water resources utilize-tion.The application of remote sensing and Geographic Information System(GIS) techniques in snow cover monitoring and snowmelt runoff calculation in the upper Huanghe River basin are introduced amply in this paper.The key parame-ter-snow cover area can be computed by satellite images from multi-platform,multi-templral and multi-spectral.A clus-ter of snow-cover data can be yielded by means of the classification filter method.Meanwhile GIS will provide relevant information for obtaining the parameters and also for zoning .According to the typical samples extracting snow covered moun-tained in detail also.The runoff snowmelt models based on the snow-cover data from NOAA images and observation data of runoff,precipitation and air temperature have been satisfactorily used for predicting the inflow to the Longyangxia Reser-voir,which is located at lower end of snow cover region and is one of the largest reservoirs on the upper Huanghe River, during late March to early June.The result shows that remote sensing techniques combined with the ground meteorological and hydrological observation is of great potential in snowmelt runoff forecasting for a large river basin.With the develop-ment of remote sensing technique and the progress of the interpretation method,the forecast accuracy of snowmelt runoff will be improved in the near future .Large scale extent and few stations are two objective reality situations in Chian,so they should be considered in simulation and forecast.Apart from dividing ,the derivation of snow cover area from satellite images would decide the results of calculating runoff.Field investigation for selection of the learning samples of different snow patterns is basis for the classification.