应用遥感信息分析广西红树林动态变化特征

利用ENVI图像处理软件对广西沿海红树林的5个时相遥感数据和图像进行处理、分析并进行解译,通过对比分析,研究广西红树林在时空上的演变情况并分析其演变原因.结果得出,广西红树林在时空上的演化趋势是：1955年至1988年呈衰减的趋势,共减少4679.79hm^2,平均每年减少141.81hm^2;1988年至2004年呈递增趋势,共增加2395.05hm^2,平均每年增加149.69hm^2.变化的原因主要是人为因素影响,人们为了造地与围海养殖,砍伐红树林,使红树林面积迅速衰减;在无人为破坏的时候,红树林依靠自身的生长能力,能迅速生长,尤其是在海水富营养化的地段能恢复得很快.     

深圳湾近30年主要景观类型之演变

将深圳特区城市化过程划分为城市化初期、发展期、加速期和后期4个阶段,借助不同时期的遥感图像,包括1979年的MSS,1989、1998、2003、2009的TM,采用景观分类、景观转移和景观指数分析等一系列技术方法,分析了深圳湾地区基围、红树林和滩涂3种湿地景观类型的动态特征变化。结果表明:①深圳湾景观类型丰富,有较高多样性,但不同类型所占面积差异较大。人为干扰是深圳湾景观格局和景观类型发生改变的主要因素,围垦填海和城市建设严重破坏了深圳湾滨海湿地,海岸线不断向浅海延伸。②从1979年至2009年的30年间,研究区的城市建成区面积从508.95 hm2增加到2 072.52 hm2,最大斑块面积指数从2.94%增加到17.55%;③基围景观受人为干扰最严重,其面积在城市化初期表现为增长的趋势,1989年在景观中所占的比例达到了最高峰时的7.72%,此后城市化速度的加快使得基围景观逐渐演变为建成区或其他景观类型,且斑块形状趋于规则,由非正方形的形状趋于偏向正方形。在城市化的后两个阶段,基围景观发生转入和转出的斑块数量都很少,主要分布在进行了几次大规模围海工程的南山区;④城市化的前两个阶段红树林总面积持续减少,1998年后开始恢复增长,面积由52.65 hm2增加到2009年的81 hm2。景观指数分析表明,红树林景观没有趋于破碎化,反而形成了较大的景观斑块,景观连通性增加,保护区的建立对红树林的保护起着重要作用;⑤滩涂景观在过去30年间呈现较大幅度的波动和反复性,总的来说,面积从1979年的634.5 hm2减少至2009年的377.28 hm2,景观趋于破碎化,稳定性下降。     

基于遥感影像的深圳湾填海造地的初步研究

以1977年到2000年24年期间的8个时段的Landsat MSS/TM/ETM 影像为数据源,在遥感分析处理软件Erdas Image的支撑下,对深圳湾填海造地问题进行了研究．研究表明,20世纪90年代中期以前,深圳湾填海造地规模不大,表现出“小分散”的特点;大规模的填海造地发生在20世纪90年代中期以后,表现出“大成片”的特征,集中分布在后海西岸与红树林鸟类自然保护区以西的地区．填海区土地利用类型主要为对外交通用地、工业用地、商业用地、居住用地、道路用地等．填海造地还在继续进行．     

基于图谱分析钦州市市辖区湿地动态变化

【目的】研究钦州市市辖区湿地动态变化情况,探明湿地变化速度和原因,为地学信息图谱在湿地动态变化研究提供典型案例和实证。【方法】根据钦州市市辖区1990年、2000年和2010年的TM遥感影像,采用人工解译法和谱间关系法提取钦州市市辖区湿地类型空间分布信息,并应用地学信息图谱分析方法进行湿地动态变化分析。【结果】(1)1990~2010年钦州市市辖区河流、湖泊水库面积分别减少958.52hm2、1718.93hm,主要转变为非湿地、虾塘;(2)1990~2010年虾塘面积增加4557.87hm2,主要由非湿地、河流等类型转入;(3)1990~2000年红树林面积增加468.51hm2,主要由非湿地、河流转入,2000~2010年面积减少104.67hm2,主要转变为非湿地、虾塘;(4)1990~2000年水田面积增加1506.98hm2,2000~2010年面积减少1226.89hm2。【结论】钦州市市辖区湿地保护的比较好,呈增长趋势。     

红树林空间分布遥感监测精度的影响因素及应对措施Symbol

为提高红树林空间分布遥感监测结果的准确性和可靠性,分析了现有研究中存在的突出问题及其原因:不同研究者得到的同一区域和相同(或相近)年度的红树林面积相差很大; 同一研究者得到的同一区域相邻监测期的红树林面积变化剧烈,明显不符合红树林空间演变规律。结合长期监测实践,讨论了影响区域和地方尺度红树林空间分布遥感监测精度主要因素。分析认为:遥感图像的空间分辨率、海水淹没情况、信息提取策略、实地调查验证等是影响红树林空间分布遥感监测精度的主要因素。我国区域和地方尺度红树林空间分布遥感信息提取宜采用优于1 m、处于低潮位、滩涂裸露的高分辨率遥感数据; 在作多期遥感信息提取时,须确保相邻监测期间红树林斑块范围的变化符合其空间演变规律; 必须开展深入细致的地面调查工作,全面了解各个海湾的红树林分布状况和特点,并在实地逐一修正红树林斑块边界。     

基于邻域平滑稀疏模型的遥感图像红树林识别算法

传统遥感图像识别算法大多数依据地物的光谱特征,由于红树林这类遥感图像存在大量的"同物异谱"和"异物同谱"的现象,因此仅仅依靠光谱特征很难进行准确的识别。该文充分考虑红树林的地理特征和图像特征,提出了一种多特征融合的稀疏表示识别算法。实验结果表明,该算法能够提高红树林目标检测的效果。     

红树林空间分布遥感监测精度的影响因素及应对措施

为提高红树林空间分布遥感监测结果的准确性和可靠性,分析了现有研究中存在的突出问题及其原因:不同研究者得到的同一区域和相同(或相近)年度的红树林面积相差很大;同一研究者得到的同一区域相邻监测期的红树林面积变化剧烈,明显不符合红树林空间演变规律。结合长期监测实践,讨论了影响区域和地方尺度红树林空间分布遥感监测精度主要因素。分析认为:遥感图像的空间分辨率、海水淹没情况、信息提取策略、实地调查验证等是影响红树林空间分布遥感监测精度的主要因素。我国区域和地方尺度红树林空间分布遥感信息提取宜采用优于1 m、处于低潮位、滩涂裸露的高分辨率遥感数据;在作多期遥感信息提取时,须确保相邻监测期间红树林斑块范围的变化符合其空间演变规律;必须开展深入细致的地面调查工作,全面了解各个海湾的红树林分布状况和特点,并在实地逐一修正红树林斑块边界。     

福建九龙江口红树林变化的遥感监测

将LANDSAT MSS/TM/ETM数据与中国环境与灾害监测预报小卫星(HJ-1A/B)数据相结合,同时融合光谱信息、地学特征、纹理特征等多种信息,利用最大似然分类方法,提取了以福建省九龙江口红树林省级自然保护区为重点的九龙江口从20世纪70年代至2010年近40年间红树林面积的变化信息.结果表明九龙江口红树林面积在近40年呈现出减少(20世纪70-80年代)、缓慢增加(20世纪80-90年代)以及大幅度增长(2000年以后)3个主要阶段.其中人为活动(围垦、人工造林等)是九龙江口红树林面积大幅震荡的关键因子.     

广西红树林演化史与研究历程

红树林至少于7 000万年前诞生在地球上,在大约6 000年前的冰后期之后的某段时期才定居在我国的沿海滩涂上。清代人口大规模南迁,广西沿海的红树林因围海造田而开始遭到大规模破坏。20世纪80年代末广西留存海堤498个,其中的455个修建于1949年之前。全国调查数据表明,1980—2000年广西沿海虾塘建设侵占了1 464.1hm~2红树林;1986—2008年广西有166个新虾塘毁灭红树林438.91hm~2。在面积方面,1840年左右广西有红树林约24 065.8hm~2;1949年约10 856.6hm~2;2013年7 243.15hm~2,其中北海市3 263.66hm~2、钦州市2 097.41hm~2、防城港市1 882.07hm~2。广西红树林科学研究走过了1980—1990年的起始阶段,1991—2000年的积累阶段,2001—2010年的快速发展阶段及2011年以来的生态工程应用攻坚阶段。广西经历了21世纪头十年的红树林国际合作黄金期,培养了人才,提高了能力,促进了管理,显著提升了影响力。     

遥感技术在受损红树林资源调查与监测中的应用

红树林目前还受到不可持续利用方式的严重威胁。为快速掌握广西北海市合浦县铁山港白沙镇榄根村近岸海域监测范围内红树林受损及其周边景观演变情况,采用无人机（UAV）技术和多时期高分辨率卫星影像,结合野外地面群落调查,利用目视解译方法,对榄根村近岸海域红树林及周边景观进行遥感监测与分析。结果显示,该区域红树林2017年12月、2018年10月、2019年6月、2020年4月受损面积分别为0.55,4.77,9.42,17.18 hm²,4年间红树林受损面积增长约30.23倍。将2020年4月红树林受损区按照受损程度不同分为死亡区和严重受损区,面积分别为7.81,9.37 hm²,斑块数分别为35,106个。研究期内榄根村红树林受损面积呈迅速增加趋势,主要位于潮沟两侧;死亡及严重退化区红树林群落形态上呈灰白色不规则斑块状;红树林受损斑块呈“多点开花”特点,有从斑块林缘向内部蔓延的趋势。遥感技术可有效提高红树林生态监测的工作效率和准确性,应用前景广阔。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.