近岸水体异源遥感反射率产品的融合方法研究     

张翼飞  朱建华  田震  贾迪  高飞 《海洋通报》2022,(4):361-370

数据融合能够综合利用多源遥感数据优势,获取高空间分辨率和高测量精度的遥感影像,对于近岸水体生态环境监测和灾害预警均具有重要意义。但目前使用的数据融合方法多是针对内陆水体或大洋水体的,其在近岸水体的适用性仍需进一步评估,因而本文开展了近岸水体遥感数据融合方法的对比研究。本文以高空间分辨率的Sentinel-2 MSI影像和中等空间分辨率的Sentinel-3 OLCI影像为数据源,分别开展了基于小波变换（WTBF）、生物光学模型（BOBF）和混合像元分解（IUBF）三种方法的数据融合实验,并在此基础上借助现场实测遥感反射率（Remote-sensing Reflectance,Rrs）数据与融合影像对应点的平均相对误差（MRE）、均方根误差（RMSE）、偏差（bias）和平均梯度对各种方法的融合数据质量和区域适用性进行了评估。结果表明：（1） OLCI的Rrs数据精度高于MSI。其中MSI在443 nm、560 nm和665 nm三个波段的MRE、RMSE均高于OLCI,表明MSI的Rrs精度相对OLCI较低;目视效果和平均梯度表明MSI的清晰度高于OLCI。（2） BOBF是三种方法中...  相似文献   

Genesis of Kaolinite Deposits in the Jungar Coalfield,NorthChina: Petrological,Mineralogical and Geochemical Evidence     

LIU Linsong  ZHANG Tongjun  LIU Jianping  LIU Qinfu  LI Kuo  LIU Di  LIU Wanyue 《《地质学报》英文版》2021,95(2):517-530

Petrological, mineralogical and geochemical studies carried out on kaolinite deposits in Haerwusu surface mine,Jungar Coalfield, northern Ordos Basin, North China, define their characteristics, ore genesis and economic interest. Based on the crystalline size, two different types of kaolinite rocks, cryptocrystalline and grainy, were identified under the microscope. XRD data show that kaolinite is the predominant mineral, associated with boehmite, magnesite, anatase, pyrite,diaspore and calcite. However, high boehmite content(mean 70%) shows up in the middle layers. Kaolinite minerals present homogeneous shape and a good crystallinity(HI = 0.96–1.26). Geochemical studies show that the SiO2/Al2 O3 molar ratio of kaolinite is close to the theoretical value, and the contents of Na2 O, K2 O, CaO, MgO are less, suggesting a strong chemical weathering environment. The REE and Eu anomalies show a close relationship between kaolinite and the Yinshan Oldland granite. A Ce anomaly reflects a continental sedimentary environment with shallow water. A temperature range of26.7–34℃ was calculated on the basis of the isotopic signatures(δ18 O, δD) of the kaolinite rocks. All these data indicate that the formation of the kaolinite is caused mainly by the dissolution, coagulation, precipitation and recrystallization of aluminosilicate clastics in acidic conditions. The formation of boehmite in the middle layers indicates that the source rocks have changed. Boehmite is mainly formed by dehydration and compaction of an aluminum-rich colloid which transported into peat swamp during diagenesis. In addition, it formed by desiliconization of kaolinite under acidic conditions. Due to its high kaolinite content(up to 90%) and low iron mineral content(less than 1%), and good crystallinity, kaolinite deposits occurred at Haerwusu surface mine probably have great economical value in the future.  相似文献   

理想模拟的温带气旋中冷暖输送带特征分析     

王迪  张熠  储可宽  王新敏 《大气科学》2022,46(2):346-358

本文利用WRF理想斜压波模式模拟了理想湿大气中温带气旋的快速发展过程,采用拉格朗日轨迹筛选方法识别了气旋内部冷、暖输送带结构,分析了沿着输送带轨迹的物理量演变特征,探究了输送带气流对气旋降水结构的影响。本文在再现前人研究结论的基础上,发现了更精细的输送带结构特征,尤其是对冷输送带特征有了进一步认识。研究表明,根据相对气旋中心运动特征可将暖输送带划分为“前倾上升”和“后倾上升”两支。两支气流均起始于对流层低层冷锋前暖区内,旋转上升到对流层中高层出流区后分别向气旋中心的下游和上游运动,并在中高层产生负位涡扰动,促进高空系统发展。同时,暖输送带向上层输送水汽,影响锋面附近降水中心的形成和维持。在对冷输送带的研究中,本文证实了前人研究描述的上升类和低层运动类特征,而且发现其可以更精细地呈现出四支气流结构。“前倾上升”和“后倾上升”两支气流的初始位置靠近暖锋,上升运动到对流层中层后分别向气旋中心的下游和上游运动,利于促进暖锋附近降水形成;而“环气旋前倾”和“环气旋后倾”两支气流始终在对流层低层运动,初始远离暖锋朝向气旋中心运动,水汽含量增加,随后环绕气旋中心缓慢上升运动到气旋西侧后分别向气旋下游...  相似文献   

煤矸石的环境危害及综合利用研究   总被引：26，自引：0，他引：26       下载免费PDF全文

刘迪 《气象与环境学报》2006,22(3):60-62

针对我国矿区煤矸石大量排放的现状,介绍了煤矸石的形成以及煤矸石大量堆放对环境所产生的危害和影响,并概述了煤矸石污染的防治措施及其综合利用途径。  相似文献   

基于反射峰面积的水体叶绿素遥感反演模拟研究   总被引：1，自引：0，他引：1  

马万栋  王桥  吴传庆  殷守敬  邢前国  朱利  吴迪 《地球信息科学学报》2014,16(6):965-970

叶绿素浓度是水体富营养化状态的重要指标,也是水色遥感反演的水质参数之一。水体中叶绿素浓度的遥感反演主要是建立实测光谱和实测水质参数二者之间的关系模型,利用遥感影像进行叶绿素浓度的信息提取。传统的叶绿素浓度遥感反演受区域性和季节性的影响,反演精度不高,而且反演模型不具普适性,需对叶绿素光谱特征进行分析,建立高精度的反演模型。本文采用Hydrolight数据模拟了不同叶绿素浓度(1~200 µg·L^-1)的水体在可见光近红外的反射波谱曲线,通过分析叶绿素的光谱特征选取了特征波段或波段组合,并建立了叶绿素浓度反演模型。研究表明,除反射峰波长模型外,反射峰面积模型、三波段模型、红光线高度模型等均能较好地反演叶绿素浓度。在不同叶绿素反演模型中,除红光线模型外,最优的是反射峰面积模型,其决定系数为0.9689,反演误差为25.25 µg·L^-1;其次是三波段模型,其决定系数为0.9637,反演误差为10.66 µg·L^-1。究其原因,三波段模型考虑了水体中非色素悬浮物、黄色物质及水体后向散射对叶绿素浓度反演造成的影响;反射峰面积模型除此之外还综合考虑了叶绿素散射效率的影响。  相似文献   

空间综合人文学与社会科学研究综述     

秦昆  林珲  胡迪  许刚  张晓祥  卢宾宾  叶信岳 《地球信息科学学报》2020,22(5):912-928

地理信息科学与哲学、历史、文学、艺术、社会学、经济学、政治学、管理学等人文学与社会科学进行了全面的深度融合。一方面,地理信息科学领域的学者积极拓展研究领域,为人文学与社会科学领域的学者提供空间化、可视化的技术手段;另一方面,人文学与社会科学领域的学者积极学习和掌握地理信息技术,在研究中积极引入空间思维和空间可视化方法。同时,一些适用于人文学与社会科学研究者的开放平台、代码和工具不断涌现。本文在对空间综合人文学与社会科学的最新进展进行全面总结的基础上,探讨了空间人文学与社会科学研究的思路和框架,并分别对该框架各分支的研究进展进行了梳理和评述,包括：历史GIS,文学GIS,语言学GIS,GIS与哲学、人类动力学、人文地理学等;以及GIS与政治学及国际关系学,GIS与管理学、空间计量经济学、社会地理计算、空间社会网络与空间交互网络、犯罪地理学、健康地理与公共卫生学等。接着,本文对空间综合人文学与社会科学的研究方法进行了分析,包括：空间思维与空间计量、认知心理学与空间认知、空间可视化与虚拟地理分析、平台研发等。最后,对空间综合人文学与社会科学研究的关键问题和未来发展方向进行了展望。  相似文献   

Evaluation of potential productivity of woody energy crops on marginal land in China     

Jinzhu Wang  Ming Gao  Xinhua He  Qian Zhang  Natamba Leo  Chang Xu 《中国地理科学(英文版)》2017,27(6):963-973

Energy crops are a basic material in the bioenergy industry, and they can also mitigate carbon emissions and have environmental benefits when planted on marginal lands. The aim of this study was to evaluate the potential productivity of energy crops on marginal lands in China. A mechanistic model, combined with energy crop and land use characteristics, and meteorological and soil parameters, was used to simulate the potential productivity of energy crops. There were three main results. 1) The total marginal land in China was determined to be 104.78 × 10~6 ha. The 400-mm precipitation boundary line, which is the dividing line between the semi-humid and semi-arid zones in China, also divided the marginal land into shrub land and sparse forest land in the southeast and bare land, bare rock land, and saline alkali land in the northeast. 2) The total area of the marginal land suitable for planting energy crops was determined to be 55.82 × 10~6 ha, with Xanthoceras sorbifolia and Cerasus humilis mainly grown in the northern China, Jatropha curcas and Cornus wilsoniana mainly grown in the southwest and southeast, and Pistacia chinensis mainly grown in the central area, while also having a northeast-southwest zonal distribution. 3) Taking the highest yield in overlapping areas, the potential productivity of target energy crops was determined to be 32.63 × 10~6 t/yr. Without considering the overlapping areas, the potential productivity was 6.81 × 10~6 t/yr from X. sorbifolia, 8.86 × 10~6 t/yr from C. humilis, 7.18 × 10~6 t/yr from J. curcas, 9.55 × 10~6 t/yr from P. chinensis, and 7.78 × 10~6 t/yr from C. wilsoniana.  相似文献   

Pre-summer Persistent Heavy Rain over Southern China and Its Relationship with Intra-seasonal Oscillation of Tropical Atmosphere     

邱迪  姚素香  夏依聪 《热带气象学报(英文版)》2022,28(4):445-456

Based on daily precipitation data supplied by the Chinese meteorological administration, hourly reanalysis datasets provided by the ECMWF and daily outgoing long wave radiation supplied by the NOAA, the evolution regularity of continuous heavy precipitation over Southern China(SC) from April to June in 1979-2020 was systematically analyzed. The interaction between specific humidity and circulation field at the background-scale, the intra-seasonal-scale and the synoptic-scale, and its influence o...  相似文献   

青藏高原雨季降水的水汽条件研究   总被引：2，自引：2，他引：0  

段丽君  申红艳  余迪  马有绚  白文蓉  李万志 《冰川冻土》2021,43(4):939-947

利用1961—2017年青藏高原109站降水量资料、NCEP全球逐月再分析资料,讨论了雨季期间高原的水汽输送特征.结果表明:高原雨季降水呈显著的年际变化特征,高原雨季降水主模态为南北反向型和全区一致型.气候态高原雨季的水汽输送路径为来自阿拉伯海的偏西风水汽输送,在孟加拉湾附近分为三支水汽输送气流:一支向北输送,自高原南...  相似文献   

吉林省靖宇地区新太古代花岗闪长岩成因及地质意义     

韩迪  盘晓东  徐智涛  曹戎机  李忠伟  孙景贵  王抒 《地震地磁观测与研究》2021,42(2):149-150

研究区位于华北克拉通北缘东段吉林省南部靖宇县龙岗火山区(吴福元等,2014),距敦化—密山深大断裂东南侧约50 km.研究区内出露地层主要为第四纪粗面玄武岩及太古界花岗质片麻岩类,前寒武纪侵入体主要为中—细粒花岗闪长岩及细晶闪长岩.为了揭示研究区内新太古代花岗闪长岩成岩时代、岩石成因及地质意义,依托相关地质调查项目,在...  相似文献