顾及城区形态特征的太阳辐射传输模型及其遥感应用     

胡德勇  张亚妮  刘曼晴  于琛  曹诗颂  狄宇飞 《遥感学报》2021,25(10):2116-2126

准确量化地表太阳辐射量是反射率遥感反演之基础,开展城区表面辐射研究具有重要意义。本文选择天空视域因子（V）表征城区下垫面形态特征,并区分太阳直接辐射、天空漫辐射以及环境辐射的不同影响,构建了城区表面太阳辐射模型USSR（Urban Surface Solar Radiation）;然后,以Landsat 8可见光和近红外波段遥感数据为例,分析了USSR模型对于量化城区表面太阳辐射的应用前景。研究结论为：（1）USSR模型以天空视域因子为核心要素,清楚量化了城区表面各辐射分量,有效模拟了城区表面太阳辐射传输过程,能够较好地表达城区下垫面形态结构对入射辐射的影响;（2）将USSR模型应用于Landsat 8遥感数据可见光和近红外波段时,基于USSR模型估算得到的城区表面太阳辐射,与不考虑下垫面形态特征影响相比,前者可以较好地表达城区下垫面对入射辐射的“截留”作用;（3）USSR模型估算结果与TEB模型相比,二者具有较高的相关性,间接验证了USSR模型的可用性;（4）对USSR模型的V和下垫面反射率两变量进行敏感性分析,显示随着V值的增加,结果呈递增趋势;通常情况下的地表反射参数P设置值,相对于参数V的影响要弱,呈现不敏感性。本文提出的USSR模型可订正城区表面太阳辐射值,从而拓展城市遥感的应用深度和广度。  相似文献   

Geometric calculation of view factors for stream surface radiation modelling in the presence of riparian forest          下载免费PDF全文

R. D. Moore  J. A. Leach  J. M. Knudson 《水文研究》2014,28(6):2975-2986

Many efforts to model stream temperature by using an energy budget approach have not accounted for view factors in modelling stream surface radiative exchanges, used informal approaches for computing them, or relied on calibration, which is not applicable for prediction at unmonitored sites or for predicting the effects of changes in riparian vegetation. In this paper, equations are derived for calculating view factors on the basis of geometric considerations for streams with and without riparian forest. The solutions can accommodate vegetation overhanging the stream surface. Example calculations illustrate the substantial variability of view factors across the stream width, which has implications for the estimation of view factors from point‐scale radiation measurements over the stream surface, and the important influence of overhanging vegetation on view factors for narrow streams. View factors computed from the geometric model agreed well with view factors computed from hemispherical photography for streams ranging from 1 to almost 50 m wide, indicating that the model appears to be reasonably robust to deviations from the simplified geometry assumed by the model. In addition to their use in modelling stream surface energy exchanges, the solutions could also be adapted for application to energy balance and microclimate modelling in linear forest openings, such as seismic lines used in oil and gas exploration. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

沙地水分动力学研究新视角   总被引：11，自引：5，他引：11  

刘元波  高前兆 《中国沙漠》1997,17(1):95-98

沙地水分研究正从形态学观点向能态观点转变，本章简述了沙地水分动力学主要研究内容和研究动态，指出当前研究中存在的问题并作了展望  相似文献   

有云时大气红外遥感及其反演问题 I. 理论研究          下载免费PDF全文

李俊  曾庆存 《大气科学》1997,21(3):341-347

我们已经研究了晴空情况下的大气红外遥感及其反演问题。本文对有云情况下的大气红外遥感及其反演问题进行了研究，首先指出国际上通用的处理有云反演的晴空订正法存在误差放大问题，然后提出了3×3相邻视场同步反演法，在该方法中，假定3×3相邻视场具有共同的大气温度廓线和大气水汽廓线，从而使求解方程数增加到9倍，而反演参数只增加有限的几个，大大提高了有云情况下反演的稳定性。  相似文献   

Econometric analysis on the effect of port state control inspections on the probability of casualty: Can targeting of substandard ships for inspections be improved?     

Sabine Knapp  Philip Hans Franses 《Marine Policy》2007

This article is based on 183,819 port state control inspections from various port state control regimes and casualties from three different data sources for a time period of 6 years. It is the first time an analysis on a combined dataset of this magnitude has been performed. Binary logistic regression is used to measure the effect of inspections on the probability of casualty, which can be measured for very serious casualties but not for serious or less serious casualties. In addition, the magnitude of improvement areas for targeting substandard vessels is determined and the models further show how targeting of substandard ships on a combined dataset can be improved. In addition, the analysis also compares the fishing fleet with the commercial fleet.  相似文献   

Foreshore and seabed policy: A Māori perspective     

Angeline Greensill 《New Zealand geographer》2005,61(2):158-160

Abstract: The comment provides a Māori perspective on the Foreshore and Seabed Act. In contrast to the western view, Māoris understand their relationship with the coast in ways that are holistic, intertwined and unbounded. The Act disrupts the wairua or spirit of place, impacting on relationships that have been nurtured by whānau and hapū over time.  相似文献   

对地震预报的看法和建议     

朱之华 《国际地震动态》1998,(5):13-15

文章对当前地震预报工作中存在的一些难点和问题进行了分析,提出了对地震预报和防震减灾工作的一些看法和建议。  相似文献   

Mechanisms controlling the air–sea flux in the North Sea     

A.E.F. Prowe  Helmuth Thomas  Johannes Ptsch  Wilfried Kühn  Yann Bozec  Laure-Sophie Schiettecatte  Alberto V. Borges  Hein J.W. de Baar 《Continental Shelf Research》2009,29(15):1801-1808

The mechanisms driving the air–sea exchange of carbon dioxide (CO₂) in the North Sea are investigated using the three-dimensional coupled physical–biogeochemical model ECOHAM (ECOlogical-model, HAMburg). We validate our simulations using field data for the years 2001–2002 and identify the controls of the air–sea CO₂ flux for two locations representative for the North Sea's biogeochemical provinces. In the seasonally stratified northern region, net CO₂ uptake is high () due to high net community production (NCP) in the surface water. Overflow production releasing semi-labile dissolved organic carbon needs to be considered for a realistic simulation of the low dissolved inorganic carbon (DIC) concentrations observed during summer. This biologically driven carbon drawdown outcompetes the temperature-driven rise in CO₂ partial pressure (pCO₂) during the productive season. In contrast, the permanently mixed southern region is a weak net CO₂ source (). NCP is generally low except for the spring bloom because remineralization parallels primary production. Here, the pCO₂ appears to be controlled by temperature.  相似文献   

中国大地构造研究之思考——中国地质学家的责任与担当   总被引：1，自引：1，他引：0       下载免费PDF全文

任纪舜  赵磊  李崇  朱俊宾  肖黎微 《中国地质》2017,44(1):33-43

19世纪中叶到20世纪中叶盛行的地槽-地台学说,起源于西方学者对大西洋半球的欧洲和北美东部地质的研究。20世纪中叶提出的板块构造学说,虽然起源于对现代海洋的地质、地球物理调查,但用板块学说解释大陆构造的尝试,也是从解剖北美和欧洲大西洋两岸的古生代造山带开始的。二者均缺少太平洋半球的亚洲,特别是中国及邻区的资料基础,因此,其立论基础是不全面的。这就给亚洲,特别是给中国学者提供了很大的发展空间。通过1∶500万国际亚洲地质图的编制和全球构造的对比研究,笔者发现,处于亚洲核心地带的中国及邻区不仅是亚洲也是全球显生宙地质结构和发展历史最复杂的地区。古亚洲洋构造域的乌拉尔—蒙古—兴安巨型造山带是全球规模最大、发育历史最长、地质结构最复杂的古生代造山带;中国西南部,特别是青藏高原是全球特提斯巨型造山带出露宽度最大、地质纪录保存最完整的地段;中国东部的太平洋构造域,既有亚洲东缘的巨型中生代造山带和新生代的沟弧盆体系,又有宽阔的滨太平洋陆缘活化带。这就使中国及邻区成为研究全球显生宙构造不可缺少的重要地段。我们一定要抓住中国在全球构造研究中的区位优势,以地球系统多层圈构造观为指导,用地质、地球物理、地球化学多学科结合的方法,立足实际,抓住特色,构建中国大地构造的新理论、新模型,为国际地球科学,为发展、完善现代大地构造学理论做出应有的贡献!  相似文献   

Monte Carlo simulation of an in-situ search of water on the Martian surface by using neutron spectroscopy     

H Vincke  W NinausHj Müller  J Brückner 《Planetary and Space Science》2003,51(6):375-380

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