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J. Amorós López E. Izquierdo VerdiguierL. Gómez Chova J. Muñoz MaríJ.Z. Rodríguez Barreiro G. Camps VallsJ. Calpe Maravilla 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(1):115-123
Managing land resources using remote sensing techniques is becoming a common practice. However, data analysis procedures should satisfy the high accuracy levels demanded by users (public or private companies and governments) in order to be extensively used. This paper presents a multi-stage classification scheme to update the citrus Geographical Information System (GIS) of the Comunidad Valenciana region (Spain). Spain is the first citrus fruit producer in Europe and the fourth in the world. In particular, citrus fruits represent 67% of the agricultural production in this region, with a total production of 4.24 million tons (campaign 2006-2007). The citrus GIS inventory, created in 2001, needs to be regularly updated in order to monitor changes quickly enough, and allow appropriate policy making and citrus production forecasting. Automatic methods are proposed in this work to facilitate this update, whose processing scheme is summarized as follows. First, an object-oriented feature extraction process is carried out for each cadastral parcel from very high spatial resolution aerial images (0.5 m). Next, several automatic classifiers (decision trees, artificial neural networks, and support vector machines) are trained and combined to improve the final classification accuracy. Finally, the citrus GIS is automatically updated if a high enough level of confidence, based on the agreement between classifiers, is achieved. This is the case for 85% of the parcels and accuracy results exceed 94%. The remaining parcels are classified by expert photo-interpreters in order to guarantee the high accuracy demanded by policy makers. 相似文献
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政务GIS平台专题网站的建设 总被引:1,自引:1,他引:0
以"中国(云南)一东盟自由贸易区一南亚区域合作联盟空间信息公共平台"中"云南省综合省情"专题为例,阐述政务GIS平台专题页面制作方法,从页面布局、信息组织、地图服务调用等方面对政务专题网站的建设进行探讨,着重介绍了页面中控制内容区对象的方法,并展望其应用前景,以期为政务GIS平台中相关功能的应用与开发提供参考. 相似文献
996.
Skillful streamflow forecasts at seasonal lead times may be useful to water managers seeking to provide reliable water supplies and maximize hydrosystem benefits. In this study, a class of data mining techniques, known as tree-structured models, is investigated to address the nonlinear dynamics of climate teleconnections and screen promising probabilistic streamflow forecast models for river–reservoir systems. In a case study of the Lower Colorado River system in central Texas, a number of potential predictors are evaluated for forecasting seasonal streamflow, including large-scale climate indices related to the El Niño–Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), and others. Results show that the tree-structured models can effectively capture the nonlinear features hidden in the data. Skill scores of probabilistic forecasts generated by both classification trees and logistic regression trees indicate that seasonal inflows throughout the system can be predicted with sufficient accuracy to improve water management, especially in the winter and spring seasons in central Texas. 相似文献
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Site specific probabilistic seismic hazard analysis at Dubai Creek on the west coast of UAE 总被引:2,自引:1,他引:1
Ayman A. Shama 《地震工程与工程振动(英文版)》2011,10(1):143-152
A probabilistic seismic hazard analysis (PSHA) was conducted to establish the hazard spectra for a site located at Dubai Creek on the west coast of the United Arab Emirates (UAE). The PSHA considered all the seismogenic sources that affect the site, including plate boundaries such as the Makran subduction zone, the Zagros fold-thrust region and the transition fault system between them; and local crustal faults in UAE. PSHA indicated that local faults dominate the hazard. The peak ground acceleration (PGA) for the 475-year return period spectrum is 0.17 g and 0.33 g for the 2,475-year return period spectrum. The hazard spectra are then employed to establish rock ground motions using the spectral matching technique. 相似文献
998.
Lisham Bonakdar 《Ocean Engineering》2011,38(1):111-118
Prediction of run-up level is a key task in design of the coastal structures. For the design of the crest level of coastal structures, the wave run-up level with a 2% exceedance probability, Ru2%, is most commonly used. In this study, the performance of M5 model tree for prediction of the wave run-up on rubble-mound structures was investigated. The main advantage of model trees, unlike the other soft computing tools, is their easier use and more importantly their understandable mathematical rules. Experimental data set of Van der Meer and Stam was used for developing model trees. The conventional governing parameters were selected as the input variables and the obtained results were compared with Van der Meer and Stam’s formula, recommended by the Coastal Engineering Manual (CEM, 2006). The predictive accuracy of the model tree approach was found to be superior to that of Van der Meer and Stam’s empirical formula. Furthermore, to judge the generalization capability of the model tree method, the model developed based on laboratory data set was validated with the prototype run-up measurements on the Zeebrugge breakwater, Belgium. Results show that the model tree is more accurate than empirical formulas and TS Fuzzy approach in estimating the full-scale run-up. 相似文献
999.
海洋发光弧菌是海水养殖中重要的条件致病菌。从福建省晋江市附近水产养殖场花蛤、牡蛎软组织及波罗地海大菱鲆肠道内含物中分离得到16 株发光细菌, 采用ARDRA(amplified ribosomal DNArestriction analysis)、16S rDNA 序列测定、Biolog 碳源代谢分析及药敏试验等方法对... 相似文献
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海洋新菌的分类与鉴定方法 总被引:2,自引:0,他引:2
细菌的分类鉴定与细菌的研究和应用有着同等重要的地位。目前从自然界中可以培养的细菌总量不到1%,大多数海洋细菌的分类鉴定仍需建立在纯培养基础上。本文对目前可培养海洋细菌的分类鉴定方法做了系统的综述,详述了系统发生树的构建,汇总了生理生化分类特征,概述了主要的遗传学分析方法,包括16S rDNA序列分析,G+C含量测定,DNA-DNA杂交,MLST(多位点序列分型,Multi Locus Sequence Typing)以及核酸指纹图谱等,并指出每种方法适用的范围以及应用时需要注意的事项。另外,本文还提出了新菌分类鉴定的一般步骤。文章最后对目前海洋细菌分类鉴定的发展趋势进行了总结和展望。 相似文献