国内外海上风电机组基础结构设计标准浅析          下载免费PDF全文

孙文  刘超  张平  张积乐  黄维平 《海洋工程》2014,32(6):128-136

对国内外海上风电机组基础结构设计规范和相关标准进行了对比研究,结合我国海上风电机组基础结构设计开发中遇到的问题,论述海上风电机组基础结构设计中关于安全理念和设计荷载的设计方法和标准;分析对比各国规范对海上风电机组基础结构设计的推荐做法,剖析各国规范的设计理念和方法;比较海上风电机组基础结构与海洋石油平台在设计理念和设计标准方面的异同,并根据海上风电和海洋油气的行业特点,分析海上风电机组基础结构设计规范和海洋石油平台设计规范对于海上风电机组基础结构设计的适用性。在此基础上,基于我国海洋工程技术和海上风电产业的发展水平,提出发展我国海上风电机组基础结构的设计建议,指出我国海上风电开发中应注意和避免发生的问题。  相似文献   

Policy support,social capital,and farmers’ adaptation to drought in China     

《Global Environmental Change》2014

Increasingly severe drought has not only threatened food security but also resulted in massive socio-economic losses. In the face of increasingly serious drought conditions, the question of how to mitigate its impacts through appropriate measures has received great attention. The overall goal of this study is to examine the influence of policies and social capital on farmers’ decisions to adopt adaptation measures against drought. The study is based on a large-scale household and village survey conducted in six provinces nationwide. The survey results show that 86% of rural households have taken adaptive measures to protect crop production against drought, most of which are non-engineering measures. In the case of non-engineering measures, changing agricultural production inputs and adjusting seeding or harvesting dates are two popular options. A multivariate regression analysis reveals that government policy support against drought such as releasing early warning information and post-disaster services, technical assistance, financial and physical supports have significantly improved farmers’ ability to adapt to drought. However, since only 5% of villages benefited from such supports, the government in China still has significant room to implement these assistances. Moreover, having a higher level of social capital in a farm household significantly increases their adaptation capacity against drought. Therefore, the government should pay particular attention to the farming communities, and farmers within a community who have a low level of social capital. Finally, farmers’ ability to adapt to drought is also associated with the characteristics of their households and local communities. The results of this study also have implications for national adaptation plans for agriculture under climate change in other developing countries.  相似文献   

城乡建设用地增减挂钩项目审核审批系统开发     

张轶  季民  翟雪奎  刘允鹏 《测绘与空间地理信息》2013,(10):179-181,184

城乡建设用地增减挂钩项目审核审批系统是山东省国土资源部门开展城乡建设用地增减挂钩试点工作的重要组成部分。由于增减挂钩项目从材料申报到竣工验收涉及到的材料、审核意见等数据信息量巨大,为使审核审批过程中的工作更具有层次性与条理性,根据项目需求分析开发了本增减挂钩项目审批审核系统。本文主要对系统的开发环境、系统设计及实现进行了阐述。  相似文献   

GIS- and RS-based spatial decision support: structure of a spatial environmental information system (SEIS)     

《International Journal of Digital Earth》2013,6(2):134-154

Abstract

The development of spatial decision support for environmental resource management, e.g. forest and agroecosystem management, biodiversity conservation, or hydrological planning, started in the 1980s and was the focus of many research groups in the 1990s. The combined availability of spatial data and communication, computing, positioning, geographic information system (GIS)- and remote sensing (RS)-technologies has been responsible for the implementation of complex SDSS since the late 1990s. The regional GIS-based modelling of environmental resources, and therefore ecosystems in general, requires setting-up an extensive geo and model database. Spatial data on topography, soil, climate, land use, hydrology, flora, fauna and anthropogenic activities have to be available. Therefore, GIS- and RS-technologies are of central importance for spatial data handling and analysis. In this context, the structure of spatial environmental information systems (SEIS) is introduced. In SEIS, the input data for environmental resource management are organised in at least seven sub-information systems: base geodata information system (BGDIS), climate information system (CIS), soil information system (SIS), land use information system (LUIS), hydrological information system (HIS), spatial/temporal biodiversity information system (STBIS), forest/agricultural management information system (FAMIS). The major tasks of a SEIS are to (i) provide environmental resource information on a regional level, (ii) analyse the impact of anthropogenic activities and (iii) simulate scenarios of different impacts.  相似文献   

Spatial risk assessment of opium poppy cultivation in Afghanistan: integrating environmental and socio-economic drivers     

《International Journal of Digital Earth》2013,6(7):719-736

ABSTRACT

Recently the cultivation of opium poppy in Afghanistan reached unprecedented levels. It is agreed that the complex and coupled interactions of social, economic and environmental drivers are crucial for understanding the spatial and temporal dynamics of opium poppy cultivation in Afghanistan. In this context, we present an integrated risk concept, which considers environmental and socio-economic drivers of opium poppy cultivation. A set of spatially explicit indicators for the environmental suitability and socio-economic vulnerability was established and populated from a variety of databases. Subsequently, novel methods of modelling homogeneous and spatially explicit regions of opium poppy cultivation suitability, socio-economic vulnerability and risk are developed and applied. The risk assessment results demonstrate the complex nature of the illicit crops production in Afghanistan and prompt a more profound examination of the drivers of opium poppy cultivation in a spatial context. The study also confirms what has already been widely discussed in literature: that reasons for cultivation are spatially diverse and often distinct, meaning that any formulation of generalized explanations cannot be drawn without ignoring a more complex reality. Thus, an integrative spatial view of risk, which integrates the social dimension as well as environmental parameters, is required to better identify context-specific intervention measures.  相似文献   

A comparative assessment between object and pixel-based classification approaches for land use/land cover mapping using SPOT 5 imagery     

Mahyat Shafapour Tehrany  Mustafa Neamah Jebuv 《国际地球制图》2013,28(4):351-369

Abstract

Land use/land cover (LULC) classification with high accuracy is necessary, especially in eco-environment research, urban planning, vegetation condition study and soil management. Over the last decade a number of classification algorithms have been developed for the analysis of remotely sensed data. The most notable algorithms are the object-oriented K-Nearest Neighbour (K-NN), Support Vector Machines (SVMs) and the Decision Trees (DTs) amongst many others. In this study, LULC types of Selangor area were analyzed on the basis of the classification results acquired using the pixel-based and object-based image analysis approaches. SPOT 5 satellite images with four spectral bands from 2003 and 2010 were used to carry out the image classification and ground truth data were collected from Google Earth and field trips. In pixel-based image analysis, a supervised classification was performed using the DT classifier. On the other hand, object-oriented (K-NN) image analysis was evaluated using standard nearest neighbour as classifier. Subsequently SVM object-based classification was performed. Five LULC categories were extracted and the results were compared between them. The overall classification accuracies for 2003 and 2010 showed that the object-oriented (K-NN) (90.5% and 91%) performed better results than the pixel-based DT (68.6% and 68.4%) and object-based SVM (80.6% and 78.15%). In general, the object-oriented (K-NN) performed better than both DTs and SVMs. The obtained LULC classification maps can be used to improve various applications such as change detection, urban design, environmental management and zooning.  相似文献   

Mapping the porosity of international border to pedestrian traffic: a comparative data classification approach to a study of the border region in Austria,Italy, and Slovenia     

Nao Hisakawa  Piotr Jankowski  Gernot Paulus 《制图学和地理信息科学》2013,40(1):18-27

National borders play an important role in everyday life. Interest in border studies has increased with recent changes in geographical locations of the border or the fluctuation of the permeability of the border between some countries, such as in the European Union. Whether the nations are trying to increase traffic flow of the border or to implement stricter border control, having appropriate information of the border is crucial for effective policymaking.

The objective of this research was to identify areas of high porosity, or high permeability, for pedestrians along the southern national border region in Carinthia, Austria using terrain, land use, and road data along with geocomputational methods. Two unsupervised classification methods, the fuzzy K-means clustering and the Self-Organizing Map, were applied to segment the border into homogeneous zones according to topographic and infrastructural attributes. The fuzzy K-means clustering method was chosen for its ability to allow for a continuous approach to classification. With this method, an object can belong, with different degrees of membership, to multiple classes, which is a more realistic reflection of the natural world than discrete clustering, where each object can only belong to one class. However, the fuzzy K-means clustering method does have disadvantages, i.e. the user must determine the number of classes and the input parameters are required to be in continuous format. The second classification method, the Self-Organizing Map, is a type of artificial neural network and was chosen for its ability to automatically determine the number of classes and handle categorical data. The Self-Organizing Map is unique because it can transform high dimensional data into low dimensional display while preserving the topology and spatial distribution of the input parameters. The results of the two classification methods suggest that the fuzzy K-means classification is more effective than the Self-Organizing Map for this situation. However, more research is needed to determine the fit of these algorithms for particular spatial data classification tasks.

The results obtained from this research provide an insight into the permeability of the border region of Carinthia, Slovenia, and Italy to pedestrian traffic and can be potentially useful for decision making processes for tourism development and road transportation management in that region. Furthermore, the approach presented in this article can be applied to other national borders to identify zones permeable to pedestrian traffic.  相似文献   

An enhanced supervised spatial decision support system of image classification: consideration on the ancillary information of paddy rice area     

S. Wan  T. C. Lei  T. Y. Chou 《International journal of geographical information science》2013,27(4):623-642

The analysis, measurement, and computation of remote sensing images often require an enhanced supervised classification technique to develop an efficient spatial decision support system. Rice is a crop of global importance, which has drawn a great interest in using remote sensing techniques for evaluating its production. Ancillary information is widely used to improve the classification accuracy of satellite images. However, few of these studies questioned the importance and strategies of using this ancillary information. The enhanced decision support system in our study has two stages. In the first stage, the images are obtained from the remote sensing technique and the ancillary information is employed to increase the accuracy of classification. In the second stage, it is decided to construct an efficiently supervised classifier, which is used to evaluate the ancillary information. Back-propagation neural network (BPN) with extended delta bar delta (EDBD) algorithm is incorporated into our decision support classifier system. This classifier renders two crucial contributions: (1) the EDBD algorithm accelerates the convergence speed of the learning process and (2) the relative importance (RI) on each band of ancillary information is evaluated rationally.  相似文献   

Predicting potential distributions of geographic events using one-class data: concepts and methods     

Q. Guo  W. Li  Y. Liu  D. Tong 《International journal of geographical information science》2013,27(10):1697-1715

One common problem with geographic data is that, for a specific geographic event, only occurrence information is available; information about the absence of the event is not available. We refer to these specific types of geospatial data as geographic one-class data (GOCD). Predicting the potential spatial distributions that a particular geographic event may occur from GOCD is difficult because traditional binary classification methods that require availability of both positive and negative training samples cannot be used. The objective of this research is to define GOCD and propose novel approaches for modelling potential spatial distributions of geographic events using GOCD. We investigate the effectiveness of one-class support vector machine (OCSVM), maximum entropy (MAXENT) and the newly proposed positive and unlabelled learning (PUL) algorithm for solving GOCD problems using a case study: species distribution modelling from synthetic data. Our experimental results indicate that generally OCSVM, MAXENT and PUL are effective in modelling the GOCD. Each method has advantages and disadvantages, but PUL seems to be the most promising method.  相似文献   

Evaluating walkability: a capability-wise planning and design support system     

Ivan Blečić  Arnaldo Cecchini  Tanja Congiu  Giovanna Fancello  Giuseppe A. Trunfio 《International journal of geographical information science》2013,27(8):1350-1374

We present a methodology and a planning and design support software tool for evaluating walkability and pedestrian accessibility of places which are relevant for people’s capabilities, and thus an important component of quality of life in cities. A multicriteria evaluation model, at the core of the decision support system, is used to assign walkability scores to points in urban space. Walkability scores are obtained through algorithms which process spatial data and run the evaluation model in order to derive potential pedestrian routes along the street network, taking into account the quality of urban space on several attributes relevant for walkability. One of its notable characteristics is a certain reversal of perspective in evaluating walkability: the walkability score of a place does not reflect how that place is per se walkable, but instead how and where to can one walk from there, that is to say, what is the walkability the place is endowed with. This evaluation incorporates three intertwined elements: the number of destinations/opportunities reachable by foot, their walking distances, and the quality of the paths to these destinations. In this article, we furthermore demonstrate possible uses of the support system by reporting and discussing the results of a case-study assessment of a project for the Lisbon’s Segunda Circular (Second Ring Road). The software tool is made freely available for download.  相似文献