The overlay functions in Geographic Information Systems (GIS) are considered as one of the basic functions of these systems, and often, a variety of data stored in layers may be integrated together to generate new layers that contain useful informati
on for decision-makers. All geographic objects are stored in layers and usually rely on crisp set theory, whether, stored in a vector or raster format. In many cases, boundaries of classes or objects are not clearly defined, or when we perform classification of features into classes, the geographic objects located in the boundaries of classes could be classified into the wrong class. This research aims to develop overlay functions methodology based on fuzzy logic, reclassify the objects into fuzzy classes, and study the usability of this method to integrate data of specific phenomenon to help make optimal decisions. To implement and examine this idea, a set of Fuzzy Membership Functions was developed using the Python programming language embedded within the ArcGIS environment. Through this Fuzzy Membership Functions, the user can generate fuzzy sets and combine with each other according to one of fuzzy operations, and thus the generation of fuzzy sets allows supporting the right and reliable decision. To test the proposed fuzzy model capabilities, it has been applied in Tartous governorate to select suitable tourist facility sites in accordance with groups of factors. In summary, data integration using proposed fuzzy overlay functions can improve the reliability of data representation and thus the reliability of make the best decisions.
Geographic Information Systems (GIS) present one of the most important 3D modeling techniques of cities, which has become a very important and necessary for representing of contemporary cities, and doing different analyses, with the aim of finding so
lutions to the problems raised through a virtual model of reality. In addition, 3D GIS play an important role in urban planning. Despite the presence of a large number of programs capable of dealing with 3D objects, many of these applications require high technologies and advanced tools for the representation and analysis of 3D objects. The objects of 3D models represented in GIS can be associated with a set of queryable attributes, and this is not available in other 3D modeling software. This Research aims to highlight the importance of procedural 3D modeling of cities in GIS environment using ESRI CityEngine. A set of CGA (computer generated architecture) rules - programmed by procedural modeling language in CityEngine- will be presented to generate realistic 3D models that can represent all elements of cities and its infrastructure. Then, all the objects will be exported to a Web Scene viewer, which allows the creation a comprehensive platform to present a system to support decision-making, and facilitate project management related to the management of cities. The research methods will be applied to Tartous governorate through designing and modeling of proposed residential area. This study will include CGA rules applied to create a 3D model of proposed area, it will show the importance of GIS in modeling and representation of cities.
Free and Open Source software (FOSS) is one of computer software, which source code can be accessed, freely used, modify, and distribute by anyone. It is produced by many of people or organizations, and distributed under licenses that comply with the
open source definition. This software has recently begun to play an important role in the academic and scientific research field, as in the professional field. In the past few decades, Geographic Information Systems (GIS) has seen very high growth rate, and this development included each of commercial and open source GIS software.
This research aims to show the great potential of Free and Open Source Geographic Information Systems (FOSS_GIS), and motivating to adopt it in developing countries, as a means to reduce licensing costs, promote local technological development through access to the source code and developing these systems. A case study is taken, in which we have tried to highlight the most important advantages of this software (i.e. FOSS_GIS), such as ease of implementation and good use, the ability to analyze and display of spatial data, professional maps production, and functionality emulator to commercial GIS software. The case study included the methodology of spatial suitability analysis, which is one of the main tasks of GIS; this methodology has been applied to choose the optimal site of urban project in Sheikh Badr area (Tartous Governorate) by proposing a set of general conditions. Using optimal site selection analysis of urban project helps to avoid the indiscriminate expansion and the irregular land-use. The free and open source software QGIS was used in this research, as well as the algorithms and tools of GRASS and SAGA softwares.
Key Words: FOSS_GIS, spatial analysis, QGIS, optimal site selection, Sheikh Bader area
Three dimensional modeling of utility networks is an important mean of networks design, implementation, management and maintenance. During the modeling process, we face a wide range of processes and procedures to arrive at the correct final model.
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his research proposes a semi-automatic methodology for 3D modeling of infrastructure networks in GIS environment. This methodology is based on the ModelBuilder in ArcGIS software by developing two tools to automate the construction processes of 3D networks.
The first presents a tool to create a 3D Manhole layer from points, and the second is a tool to create a 3D pipe layer. For both tools, a work algorithm has been built, in addition to designing user interfaces elements. These tools are stored in a Toolbox called “3D Manhole & Pipe.tbx”.
The proposed methodology is an easy and an effective way to build 3D network models, and the developed tools allow the implementation of a set of necessary processes needed to build 3D networks.
