Lecture 9 GIS PDF
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Ain Shams University
Ahmed Ragheb
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Summary
This lecture introduces Geographic Information Systems (GIS), covering topics such as definitions, uses, components and data formats like Raster and Vector. The lecture is from Ain Shams University.
Full Transcript
GIS i-CHEP Selected Topics in Contemporary Issues ASU 114 Dr Ahmed Ragheb [email protected] Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contempo...
GIS i-CHEP Selected Topics in Contemporary Issues ASU 114 Dr Ahmed Ragheb [email protected] Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues GIS Geographic information system GIS can be considered as a completely system (tool) that integrates hardware, software, and data to help decision- makers for rapid answers and problem solving with high efficiency. GIS is an important way for the development and planning of different spatial phenomena in several fields. Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 1 GIS Geographic information system It is a method based on the use of computers for collection, processing, presentation, and analysis of data associated with geographic locations to output information of great importance in taking appropriate decisions. Deals mainly with geographic Geographic phenomena Information Any problem solution needs data Data filtration, management, System modeling and analysis must have a system Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 2 GIS GIS definitions GIS has been described in several ways during its development as a technology: A map connected to a database Computer-based systems that are used to store and manipulate geographic information A computerized database management system for the capture, storage, retrieval, analysis, and display of spatial data Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 3 GIS GIS Uses GIS has become intertwined and related to all aspects of life where it can be used in : Mapping and Visualization: GIS can create detailed maps and visualizations of data for planning, analysis, and decision- making. Location-Based Analysis: GIS can analyze data based on its location, helping find patterns, trends, and predictions. Engineering, Planning, and Management: assist in various fields such as urban planning, transport planning, environment impact analysis, civil planning, and land administration. Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 4 GIS GIS Uses Business, Marketing, and Insurance: GIS can help in business planning, market research, customer segmentation, risk assessment, and claim management. Conservation, Agriculture, and Health: GIS can support environmental conservation, land use and cover changes, wetland mapping, agriculture applications, flood damage estimation, and healthcare Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 5 GIS GIS Components Any GIS system has five main components: PEOPLE: must be qualified and expertized SOFTWARE: must be valid and licensed HARDWARE: must be capable DATA: must be accurate and structured METHOD: must be well defined Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 6 GIS GIS Functions GIS Functions can be summarized as the steps that are taken starting from data capture to display and results analysis. Data Display Capture Visualization Data Store Analysis Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 7 GIS GIS Data ❑ Spatial Data: represents features that have a known location on the earth. This means that it is interested in quantities data that relates to dimensions or locations )i.e. room length, home location). ❑ Non-Spatial Data: represents features that have a descriptive information (i.e. the wall color of a room/the type of used ceramic / the bus number/ bus station name). ❑ Attributes Data: Attribute data are the information linked to the geographic features (spatial data) that describe features. Spatial data and non spatial data linked together through a Database Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 8 GIS GIS Data Format Raster Format Based on a regular covering space into a rectangular grid of rows and columns of cells (also known as pixels). Each pixel having a measured value stored. This value take a range ( from 0 to 255). Most commonly used to represent geographic fields, in which a property varies continuously or discretely over space. Can be stored in various formats, e.g: TIFF, JPEG Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 9 GIS GIS Data Format Vector Format Stores information about discrete objects, using an encoding of the vector logical data model to represent the location or geometry of each object. a single dataset collects information about a set of closely related or similar objects, such as all electric posts in a city. The Vector data model uses coordinate geometry to represent each shape as one of several geometric primitives. Can be stored in various formats, e.g: Shapefile, GML, XML. Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 10 GIS Raster vs Vector Format and Real world Real World Vector Format Raster Format Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 11 GIS Raster vs Vector Format Raster datasets record a value for all points in the area covered which may require more storage space than representing data in a vector format. Raster data is computationally less expensive to render than vector graphics. Vector data can be easier to register, scale, and re-project. Vector data is more compatible with relational database environments. Vector data is simpler to update and maintain. Vector data allows much more analysis capability, especially for "networks" such as roads, power, rail, telecommunications, etc Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 12 GIS GIS role in decision making GIS plays a crucial role in improving planning and decision-making processes by providing a platform to store, analyze, and visualize spatial data. GIS enables users to make more informed choices and optimize various aspects of their operations. GIS web mapping tools enhance decision making by providing accessibility, real-time data, collaboration, user-friendliness, data integration, customization, and interactivity. GIS serves as a decision support system by integrating and displaying data in an understandable form. It aids the decision-making process by analyzing relationships among different kinds of data, enabling users to make more informed decisions and solve complex problems. Prof. Dr. Ahmed Ragheb Lec. 9 ASU 114 Selected Topics in Contemporary Issues 13