GIS Lecture Notes PDF

DEFINING GEOGRAPHIC INFORMATION SYSTEM  "is a computer system capable of capturing, storing, analyzing, and displaying geographically referenced information; that is, data identified according to location. Practitioners also define a GIS as including the procedures, operating personnel,...

DEFINING GEOGRAPHIC INFORMATION SYSTEM  "is a computer system capable of capturing, storing, analyzing, and displaying geographically referenced information; that is, data identified according to location. Practitioners also define a GIS as including the procedures, operating personnel, and spatial data that go into the system.“ USGS (United States Geological Survey)  "is a computer-based tool for mapping and analyzing things that exist and events that happen on earth. GIS technology integrates common database operations such as query and statistical analysis with the unique visualization and geographic analysis benefits offered by maps." ESRI  The spatial (geographic) part differentiates a GIS from a standard computer database. GIS OVERVIEW  GIS is a computer-based tool for solving geospatial problems.  It integrates information in a way that helps us understand and find solutions to geospatial problems.  GIS Definition: A system for capturing, storing, analysing, and displaying geographic data.  Components: People, data, hardware, software, and methods.  Core Functions: Capturing, storing, querying, analysing, and displaying spatial data. GIS COMPONENTS  Hardware (computer, screen, keyboard, printer, scanner, digitizing table, etc.)  Software (specific computer application programmes, e.g. ArcView, IDRISI, QGIS, that can retrieve data and shown as maps or tables, edit and change data, capturing and storing of data, querying and analysis of data)  Data (spatial data – such as town, rivers, roads, and attribute data – that describes the characteristics of a geographic feature such as numbers, length, area, type of building, clay content, etc.)  People (trained specialists, data developers, system managers as well as the daily users)  Methods (methods and techniques such as properly developed implementation plans, business rules and models true to each unique organization) The main goal of GIS is to provide spatial information to decision makers DATA VS INFORMATION  Data: Raw facts or figures - pieces of information, but not information itself.  Data is collected and stored in databases. When data are processed, interpreted, organized, structured or presented so as to make them meaningful or useful, they are called information. Information provides context for data.  In a GIS, spatial analysis and modelling are the main source of information.  Spatial analysis - a set of methods and tools for performing operations on spatial data in order to obtain additional information.  DATA OR INFORMATION? Example 2: Example 1: City Temperature (°C) Cities near the coast, like Cape Town and Durban, tend to have more Cape Town 22 moderate temperatures compared Johannesburg 25 to inland cities like Johannesburg Durban 27 and Pretoria. This suggests that Pretoria 24 proximity to the ocean affects climate, with coastal cities generally experiencing less temperature variation. FUNCTIONS OF GIS  Collecting and capturing of data  Storing and management of data  Recall and processing of data  Transforming and integration with other data  Analyses of data  Display data as maps and information tables  GIS FUNCTIONS CAPTURING DATA provide methods for entering geographic and tabular data STORING DATA provide a means of storing geographic data QUERYING DATA provide tools for finding specific features based on their location or attributes ANALYSING DATA able to analyse the spatial relationship among multiple datasets/layers to answer questions and solve problems DISPLAYING DATA have tools for displaying geographic features using a variety of symbology. The end result is best visualised as a map graph or report OUTPUTTING DATA take displays created through a GIS and outputting them into a distributable format for example pdf, jpg or tiff formats FUNCTIONS OF GIS - EXAMPLE “How could we use GIS to reduce traffic congestion in a city?”  Step 1: Data Collection  Gather traffic data, road layouts, and population density maps.  Step 2: Data Analysis  Analyse congestion areas, times of day when traffic is worse, and which routes are overused.  Step 3: Visualisation  Create heatmaps showing the intensity of congestion at various times of day.  Step 4: Solution  Propose new routes or public transport lines based on the data. GIS: TOOLS/SOFTWARE Free and Open Source Software:  Quantum GIS (QGIS)  Geographic Resources Analysis Support System (GRASS )  Flowmap Paid and Commercial/Enterprise Software:  ArcGIS  ENVI  ERDAS Imagine Programming Languages and Cloud Computing:  Google Earth Engine  Python, R  Amazon Web Services, Microsoft Azure , Alibaba Cloud Computing  WHY DEVELOP A GIS?  Improved Decision-Making: GIS helps visualize complex data to identify patterns, trends, and relationships, leading to more informed decisions across various fields.  Resource Optimisation: GIS allows for efficient allocation of resources by analyzing geographic data (e.g., disaster response, land use, or infrastructure development).  Environmental Monitoring: Track changes in land, water, and ecosystems over time, allowing for better conservation and resource management efforts.  Problem Solving: GIS supports data-driven problem solving by integrating different layers of information, helping tackle challenges like urban planning, transportation, and public health.  Increased Efficiency: Automating data collection and analysis processes with GIS improves operational efficiency in sectors like logistics, agriculture, and public services. CASE STUDY: USING GIS FOR DISASTER MANAGEMENT IN KWAZULU-NATAL  Context: KZN is prone to natural disasters like flooding, which causes severe damage to infrastructure, homes, and leads to loss of life.  Use of GIS:  Flood Risk Mapping: GIS can predict high-risk areas by analyzing topography, rainfall patterns, and water flow, helping authorities prepare in advance.  Resource Allocation: GIS will enable more efficient distribution of emergency services and aid to the most vulnerable areas in real time.  Evacuation Planning: GIS can be used to design optimal evacuation routes, ensuring safe and timely evacuations during disasters.  Monitoring Recovery: After a disaster, GIS will help track the extent of damage and monitor recovery efforts to ensure that infrastructure is restored effectively. ADVANTAGES OF GIS  Ability to view, visualize and interpret data in the form of maps, charts and reports - relationships and trends easy to see and understand  Improved decision making and problems solving through specific and detailed information regarding locations of features and phenomena  Reduce costs and increase efficiency  Improved communication between organisations or departments