Introduction to gis
- 1. INTRODUCTION TO GIS Mr. Franklin Kebungo Ogwankwa GIS Enthusiast franklinogwankwa@gmail.com +254718144060 January, 2021 DISCLAIMER: I don’t have full copyrights of some contents.This is meant to pass knowledge.
- 2. What is GIS? GIS as a Science “Geospatial Information Science is the art and science(study) involving the frameworks and understanding of how geographically referenced data is acquired, processed, manipulated and shared” GIS as a System “Geographical Information System is a computer based system that is designed to capture, manipulate, store, share and visualize spatial data”
- 3. Basic Concepts of GIS as a Science Remote Sensing- capturing data without being in contact with the phenomena
- 4. Con’d GPS(Global Positioning System) – used to assign each location on the earth’s surface coordinates(x,y,..z) for purposes of georeferencing
- 5. Con’d GIS(Geospatial Information System)- computer-based system for processing of spatial data
- 6. Components of GISystem 1. Data- Information about locations on the earth’s surface. 2. People- this is the skilled manpower that helps to read and write geoinformation. 3. Hardware- tangible parts of the computer system through which the GIS software will operate. 4. Software- the functions and tools that are needed to process the spatial data 5. Methods- the procedures required from geographical data capture through to storage, sharing and visualization.
- 7. Con’d
- 8. Spatial Data Types 1. Vector Data -Made up of grids -Represent real world features as Spatial Entities. a) Points – represented in form of x,y coordinates b) Lines – linear in nature, connecting of points c) Polygons – when a set of vertices are joined in a particular order and closed. Represent features at a 2D like buildings, agricultural fields 2. Raster Data -Made up of pixels -Can represent thematic categories, heights, spectral value. a) Discrete Raster-Thematic or categorical raster usually consists of integers to represent values e.g urban LU, Political Boundaries. b) Continuous Raster- Gradual changing data such as elevation, temperature and aerial photograph.
- 9. Topology Topology refers to the study of the mathematics and geometry showing the spatial relationships within geographic features and objects.
- 11. SDI Spatial Data Infrastructure is used to denote the relevant base collection of technologies, policies and institutional arrangements that facilitate the availability of and access to spatial data by readers and writers(people). Data People Institutional Arrangements Technologies Policies
- 12. Application of GIS GIS and Emergency Response 1. Crime Mapping 2. Accident Management 3. Flood risk management GIS and Resource Management 1. Mineral exploration 2. Environmental planning 3. Land use Land Cover
- 13. Cont’d GIS and Decision Making 1. Precision Agriculture 2. Least Cost 3. Project Management 4. Service Provision
- 14. THANKYOU For Any Questions and comments direct them to: +254718144060 Franklin Ogwankwa