Hi, welcome to this hall on the sources of geographic information system data.
Table Of Contents
- Introduction to geographic information system.
- Sources of geographic information system (GIS)
- Revision Questions.
Introduction To Geographic Information System (GIS)
Data input refers to the procedure of automatization of the data and the conversion into forms that can be stored and analyze in computers. This procedure is fundamental in geographic Information system and it differentiates depending on the model (vector or raster) and the origin of the data.
Sources Of Geographic Information System Data
There are many sources of data available for Geographic information system (GIS).
Such sources include the following:
- Land surveying
- Remote sensing
- Map digitizing
- Map scanning
- Field investigation
- Tabular data.
1. Land surveying: Land surveying is defined as the process by which measurement of land is made and then represent such measurements by tables, plans or layout for specific purposes.
It can also mean the measuring and mapping out of the position, size and boundaries of an area of land.
2. Remote sensing: Remote consists of the main sources of digital data for input in a (GIS). Remote sensing provide extremely useful tools for the environmental and natural resources management. They are widely recognized as supporting, and management of the appropriate utilization of resources at the country, regional and global levels. Through the use of remote sensing, employment opportunities are available in a wide range of areas; including agriculture, forestry, coastal development and management, medical technology, mapping and planning, disaster mitigation and environmental management.
3. Map digitizing: Map digitizing involves the extraction of data values from graph, e.g. in most scientific publication only plots but no data values are published. Map digitizing involves a three-step process.
- Import the graph from a file or copy it over the clipboard.
- Define the axes system.
- Digitize it automatically or manually.
4. Map scannings: Another commonly used method for data input is scanning. Existing maps of various scales containing different types of information about the area of interest in small or big detail. These maps can be scanned, Thus, the information of these maps can be fed into a GIS and be integrated with other existing information.
5. Field investigation: During public health emergencies, such bio terrorist attacks and disease epidemics, computerized information system for data management, analysis and communication may be needed within hours of beginning the investigation. Available sources of data and output requirement of the system may be changed frequently during the cause of investigation. Written documents; guidelines and memos important to the epidemics are frequently revised. In this investigation, a database was operational on the second day and the GIS component during the second week of the investigation.
6. Tabular data: This is another types of data commonly used in Geographic information system GIS. It involves the use of special data arranged in tables and such data analyzed and process by computer in order to generate useful information that are relevant to the Geographic information system.
Revision Questions
- Briefly explain the term data input.
- List and explain four sources of Geographic information system data.
- Briefly explain the term GIS.