GIS – 2

What is DATA and INFORMATION in GIS

    Many people think of a GIS as a computer mapping system, its functions are broader and more sophisticated than that. A GIS is a database that is specially designed to work with map data.

     For example, consider the accounting department of the local company. They maintain a large computer database of their customers, in which they store the name, address, phone number. This type of data is called as information or spatial data.

Data

Sample site Vegetation Types

1- Red Mangrove

2- Black mangrove

3-Coconut palm

4- Nut palm

5- Lime

6- Papaya

Information and Data

Collective vegetation types area interpretation vegetation zones

1- Red Mangrove

2- Black mangrove

3-Coconut palm

4- nut palm

5- Lime

6- Papaya

Categories

M – Mangrove

P – Palm

F - Fruit

SPATIAL DATA

        A GIS is a database that is specially designed to work with map data. This type of information is called SPATIAL DATA .  The geographic data in a project can consist of LOCATION, SHAPE and SIZE as spatial data and DESCRIPTIONS and ASSOCIATED DATA as nonspatial attributes.

Spatial data is classified as three main types:

• Point – A point feature is a spot or location that has no physical or actual spatial dimensions, but does have specific location.

• Line – A line is a one dimensional feature having only length, no width. It has a beginning and an end.

• Polygon – A polygon is an enclosed area, a 2D feature with at least three sides and that has area and perimeter, such as parcels of land, agricultural field or political districts.

What is GIS?

GIS stand for Geographic Information System. 

Geographic: The real world; spatial realities.

Information: Data and Information; their meaning and use.

System: Computer technology and its support infrastructure.

DEFINITIONS OF GIS

        A computer based technology and methodology for collection, managing, analyzing, modeling, and presenting geographic data for a wide range of applications.

Advanced computer mapping.

Computerized technology for geographic data.

GIS is a set of computer tools that allows people to work with data that are tied to a particular location.

GIS DESCRIPTION

                Collection 

       

                           Storage and Managing

                                     

                                           Retrieval

                                             

                                                        Conversion

                                                   

                                                                 Analyzing

                                                                                                                                                                                                            Modeling

GIS PROJECT

  

A project usually begins with an assessment of needs. What specific issues must be studied, kind of information is needed to support decision making, what functions must the GIS perform, how long will the project last, who will be using the data.

       Without a realistic idea of what the system must accomplish, it is nearly impossible to design it efficiently. When project developing or modeling raw data is the base data for a project. Once needs are known and any appropriate models have been designed, data collection can begin GIS data are stored as layer. General base layers such as;

• General Reference Map 

• Field and GPS data          

• Remote sensing               

• Soil Survey report           

• Descriptive data

After the data are assembled the analysis can begin, which might requir making changes to the model and/or data. Thus the step of model development can result from above data;

              

• Theme 1:Base Map

• Theme 2:Land Cover

• Theme 3:Population

• Theme 4:Economics

The final result must be checked carefully against reality in order to recognize any shortcomings and provide guidelines for improving future work.

MULTIDISCIPLINARY GIS

It is not just a tool for academic research but functions as a true integrated technology. Phone companies, Banks, Advertising firms, many type of commercial enterprises, emergency services, and many other public and private activities have adopted GIS as a major information and decision-support technology.

APPLICATIONS

GIS work with many different applications, land use planning, environmental management, sociological analysis, business marketing and more.

TECHNOLOGY

Geography , Remote sensing , Demography, Education, Planning , Geology, Engineering , Ecology , Hydrology , Surveying , Archeology, Computer science.