Lesson Note On Role of GIS

Role of GIS

Geographic Information System (GIS) is rooted in intellectual practices, populated by data and powered by mathematical analysis. A survey conducted by Schuurman (2004) suggested that currently, the main use of GIS is for spatial analysis, predictive modelling, cartography and visualisation. The SI Industry, also known as the GIS industry, is a rapidly growing industry.  GIS maps the exact location and survey coordinates of an object in space to provide answer to queries using a computer system (Ibid, 2004).  

Furthermore, Monroe County (2008) defines the GIS as a mapping tool for mapping visualisation and geographic analysis.

1.       “Geographic Information Systems are computer based tools for mapping and analysing features and events on earth.  GIS technology integrates common database operations such as query and statistical analysis with the unique visualisation and geographic analysis benefits offered by maps” (Monroe County, 2008).

Thus, the use of GIS is needed to collect data, store, manage, analyse and produce useful information.  In other words, the process of GIS is to input sets of raw data to produce useful output information.  CAS relies on the input of accurate historical records and utilises the functionality of GIS to produce predictions and response plans for this natural phenomena.

Despite the vast potential applications of GIS, the means of integrating the pervasive role and influence of the technology have not kept pace with the current developments and techniques.  Put more simply, the use of GIS has not reached its potential because users are unaware of the possibilities for an integrated GIS in situations where spatial location is involved.  

As a result, this project will use the collection of datasets and integration from different sources to produce useful information for cyclone analysis study.  For this reason, the data acquisition process needs to be of a substantial quality and cover a range of datasets in order to produce meaningful results (Schuurman, 2004).  This is because GIS are dependent on spatial data, with poor quality data producing potentially invalid results (Ibid, 2004).

“The qualities of the data that populate data models constitute the best indicator of the quality of the resulting spatial analysis.  Poor quality or inappropriate data can invalidate the results of the analysis” (Ibid, 2004).

A function of GIS is the ability to query databases using a selection of attributes or selection of locations for special criteria to find the relationships between different results, as shown in Table 2.1.  Hence, GIS draw upon analysis models in the quantitative method.  Therefore, spatial analysis for the project requires the understanding of quantitative data calculations in order to create meaningful implementation.

Initial use of GIS was for cartography and mapping.  However, the methods of computerising cartographic procedures were coincident with the realisation that mapping could be used in analysis through overlays and calculations (Schuurman, 2004).  Nowadays, the analytical technique in GIS is known as spatial analysis,

1.       “Spatial analysis is differentiated from ‘mapping’ because it generates more information or knowledge that can be gleaned from maps or data alone” (Ibid, 2004).

Spatial analysis involves the overlapping of different characteristics of datasets, known as map overlays.  Map overlay, as illustrated in Figure 2.1, made up of collections of similar geographic objects, also known as features, arranged in layers.  It is through the overlay technique, that the result of the analysis can be understood, for example Monroe County (2008).  Every feature in a GIS map is connected to a spatial table in the overlay.  The table is filled with attributes of data that could be examined as information (Ibid, 2008).

Furthermore, GIS divides the world into objects and attribute tables, both of which can be represented spatially by raster or vector datasets which are shown on the map overlay:

1.•Raster dataset that comes from grids, e.g. images, aerial photos.

2.•Vector dataset that comes from mathematical calculations and functions, e.g. points, lines, polygons.

Both types of dataset will be used to produce complete and extensive data in the Area of Study.  

GIS also has programming capabilities, however, in this thesis the programming is limited to simple queries in SQL and VB languages, for example ArcObjects.  As a result, simple map algebra and

Figure 2.1 - Data and Information comes from a set of layers (ESRI, 2008; Geoscience Australia, 2008).

calculation functions can be achieved.  Therefore, the main tool for CAS involves visualisation and analysis using GIS.  

For this reason, the CAS is associated with SI because of the diverse type of applications possible.  In addition, CRC SI (2008) defines the use of SI for the Australian community is necessary to the community, especially when maps of all kinds are produced, displayed and analysed using technology that the wider spatial information industry provides.

This is also evident when Schuurman (2004) points out that the challenges are associated not only for visualisation and analysis, rather with modelling spatial phenomena using GIS. 

1.        “Spatial analysis and modelling are increasingly used to predict outcomes, and plan for future development or natural hazard.  The capacity of GIS have been extended from managing data and map distribution to model interactions among different attributes of the spatial objects and use the information to predict future events” (Ibid, 2004).

As a result, SI holds such importance because of various forms of GIS functionality, for example enquires, integrates, manages, analyses, maps, distributes, and uses geographic, temporal and spatial information and knowledge.  Hence, it is important for the system to provide adequate planning, decision-making and operational needs of people and organisations of all types (CRC SI, 2008).

In particular, ArcGIS Desktop software from ESRI has been chosen for the course of this thesis because, 

1.       “ArcGIS is full featured geographic information system (GIS) software for visualising, managing, creating and analysing geographic data.  Using ArcView, you can understand the geographic context of your data, allowing you to see relationships and identify patterns in new ways” (ESRI, 2008)

In other words, ArcGIS is a GIS enterprise developed and maintained by ESRI.  For the course of this project, the desktop GIS platform is used to produce spatial analysis, visualisation and cartography, and spatial data management.  Additionally, the software could be used for authoring, serving, and using geographic information.  

Furthermore, ESRI (2008) details features of the ArcGIS 9.2 Suite, which is the version released since the start of the thesis, that are applicable to the CAS such as:

1.•Quality mapping for the study area base maps

2.•Spatial Analysis for socio economic and population data

3.•Data Use and Integration of Australian Bureau of Statistics datasets

4.•Data Query and Exploration of PSMA LGA datasets

5.•GIS Deployment of the evacuation system

6.•Map Viewing and Navigation for the evacuation maps

7.•Map printing for all key maps 

8.•Configurable and Customisable for future studies

Additionally, it is the most widely used software in industry, with superior features to its closest counterpart, as shown in Figure 2.2.  Perhaps due to its functionality and spatial analysis it would justify the use of ESRI software platform.

Figure 2.2 – GIS users

(Directions Magazine, 2003)

For this reason, ArcGIS 9.2 is the main component for this project, used as the platform in the framework because of its capability to create, manage, publish and disseminate the GIS knowledge for all the society (ESRI, 2008).  GIS is the main core of this project that will be used as a tool to integrate Cyclones and its spatial analysis for the visual representation of the study area.  

Since the study will be focussed on GIS, Table 2.2 shows the types of activities that will be undertaken using GIS.