This Section Index:

What is a GIS?

Crime Mapping

What is a GIS?

Geographical Information System

“A geographical information system is a group of procedures that provide data input, storage and retrieval, mapping and spatial and attribute data to support the decision-making of the organisation” (Grimshaw, 1994)

The relationship between GIS, computer-aided design, computer cartography, database management and remote sensing information systems. The inter-relationships of the different types of software is a major attribute to the success of GIS, since it can work together with other systems apart from having its own unique characteristics that are not available in the other packages.

Theoretical and practical issues are spreading beyond mere use to incorporate the hard-scientific physical and earth sciences approach to the more complex fuzzy concepts identified by social-scientific theories.

Criminologists debate whether to take the Techno-Centric or the Socio-Technic approach to crime analysis. Whilst the Techno-Centric's dependence on Information Technology is highly attractive, criminologists as also social scientists and in effect require the use of IT but as a tool for understanding social issues.

Spatial analysis and its impact on social research

Crime analysis takes up different forms, from physical pin charting to use of textual documentation to use of tabular data and eventually to the use of crime statistical tools and GIS, aided by value-added modules that cater specifically for crime.

Social-scientific research to date has depended on textual and tabular data that is rarely analysed in a spatio-temporal setting. The use of spatial and temporal analysis of crime data has enabled analysts to combine different resources stored in various formats into a coherent system. With GIS technology, analyses that were not possible in the traditional sense can be identified due to ‘its ability to compare multiple geographic factors and investigate geographic correlations’ and identify the root cause of a problem (Bruce, 2002: 25). It also has the ability to unravel a complex issue that may be too difficult to investigate using conventional or paper-based methods. GIS aids researchers to generate new knowledge through the use of cross-data analysis such as land zoning and offence location through the concept of layering (connected by a common frame of reference system known as x/y coordinates).

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Crime Mapping

Crime Mapping is a successful tool that can be used for a wide range of functions including policy-making, implementation and monitoring interventions on levels of crime and disorder. This can be done through real-time and updated systems that allow crime to be mapped and displayed either on an intranet or on the internet.

Through Web-GIS functionality has enabled users to view crime in the neighbourhood as well as report crime on-line. Most current tools still leave much to be desired but they are being improved to an extent that real full web-maps will soon be regarded as the main modus operandi enabling real-time research. The functions enable regular monitoring and updating data, though work is still required to automatically transform that data to information and eventually to knowledge leading to effective policymaking.

Many authors have debated the issue of use of crime-mapping in terms of effectiveness of the technology to aid crime analysis and in turn crime reduction, such as the need to go beyond the hotspot map and delve into the mechanisms of what makes a crime (Chainey, 2004).

The ability of GIS to form an analysis based on a what, why, who, when, where, why not and how phenomena (W6H) outlined by CMAP has helped crime-mapping tremendously. GIS analysts seek to investigate each of the W6H pivots to identify patterns to reach conclusions whether correlations exist or not. The six pivots can be investigated as follows (CMAP, 2002):

• what categories of crime was committed, what routines can be identified (category analysis), what relationships are there between crimes and other variables;

• why did a crime occur, why did the offender partake in the crime (commonalities of a pattern – root cause of a crime problem);

• who carried out the crime, who witnessed the crime, who was the victim (offender and target profiling);

• when did a crime occur (temporal analysis);

• where did the crime occur, where did the offender hail from (geographic analysis – environmental analysis) – (opportunity and routine activity);

• how did a crime occur (deductive approach - classification and modus operandi analysis);

• why not investigate unrelated variables to elicit if some type of relationship exists (correlation between data layers);

GIS has facilitated the use of any data using both space and time as a way of producing verifiable information on the patterning and links of crime. As indicated in the W6H structure any data that has a link to a geocoded system can be analysed. In this way GIS has brought to the fore situations where previously non-spatial data (attributes) can now be linked to a spatial dataset and that same data would be integrated into a new GIS layer. Such a structure enables the evolution of thematic data to geographical data (locational data based on points on the earth) to a spatial construct (relationship between entities based on the earth) and across a temporal dimension.

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For examples of crime maps go to the Crime Maps Page