- What Is a GIS?
A geographic information
system (GIS) is a computer-based tool for mapping and analyzing things that
exist and events that happen on earth. GIS technology integrates common database operations such as
query and statistical analysis with the unique visualization and geographic analysis benefits offered by
maps. These abilities distinguish GIS from other information systems and make it valuable to a wide
range of public and private enterprises for explaining events, predicting outcomes, and planning
- How GIS Works
A GIS stores information
about the world as a collection of thematic layers that can be linked together
- Role of GIS
Disasters are usually
spatial events (floods, earthquakes, hurricanes, wildfires, hazardous spills,
unrest, famine, epidemics, and so forth). Mapping and information acquisition is vital for disaster
management. GIS supports all aspects of disaster management.
GIS is essential to
effective preparedness, communication, and training tool for disaster
Disaster management requires response, incident mapping, establishing priorities, developing action
plans, and implementing the plan to protect lives, property, and the environment. GIS allows disaster
managers to quickly access and visually display critical information by location. This information facilitates
the development of action plans that are printed or transmitted to disaster response personnel for the
coordination and implementation of emergency efforts.
- GIS in Law Enforcement and Criminal Justice
The distribution of crime
across the landscape is not geographically random since crimes are human
phenomena . For crimes to occur, offenders and their targets - the victims and/or property - must exist at
the same location for a period of time. Several factors, including the lure of potential targets and simple
geographic convenience for an offender, influence where people choose to break the law. Therefore,
geography plays an important role in law enforcement and criminal justice.
Investigators might use
complex maps to observe trends in criminal activity, and maps may prove
invaluable in solving criminal cases. For example, they may use maps to better understand the hunting
patterns of serial criminals and to hypothesize where these offenders might live. Some of the most helpful
maps for those persons who investigate crimes simply indicate where incidents have occurred. Prior to
recent technological advances, they typically placed pushpins in wall maps to examine the spatial
distribution of crime locations. However, modern GIS software allows them to produce more versatile
electronic maps by combining their databases of reported crime locations with digitized maps.
GIS in law enforcement and
criminal justice means crime analysis via crime mapping electrically. It
provides a valuable spatial element to link analysis and crime analysis tools. Prosecutors use GIS to map
filing locations and workloads and determine geographic areas of responsibility. It also enables them to
provide interactive mapping presentations, including photographs, video, fingerprints, and documents, to
dramatically improve case preparation and presentation. For investigators, GIS displays criminal intelligence
and crime analysis information graphically with both mapping and link analysis capability.
Because incident data can be
organized by geography (location of the crime) in addition to offender name,
time of day, and type of crime, it can be displayed in a GIS. GIS will allow users to find the data for a
certain time frame and area and display it on a map. The map can include nearby landmarks like streets and
schools, and different colors and symbols can be used for different crime categories, painting a real picture
of the data and making it easier to interpret. After depicting incident data on a map, users can conduct further
geographic analysis and generate reports summarizing events.
GIS can also be used to
calculate crime density values, such as the number of crimes per square mile.
density values can be used to create a choropleth map. Density maps offer a broader look at where crimes
occur without investigators having to interpret a large number of individual locations.
Presenting crime information
graphically provides a powerful decision making tool for investigators since it
provides a new perspective, and trends and patterns become more apparent. The visual format shows
relationships and patterns that are buried in the data. GIS is a vital tool that will help investigators better
understand the region they are responsible for and the crime they are having so that informed decisions can be
- Useful documents for GIS crime mapping
Mapping Crime: Principle and Practice
This NIJ Research Report
introduces the science of crime mapping, visualizing crime data through the
medium of maps. The report presents how GIS are used to analyze crime problems. Must for detailed study
for GIS crime mapping.
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Mapping Out Crime: Providing 21st Century Tools for Safe Communities
The U.S. Department of
Justice in conjunction with the National Partnership for Reinventing Government
has released the report of the Task Force on Crime Mapping and Data-Driven Management.
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Computerized Crime Mapping
Articles include a
discussion of crime mapping by NIJ Director Jeremy Travis, and a report on
Gore's announcement of a $93 million dollar grant to help law enforcement with their technology needs.
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- GIS developed by U.S. Department of Justice, available to public
The GIS Staff was formed in
1994 in order to provide mapping services to Criminal Division attorneys
and to provide spatial analysis of resource allocation for administrative planning. Criminal Division
attorneys use the maps to show the court where the alleged crime(s) took place. The maps also help explain
some of the circumstances that may have contributed to the crime(s). The maps are made using geographic
data and/or high-resolution aerial photographs and may include an assortment of annotation and crime
scene photographs. The GIS Staff has also developed several law enforcement GIS applications for
attorneys and for police departments.
The GIS Staff developed the
Spatial Crime Analysis System (SCAS). The SCAS is designed to serve as a
both a strategic and tactical tool for crime analysts, police officers, and managers in police departments. The
SCAS allows police departments to analyze crime spatially and temporally, identify crime trends, and
identify crime hot spots. The SCAS allows the user to produce maps, tabular reports, and histograms. The
GIS Staff is currently developing a new crime analysis system called RCAGIS (Regional Crime Analysis GIS).
The Spatial Crime Analysis System (SCAS)
The Spatial Crime Analysis
System (SCAS) is an ArcView-based GIS application designed to allow police
departments to perform sophisticated spatial analysis and mapping of their incident-based crime data.
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The Regional Crime Analysis GIS (RCAGIS)
The RCAGIS Crime Analysis
System was designed specifically to assist in the analysis of crime incident
data across jurisdictional boundaries.
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- Examples of GIS in disaster management
Police Go Online to Fight Crime
The Philadelphia Police
Department (PPD) developed a stolen vehicle tracking application that enables
officers to see the location of recovered vehicles in relation to the area in which they were stolen.
The crime analysis unit has
begun to use ArcView Spatial Analyst to observe crime densities. This
application proved particularly useful in breaking a large drug enforcement case. Street maps showing
building footprints and crime densities have enabled the PPD to do more effective planning in the operation.
The generic incident mapping
application they designed will enable officers to define a series of parameters
on a form, submit the request, and have a map of incidents returned. Identification requests will return
multiple incidents and show related arrest information.
Officers will be able to
access several reports including summaries of activity for a user-specified
lists of incidents occurring at a single address, and charts analyzing day-of-week and time-of-day
relationships for aggravated assaults and robberies. Another benefit of the Intranet-based applications will
be the team's ability to turn around late-breaking information immediately.
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GIS Supports Crime Analysis in Karachi, Pakistan
The Citizen's Police Liaison
Committee (CPLC) has recognized that crime in Karachi has a spatial
component. By applying GIS, crime can be geolocated (usually by street address) to reveal significant
trends, patterns, and relationships. This supports crime analysis, enforcement planning, and more effective
But in an extensive,
unplanned city like Karachi, the street addressing system is confusing or
This presents a major problem for law enforcement agencies that respond to incidents. Often, the only
means of navigation is by local knowledge or landmarks known to the authorities and general populace.
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GIS Helps Visualize Natural Hazard Risks
The Metro Area Disaster
Geographic Information System (MAD GIS) is designed to assist certain local
governments in Oregon to prepare for, and respond to disasters
MAD GIS can be used in many
ways. It can help identify zones for new construction that need
site-specific hazard investigations. It can create maps and inform the development of risk-based standard
operating procedures for assessing damage along regional emergency transportation routes. MAD GIS also
can help prioritize preventative and early recovery strategies for vital systems such as electricity, gas, and
water that cross jurisdictional boundaries.
Using MapObjects software's
rich set of developer objects, MAD GIS can be used to show where schools
are located in relation to earthquake hazards or where hazardous materials sites are located in relation to
landslide hazards and floodplains.
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Protects Its Air, Land, and Water with GIS
Department of Environmental Protection (DEP) is responsible for protecting
Pennsylvania's air, land, and water from pollution and for providing for the health and safety of more
than 12 million citizens.
The Pennsylvania DEP
Facility Analysis System (PFAS) maintains the functionality of the DEP's
database infrastructure and custom applications while creating entirely new methods of viewing and
analyzing the data.
The system was
developed to provide customized spatial and tabular query, location, and
over a standard Intranet connection via a browser. It allows all staff members (such as secretaries
and permit reviewers) personal computer access to view and generate reports for permitting subfacilities
within the State. And it provides the same information to the public via the Internet.
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for Emergency Response
Consequences Assessment Tool
Set (CATS) software provides powerful disaster analysis in real time with a
rich set of information integrated from a number of sources.
In case of bioterrorist
attacks, CATS helps people to accurately assess the immediate risks to the
as well as to predict the likely spread of the biologic agent, track where the attack took place, who is affected,
how the attack might be spreading, and how to reduce exposure to populations as fast as possible. CATS
manages a wealth of information in an unprecedented manner by coupling real-time wind speed and direction
data off the Web with ArcView GIS and the ArcView Spatial Analyst extension supplying powerful data
integration, analysis, and visualization tools.
Utilizing ArcView GIS and
ArcView Spatial Analyst, CATS comes with a wide range of georeferenced land,
demographic, and infrastructure information accessed via the Internet from a number of diverse database
sources. Information on schools, hospitals, telecommunications assets, roads and highways, utility
infrastructure, population information, and more is accessible with CATS.
For the Fire Department,
CATS allows users to model events such as explosions, toxic releases, or other
emergency situations. Users can analyze how those events affect surrounding people and how to best respond
to these events.
Law enforcement officials
can use the software for crowd control, area closure, investigative response,
other law enforcement tasks. The mapping element gives users the ability to use data visualization as a decision
making tool and to easily share this data among cooperating agencies.
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Aid for Kosovo Guided by GIS
In response to reports of
deaths from malnutrition and starvation among the Kosovo refugees, a
humanitarian airdrops was initiated by the New York-based International Rescue Committee. This program
was funded by the United States Agency for International Development's Office of U.S. Foreign Disaster
The function of GIS in this
operation was the production of highly customized mapping of each flight plan
and target zone for the air crews. The crews were given a new map each day showing details such as the cargo
weight, the drop coordinates, the call sign, and radio frequencies for the day, as well as the precise route and
locations of emergency landing sites. GIS was also used to map and monitor the amount of aid that had been
dropped. The map showed which areas had been targeted and which had not received aid in the last few days.
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the Salton Sea
The Salton Sea is
dying because of its high salinity. The Salton Sea Authority intiated the
project of reducing
salinity in the Salton Sea to ocean level by constructing dikes and concentration ponds to trap salts and pump
saline water out to nearby dry lake beds.
GIS is used to create
and run models in order to generate a map showing the most suitable areas to
a pipeline. The intermediate maps are weighted by how much they contribute to the cost of construction, and
then the maps are combined. The final result is a suitability map, which shows the most suitable areas for
construction of the desalinization pipelines, given the input data and constraints. Then the suitability map is
converted into a least-cost path map, which shows the paths with the lowest construction costs.
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