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GEOGRAPHIC INFORMATION SYSTEM

Submitted by:

FELCAR NUÑEZ DANN ANGELO ALBAÑO

Masterands

Submitted to:

MR. DOMINO PUSON Professor

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This report will cover the following information about Geographic Information System:

1. Definition of Geographic Information Systems (GIS)

2. History of GIS

3. Type of data utilized by GIS

4. GIS operations and functions

5. Elements of GIS

6. GIS in Healthcare

7. Nursing and GIS

8. GIS in Health Research

9. Limitations of GIS in Health Research

10. Advantages of GIS in healthcare

11. Current limitations of GIS in healthcare

GEOGRAPHIC INFORMATION SYSTEMS (GIS)

DEFINITION:

GIS is a system of hardware and software used for storage, retrieval, mapping, and analysis of

geographic data. Practitioners also regard the total GIS as including the operating personnel

and the data that go into the system. Spatial features are stored in a coordinate system

(latitude/longitude, state plane, UTM, etc.), which references a particular place on the earth.

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Descriptive attributes in tabular form are associated with spatial features. Spatial data and

associated attributes in the same coordinate system can then be layered together for mapping

and analysis. GIS can be used for scientific investigations, resource management, and

development planning.

GIS differs from CAD and other graphical computer applications in that all spatial data is

geographically referenced to a map projection in an earth coordinate system. For the most

part, spatial data can be "re-projected" from one coordinate system into another, thus data

from various sources can be brought together into a common database and integrated using

GIS software. Boundaries of spatial features should "register" or align properly when re-

projected into the same coordinate system. Another property of a GIS database is that it has

"topology," which defines the spatial relationships between features. The fundamental

components of spatial data in a GIS are points, lines (arcs), and polygons. When topological

relationships exist, you can perform analyses, such as modeling the flow through connecting

lines in a network, combining adjacent polygons that have similar characteristics, and

overlaying geographic features.

HISTORY:

In 1854, John Snow depicted a cholera outbreak in London using points to represent the

locations of some individual cases, possibly the earliest use of the geographic method. His study

of the distribution of cholera led to the source of the disease, a contaminated water pump (the

Broad Street Pump, whose handle he had disconnected, thus terminating the outbreak) within

the heart of the cholera outbreak.

The year 1960 saw the development of the world's first true operational GIS in Ottawa, Ontario,

Canada by the federal Department of Forestry and Rural Development. Developed by Dr. Roger

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Tomlinson, it was called the Canada Geographic Information System (CGIS) and was used to

store, analyze, and manipulate data collected for the Canada Land Inventory (CLI) – an effort to

determine the land capability for rural Canada by mapping information about soils, agriculture,

recreation, wildlife, waterfowl, forestry and land use at a scale of 1:50,000. A rating

classification factor was also added to permit analysis.

CGIS lasted into the 1990s and built a large digital land resource database in Canada. It was

developed as a mainframe-based system in support of federal and provincial resource planning

and management. Its strength was continent-wide analysis of complex datasets. The CGIS was

never available in a commercial form.

In 1964, Howard T. Fisher formed the Laboratory for Computer Graphics and Spatial Analysis at

the Harvard Graduate School of Design (LCGSA 1965–1991), where a number of important

theoretical concepts in spatial data handling were developed, and which by the 1970s had

distributed seminal software code and systems, such as 'SYMAP', 'GRID' and 'ODYSSEY' – that

served as sources for subsequent commercial development—to universities, research centers

and corporations worldwide.

By the early 1980s, M&S Computing (later Intergraph) along with Bentley Systems Incorporated

for the CAD platform, Environmental Systems Research Institute (ESRI), CARIS (Computer Aided

Resource Information System) and ERDAS (Earth Resource Data Analysis System) emerged as

commercial vendors of GIS software, successfully incorporating many of the CGIS features,

combining the first generation approach to separation of spatial and attribute information with

a second generation approach to organizing attribute data into database structures. In parallel,

the development of two public domain systems (MOSS and GRASS GIS) began in the late 1970s

and early 1980s.

By the end of the 20th century, the rapid growth in various systems had been consolidated and

standardized on relatively few platforms and users were beginning to explore the concept of

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viewing GIS data over the Internet, requiring data format and transfer standards. More

recently, a growing number of free, open-source GIS packages run on a range of operating

systems and can be customized to perform specific tasks. Increasingly geospatial data and

mapping applications are being made available via the World Wide Web.

TYPE OF DATA UTILILIZED BY GIS

TABULAR DATA

Tabular data consists of attribute tables that define the parameters of the map features. There

is really no limit to what the tables can contain, whether Boolean strings (True/False), Text, or

Numeric data. For example, a Boolean entry in a cities table may define whether or not each

city is a national capital. A text entry may have the city's name, or the archaeological period in

which it flourished. A numeric entry could have population figures or lat/long coordinates. The

advantage of the relational database system is that the different columns can be sorted and

selected according to the user's need. These selections then appear highlighted on the map.

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SPATIAL DATA

Spatial data places the features on the map. The coordinates of a point are the most obvious

example of this, but it also incorporates projection systems, line and polygon attributes, and

other information. There are two main classes of spatial data: vector and raster.

Vector Data - Most work archaeologists do in GIS is based in vector data. This system of

recording features is based on the interaction between arcs and nodes, represented by points,

lines, and polygons. A point is a single node, a line is two nodes with an arc between them, and

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a polygon is a closed group of three or more arcs. With these three elements, it is possible to

record most all necessary information.

Points represent discrete locations on the ground. Either these are true points, such as

the point marked by a USGS brass cap, such as a section corner, or they may be virtual

points, based on the scale of representation. For example, a city's location on a driving

map of the United States is represented by a point, even though in reality a city has

area. As the map's scale increases, the city will soon appear as a polygon. Beyond a

certain scale of zoom (i.e., when the map's extent is completely within the city), there

will be no representation of the city at all; it will simply be the background of the map.

Here is a view of the Puget Sound area with airports. The airports are stored as points

within the GIS.

Lines represent linear features, such as rivers, roads and transmission cables. Here are

major roads in the Puget Sound region, along with line attributes. In ArcGIS, lines are

also known as "arcs," hence the name "ArcGIS." Each line is composed of a number of

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different coordinates, which make up the shape of the line, as well as the tabular record

for the line vector feature.

Polygons form bounded areas. Polygons are formed by bounding arcs, which keep track

of the location of each polygon, as shown in this image:

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Raster Data - Raster data is characterized by pixel values. Basically, a raster file is a giant table,

where each pixel is assigned a specific value from 0 to 255. The meaning behind these values is

specified by the user- they can represent elevations, temperatures, hydrography, etc. Satellite

imagery uses raster data to record different wavelengths of light. Raster data is advantageous

to vector data in constructing 3D images, as the values for every pixel are calculated through a

process called interpolation. In ArcMap, it is possible to control what type of interpolation

method is used when converting from vector to raster data. Other programs, such as Erdas

Imagine, are tailored specifically to raster data and may be more appropriate for certain

projects

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GIS OPERATIONS AND FUNCTIONS

Data Input

Data input covers the range of operations by which spatial data from maps, remote sensors,

and other sources are transformed into a digital format. Among the different devices commonly

used for this operation are keyboards, digitizers, scanners, CCTS, and interactive terminals or

visual display units (VDU). Given its relatively low cost, efficiency, and ease of operation,

digitizing constitutes the best data input option for development planning purposes.

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Two different types of data must be entered into the GIS: geographic references and

attributes. Geographic reference data are the coordinates (either in terms of latitude and

longitude or columns and rows) which give the location of the information being entered.

Attribute data associate a numerical code to each cell or set of coordinates and for each

variable, either to represent actual values (e.g., 200 mm of precipitation, 1,250 meters

elevation) or to connote categorical data types (land uses, vegetation type, etc.). Data input

routines, whether through manual keyboard entry, digitizing, or scanning, require a

considerable amount of time.

Data Storage

Data storage refers to the way in which spatial data are structured and organized within the GIS

according to their location, interrelationship, and attribute design. Computers permit large

amounts of data to be stored, either on the computer's hard disk or in portable diskettes.

Data Manipulation and Processing

Data manipulation and processing are performed to obtain useful information from data

previously entered into the system. Data manipulation embraces two types of operations: (1)

operations needed to remove errors and update current data sets (editing); and (2) operations

using analytical techniques to answer specific questions formulated by the user. The

manipulation process can range from the simple overlay of two or more maps to a complex

extraction of disparate pieces of information from a wide variety of sources.

Data Output

Data output refers to the display or presentation of data employing commonly used output

formats that include maps, graphs, reports, tables, and charts, either as a hard-copy, as an

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image on the screen, or as a text file that can be carried into other software programs for

further analysis.

ELEMENTS OF A GIS

Hardware and Software Components

Hardware components of a basic GIS work station consist of: (1) a central processing unit (CPU)

where all operations are performed; (2) a digitizer, which consists of a tablet or table where

analog data are converted to digital format; (3) a keyboard by which instructions and

commands as well as data can be entered; (4) a printer or plotter to produce hard copies of the

desired output; (5) a disk drive or tape drive used to store data and programs, for reading in

data and for communicating with other systems; and (6) a visual display unit (VDU) or monitor

where information is interactively displayed. Several GIS software packages are available

representing a very broad range of cost and capability.

Users and Users' Needs

Planners need to carefully evaluate their GIS needs and proposed applications before taking the

decision to acquire an install a GIS. Once a positive conclusion has been reached, its hardware-

software configuration should be designed based on those needs and applications and within

the constraints posed by the financial and human resources available to operate the system.

It is possible that the costs of establishing a GIS exceed the benefits to a single agency. Under

these circumstances, it is worthwhile determining if several agencies might share the GIS. The

potential users must agree on the data to be compiled, the data formats, standards of accuracy,

etc. As a result, the data requirements of a variety of users are made compatible, and the value

of the data increases commensurately.

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Sharing information has its costs as well as benefits. Negotiating with other users can be a

painful task, and compromises inevitably ensure that no one user will get the equipment most

precisely suited to his uses. In this regard, it is important to establish a comfortable working

relationship among sharers.

Information and Information Sources

General reference maps and information on natural hazards and natural resources should form

a "library of knowledge" for any GIS. Virtually all countries have topographic maps, road maps,

generalized soils maps, some form of climate information, and at least the locational

component of natural hazards information (e.g. location of active volcanoes, fault lines,

potential flood areas, areas of common occurrence of landslides, areas of past tsunami

occurrence, etc.). Natural hazards locational data can be made compatible in a GIS with

previously collected information about natural resources, population, and infrastructure, to

provide planners with the wherewithal for a preliminary evaluation of the possible impacts of

natural events.

GEOGRAPHIC INFORMATION SYSTEMS IN HEALTH AND HEALTHCARE

GIS have many potential applications in studying geographically differentiated health and

healthcare phenomena and changes in those phenomena over time, for example,

cardiovascular disease in a given community. Traditionally, two broad types of GIS applications

can be distinguished, which also reflect the two traditions in health geography (geography of

disease and geography of healthcare systems), namely (1) health outcomes and epidemiology

applications and (2) healthcare delivery (services) applications.

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GIS can help health care professionals, public health officials, and community members to

identify potential environmental risks related to the health outcomes and to support decision

making for allocation of scarce disease prevention resources in high-risk areas. Given the

important role that environmental health risks can play in public health, it is critical that

community/public health nurses begin to integrate environmental health assessment skills into

their professional practices by creating assessment and analytic tools to be used at the local

and community-based level. A simple community survey using GIS can be an effective means to

raise awareness about environmental health risk factors and utilizing GIS mapping tools can

further enhance the accessibility of the combined exposure and health information for both lay

and professional audiences.

Moreover, GIS also play an important role in the following: profiling and understanding the

varying needs of target communities; profiling their environment and health and social services

available to them; linking and using such information for planning, optimizing, and targeting

suitable health and social care services (geographically accessible physical services-"fair access

for all") and well-tailored intervention programs to those communities (eg, consumer health

information, self-help and self-care programs); continually monitoring, assessing, and tweaking

such interventions during their execution; testing different "what if" scenarios before making

any financial commitments; and ascribing priorities in a climate of finite resources.

Another use of GIS is in emergency situations, for example, in dealing with bioterrorism,

especially when combined with geographically enabled syndromic surveillance systems such as

RODS (Realtime Outbreak and Disease Surveillance system).

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NURSING AND GEOGRAPHIC INFORMATION SYSTEMS

Some of the uses of GIS in nursing include the following: supporting academic practice, faculty

outreach, and educational initiatives at a school of nursing; visualizing nursing workforce

distribution for policy evaluation; conducting community assessment and nursing research;

conducting health intervention research in diabetes; providing public health nursing education

and practice; and designing population-based health interventions.

Understanding of GIS is essential for nursing science to continue to evolve in the 21st century.

The integration of geography into nursing education, can aid in both for understanding the

geographic factors that influence nursing education outcomes and providing students with

insights about core subjects in the nursing curriculum.

The key advantage that information systems offer is the ability to link data systems in a way

that gives us a much clearer picture about the context in which healthcare is delivered. To take

the example of diabetes, geographical data have identified that prescribing practices and

collection/dispensing of self-testing glucose strips vary widely across areas of different

population density. In the current climate of increased emphasis on self-management in long-

term conditions, GIS can enable us to provide (or at least aim for) self-care support best tailored

to the geographical location of the patient and the type/severity of disease. In this context, GIS

also provide an ideal tool to facilitate integration of service delivery and service evaluation. GIS

allow us to examine questions such as "what would happen if community nurses introduce

telephone or Web-based support for patients with diabetes recently discharged from hospital?"

The various facets of this intervention (availability of telephone services, availability of

broadband Internet, relative costs and reliability of these services, socioeconomic data) could

be mapped by geographical location, and a decision could be made about feasibility of the

service.

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GIS is able to assist nursing as a science as it continues to grow increasingly global in nature,

ever-widening what is envisioned by the person and the environment. Geography, cartography,

and information sciences all lend themselves to the ever-widening boundaries of nursing, both

physical and theoretical in nature, and should not be overlooked. GIS tools and technology are

new ways of incorporating these global realms into nursing science and research, and

ultimately into practice.

GIS IN HEALTH RESEARCH

It is not surprising, then, that health-related fields would find GIS useful. GIS is a tool for

analyzing spatial data, and there are many aspects of health research that analyze the spatial

setting of quantitative phenomena. Generally speaking, there are 2 broad areas where health

fields use GIS. They are, first, the geography of disease and health, and second, the geography

of healthcare.

The geography of disease and health involves describing and analyzing illness spatially. It is

mainly interested in aspects of disease such as spatial clustering, or associations between

disease and elements of the environment. For instance, mapping of certain cancers, traumatic

injuries, and deaths can be used to determine areas of needed patient education for health

promotion, prevention, and care.

The second aspect of health research that typically uses GIS is the geography of healthcare.

Health resources have to be located somewhere, and this area uses GIS to evaluate the spatial

aspect of needs for healthcare and spatial aspects of healthcare provision. Researchers may

look for places where healthcare needs were not being met, and where people travelled long

distances to get care.

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In a unique application of GIS, the National Indian Council on Aging (NICOA) mapped American

Indian elders. NICOA produced documents, one of which was a map of the United States, with

each point on the map representing each American Indian elder. The council reported that this

was the first time GIS was used to map a minority population for healthcare implications. The

study went on to describe and locate available relevant services as well as several disease

processes present, such as diabetes. This was an effort that utilized both types of GIS in health

approaches.

The use of GIS in healthcare is likely to increase in the foreseeable future. Demographic and

financial pressures on healthcare systems are encouraging greater emphasis on measuring

health needs accurately and managing them in ways that are both clinically effective and cost-

effective. Of course, the desired nursing outcome to the use of such a tool is increasing the

understanding of space and time as they relate to access and use. Increasing pressures of

chronic conditions across all age groups necessitate an understanding of not only who your

patient is, but also where and how far, and the environmental impact of that time and space on

health.

LIMITATIONS OF GIS IN HEALTH RESEARCH

As with any tool it is often wise to gain an understanding of its intended uses and possible

problems. There are several notable pitfalls in using GIS in a research project and several will be

mentioned here, following the stages of a typical study. In conceptualizing a study that utilizes

GIS, it is important to recognize that GIS used by non experts can potentially create misleading

results due to the complexities of geographic data quality and scale, as well as more subtle

issues related to misleading maps. This is where creating nontraditional (ie, out of academic

health fields) interdisciplinary partnerships is important until proficiency can be attained.

A second important conceptual concern is the fact that GIS is not well-equipped to handle

temporal data, and is best suited for providing a current snapshot of a phenomenon. This is a

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significant concern in many fields, including those related to health. However, as in the study

underway by the authors, this is overcome by overlaying longitudinal snapshots to see past

patterns and hopefully be able to more accurately predict the future map.

In the second stage of a research project-data collection-researchers should consider issues of

cost and availability. Although free and low-cost data are becoming more available every year,

quite often the data needed for a study are either expensive to obtain, or do not yet exist. For

instance, the authors had to create the database from the census for the map in Figure 5. It did

not come ready-made for importing. However, now the last 2 censuses are readily available in

forms compatible for GIS use.

In the final 2 stages, methodology and analysis, there are several related pitfalls worth

considering. Issues of cause and effect are important in all fields, though GIS was initially

designed for cataloging data, not for analyzing causes. There is a tendency to believe that

because computers are powerful tools, whatever emerges from them is necessarily true. But

just because 2 things coincide in space does not mean that one causes the other, even if they

appear together on a wonderfully expressive map.

Finally, there are social, ethical, and cultural issues to consider. Models such as GIS inherently

simplify, which can be useful in grasping ideas, but can also be problematic when studying the

complexities of humans. An all-powerful GIS that knows all of your whereabouts and activities

would not only threaten privacy, but also would not be an optimum tool for understanding

culture, society, and individual values in isolation of other techniques. This is but another

compelling reason to add nursing's caring voice to this tool as an advocate for person within the

environment whether community or health related.

ADVANTAGES OF GIS TECHNOLOGY IN HEALTHCARE

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Several advantages of GIS technology for public health practice, planning, and research are as

follows:

1) GIS technology improves the ability of practitioners, planners, and researchers to

organize and link datasets (for example, by using geocoded addresses or geographic

boundaries). Geography provides a near-universal link for sorting and integrating

records from multiple information sources into a more coherent whole. This ability to

link datasets can help public health practitioners plan more cost-effective interventions.

For example, suppose that a childhood lead poisoning prevention program could access

residential databases maintained by the tax assessor's office and map the street

addresses of houses built before 1950 (when lead-based paint was commonly used).

Suppose that the prevention program could also access hospital and managed care plan

electronic databases to identify street addresses for new births. Combining these

datasets, the program could apply GIS technology to identify infants at high risk for

exposure to lead-based paint and send a public health worker to follow up with specific

households. By matching the addresses of these infants to a street map (from a

"topologically integrated geographic encoding and referencing" [TIGER] file), using the

"address-match" and "route-scheduling" functions of GIS software, the health worker

can implement and efficient schedule of household visitations.

2) GIS technology provides public health practitioners and researchers with several new

types of data. For example, with GIS technology, local public health departments can

use global positioning systems (GPS) to receive signals from satellites to determine

latitude-longitude coordinates for point locations not found in TIGER files, such as rural

residences, wells, and septic tanks. Public health practitioners can also use digital

imagery from satellites or aerial photos to add details to (or improve the accuracy of) a

mapping project. If a sequence of digital images for a small area of interest is available,

automated change detection can be used to observe changes over time, such as the

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addition of housing developments, roads, and landfills and other changes in land use

and land cover. Public health practitioners can also begin to explore the utility of data

collected by marketing firms about consumer spending patterns, retail expenditures,

and lifestyle segmentation profile.

3) GIS technology encourages the formation of data partnerships and data sharing at the

community level. For example, to develop a map of motor vehicle injuries and fatalities

in a community, a local public health department could develop data partnerships with

the Department of Transportation (for information about traffic flow and accidents),

local ambulance services (for information about injuries requiring transportation by

ambulance to hospital emergency rooms), and the Medical Examiner's office (for

information about fatalities). Some GIS projects may be feasible only if all parts of local

government join together and contribute (for example, developing a regional data

warehouse or obtaining digital aerial photos or satellite images for an entire region).

4) Compared with tables and charts, maps developed using GIS technology can be an

extremely effective tool to help community decision makers visualize and understand a

public health problem. In addition, action is more likely when the decision maker can

see on a map that a problem is occurring in his or her "backyard." GIS technology

enables detailed maps to be generated with relative speed and ease. In turn, this

provides public health practitioners with the ability to provide quick responses to

questions or concerns raised in a community meeting, for example, by preparing

supplemental maps or by displaying more information about a point on the map during

the course of the meeting.

CURRENT LIMITATIONS OF GIS IN HEALTHCARE

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Some of the current limitations of GIS from a public health perspective are as follows:

1) Community health planning and other public health applications remains a relatively

underdeveloped marketplace niche for GIS technology.

2) Current, accurate, low-cost base street maps are essential for epidemiologic uses.

Without an up-to-date base street map, for example, a public health practitioner

investigating a disease outbreak may have to spend considerable extra time and effort

to digitize the locations of cases or may not be able to map all case reports. Current and

accurate base street maps are especially needed for urban areas with high growth and

for those rural areas where residents only have post office box addresses.

3) Practitioners, planners, and researchers, and especially state and local public health

department staff, need training and user support in GIS technology, data, and

epidemiologic methods in order to use GIS technology appropriately and effectively. The

cost of training programs offered by commercial GIS vendors can be a financial burden

for a small local public health agency or individual practitioner. GIS training programs

specifically custom-designed for public health professionals are still relatively limited or

in the early stages of development. The time required for training can be a severe

challenge for organizations in which demands on personnel are already high. Another

drawback is that public health professional specialties currently do not recognize

continuing education credit for individuals who participate in GIS software training.

4) Statistical and epidemiological methods need to be developed to protect individual and

household confidentiality. Even if a single database may appear to have effective

confidentiality safeguards, when several databases are linked within a geographic

information system, the "sum" may be less well protected than the "parts." A false

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identification may be just as damaging to an individual as a correct identification that is

not kept confidential.

5) GIS software continues to evolve rapidly; typically, a new iteration (or upgrade) is

released about every 18 months. Every software package has its strengths and

weaknesses. Current prices for some GIS products (in particular, for Web-enabled GIS

applications and for neighborhood lifestyle segmentation datasets) remain a potential

barrier. In addition, costs for maintenance and upgrades can be substantial.

6) The technology to prepare and display maps on the Web is still in the very early stages

of development. Models and methods for Web-enabled GIS technology need to be

developed for public health applications and field tested. Full GIS capability on the Web

is a considerable technical challenge because GIS software has only recently started to

be developed using Web-accessible programming languages and the size of GIS map

images and data files can be large and significantly slow access and display functions

over the Web. Spatial statistical software programs will also need to be developed for

use with these Web-enabled GIS applications.

REFERENCES:

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http://www.nwgis.com/gisdefn.htm

http://en.wikipedia.org/wiki/Geographic_information_system

http://www.umich.edu/~ipcaa/GIS/General%20GIS%20Concepts.htm

http://www.oas.org/DSD/publications/Unit/oea66e/ch05.htm

envirn.umaryland.edu/.../Geographic%20Information%20Systems%20a%20new%20tool%20for

%20

http://journals.lww.com/cinjournal/Fulltext/2009/01000/Wireless_Technology_Improves_Nurs

ing_Workflow_and.12.aspx

http://courses.washington.edu/gis250/lessons/introduction_gis/spatial_data_model.html