Managing Enterprise GI Using Intranets
In 1994 the Open GIS Consortium (OGC) was launched
with the mission of improving the interoperability of GIS. At
the heart of this mission was a need to find a common standard
for the structuring of topological features, among which the structuring
in a SQL environment. This common standard has evolved in to OGC
"Simple Features Specification for SQL". However, from
a practical point of view this specification is only of value
once it is embodied within systems that are used in practice.
In 1997 two major commercial packages came on the market. ORACLE
Corporation Spatial Data Option (SDO) and Environmental Systems
Research Institute Spatial Data Engine (SDE). Both with the intention
of using the OGC standards as the basic building block for structuring
vector databases.
The main aim of this thesis was to evaluate
how well SDO and SDE apply the OGC specification and furthermore
establish whether or not the practical application of these tools
and standards meets the needs of users for the topological structuring
of geographic data. To do this a case study data set from the
Dienst Landelijk Gebied in the Netherlands was implemented in
both SDO and SDE. The next set of four major aspects were found.
Simple and non simple geometries can be incorporated
in SDO and SDE. However, not all OGC simple geometries are supported
and more importantly many non simple topological structures are
not accommodated at all. OGC is recommended to address rules on
conversion of non simple to simple geometries.
SDO and SDE differ greatly in their set of geometry
validation rules and the way they interpret the OGC specification.
This means that both systems will react differently when data
are inserted. Inserting the same set of data in both packages
might result in different implementations in both packages.is
a most unwanted situation. Standards on converting non-simple
geometries is of great importance.
The storage architecture and physical data structure
of SDO, in numeric format, and SDE, in binary format, is in accordance
with the OGC specification. Storage format in itself is not that
much a users concern. However, in order to compose efficient retrieval
statements the user must have knowledge about the implemented
data structure of geometry’s and the spatial indexing mechanism.
Retrieval of data in SDO and SDE is highly bound
to the concepts of the developers. In SDO this is a full SQL integrated
environment. In SDE it is a defined Application Program interface.
Retrieval is an aspect OGC is recommended to address.
From a user's point the positive message is
that with proper care, spatial data, can be incorporated, managed
and set available in both packages, following the rules of OpenGIS.
Still there is much work to be done before the OGC specification
and its implementation in products like SDO and SDE will provide
GIS products which are truly interoperable in character.
Electricity is supplied from the National Grid,
to industry and to our homes, via a network of substations, overhead
lines and underground cables. The reliability and performance
of this network has to meet certain standards set down by government,
as well as efficiently delivering electrical units on behalf of
the supply companies. Therefore, electrical distribution companies
who operate these networks need to run various support systems
– both computer and paper based, to help them manage their
networks.
This study examines how Geographical Information
Systems (GIS) can be used to manage the process of asset maintenance
– in particular for the sections of overhead network which
are exposed to the elements and are more prone to faults and damage.
Many UK electrical distribution companies are
using GIS for various purposes including asset maintenance and
this study will review some of these systems.
NORWEB Distribution – an electricity distribution
company in the North West of England currently use a GIS system
– OHMS (Over Head Management System) which is essentially
a map management system. This study will explore how this system
could be extended by using ‘GIS-type’ functionality,
to produce a tool for managing the overhead asset maintenance
process.
It will demonstrate how the digital asset data
already captured can be linked to other data sets, and by using
spatial queries, to present this information in a useful form
to the Network Operations section. It will also review data quality
issues and make recommendations on how this might by improved.
Decision-making for large transport infrastructure
projects is largely a spatial problem. Geographic Information
Systems have already been used for functions such as technical
planning and for preparing environmental impact predictions. There
were some limitations to this approach: the cost in time and money
(design of the system, data gathering), the need for powerful
computers and scarce specialist expertise. The general public
was sceptical of technical presentations which were not easy for
the layman to understand.
Decision-making and conflict as experienced
in the planning of the Betuwe freight railway in the Netherlands
were examined. A research GIS was assembled using off-the-shelf
hardware and software, and data supplied by the province of Gelderland
(representing one half of the total route of the railway). It
was demonstrated that many of the crucial spatial issues within
decision-making and conflict resolution could be handled within
this system, as could issues within the field of Environmental
Impact Assessment.
However, the history of the case showed that
although GIS was used as a tool by the developer to prepare technical
presentations, and to prepare the EIA report, communication with
the public was poorly managed; public meetings aroused much opposition
to the project.
Drawing together conclusions from the research
GIS, from the history of the planning of the railway and from
present development in Geographic Information Technology in general,
it is proposed that GIT can now be used more effectively in such
cases.
First, the constant improvement of off-the-shelf
hardware and software, the growing availability of digital spatial
data and of the expertise built up in the application of spatial
systems mean that the cost in time and money of assembling such
a system is reduced. Second, open and organised use of GIT can
allow better communication and transparency in decision-making,
better collaboration amongst decision-makers and improved public
participation. The EIA procedure within the Netherlands provides
a possible organisational framework within which GIT could operate.
The EIA requirement for monitoring environmental effects during
construction and operation can also be handled using a GIS. Third,
GIS combined with virtual reality techniques allow much better
public presentation and participation. Also developments towards
Open GIS make it possible to link individual systems having specific
functions (technical planning, decision-making, EIA, public communication)
into a distributed system, so that changes in one area are immediately
updated throughout the system, and all stakeholders can have access
to current information.
Spatial intraspecific variation patterns arise
through the evolutionary processes of natural selection and genetic
drift acting within the constraints of the environment and population
history. Complex patterns of variation are observed in the cricket
Ephippiger ephippiger (Saddle-backed Bushcricket) in South-west
France. These complex patterns have resulted in considerable debate
over their origin and the taxonomic status of the organism. Here,
E. ephippiger trait and environmental data sets are integrated
and compared using the Idrisi and MapInfo Geographical Information
Systems (GIS). Inverse distance surfaces are generated for each
trait and analysed through a variety of uni-, bi- and multivariate
statistical and mapping techniques. Four simple component pattern
types are revealed which can be combined in different ways to
produce the observed trait patterns. An evolutionary history hypothesis
is constructed from the relationships between the intraspecific
variation patters, environment, landscape and the post-glacial
history of Western Europe.
The use of Geographical Information Systems
(GIS) within property valuation and mass appraisal has yet to
be fully realised within the United Kingdom. GIS technology provides
the ability to measure proximity and location and thus provides
a natural support tool for Computer Assisted Mass Appraisal (CAMA).
Using empirical data on a study area of Carrickfergus,
Northern Ireland, this project investigates how GIS can provide
a credible support tool for mass appraisals. More importantly
it investigates how the spatial element of GIS can allow location
to be modelling as an indice and applied as a factor using residual
error. Investigation incorporates a selection of common surface
interpolation techniques and assesses the potential of ‘Value
Influence Centres, how these are located, measured and applied
to improve predictive quality. This work compares the surface
based predictions with the more familiar mass appraisal techniques
of multiple regression models. In conclusion, a series of procedural
refinements are discussed an recommended for future research.
Subsurface fluid migration is a multi parameter
process depending on a lot of different components like, e.g.,
tectonics, facies, lithology, hydrochemistry and hydraulics and
is a key component of petroleum and geothermal exploration and
production in sedimentary basins. The area of investigation is
the Molasse Basin in Upper Austria which is a typical asymmetric,
compressional foreland basin at the northern margin of the Alps.
Due to petroleum exploration and production there exists an excellent
data set of more than 500 wells ranging in depth from 1000m to
4000m. Three different fault systems have been active at different
times from pre-Tertiary till present and have a large impact on
hydrocarbon migration and fluid flow. There exist two components
of fluid migration:
- N-directed migration of hydrocarbons and
- E-directed fluid flow of deep groundwater
at basin scale in a Jurassic carbonate aquifer which is the
main target for geothermal exploration in this area.
A Geographical Information System (GIS) has
been use d(1) to integrate different data sets available using
their geographic location as the common frame of reference and
(2) to perform spatial analysis on this comprehensive data base.
The data sets used for the spatial analysis are well data, subsurface
fault data, hydrocarbon reservoir data, a high resolution Digital
Terrain Model(DTM) and LANDSAT satellite lineaments. The applications
of spatial GIS analysis techniques presented in this paper are:
- investigations of spatial relationship between
subsurface faults and well locations using buffer zones and
topological overlay,
- calculation of fault density and its implication
of subsurface fluid flow,
- modelling fluid flow using cost surfaces,
- spatial overlay between hydrocarbon reservoirs
and fault-related permeability distribution,
- determination of zones of high potential
of vertical fault-related aquifer connectivity by comparing
topographic lineaments extracted from a DTM with subsurface
faults and
- quality check of existing LANDSAT satellite
lineaments using a DTM.
Within Dutch water boards there is a growing
suspicion towards costly developments in Information Technology.
If this point of view becomes generally accepted, it will act
as a brake on the introduction of new GIS-applications. In order
to counterweight this, an investigation on costs and benefits
of new GIS-applications in Dutch water boards is carried out.
Developments are generally determined by environmental
circumstances. Information on the relevant influences within water
boards, together with information on modern attitudes towards
organisation development and IT/GIS, places these developments
in the righ perspective.
New applications within water boards also emerge
because of ongoing technological developments. Without going too
much in details, background information on important developments
in provided to be able to conceive how future applications might
work.
Water boards employ a manifold of automated
and manual systems on facilities information. An overview of all
relevant systems, followed by worked-out descriptions of possible
new GIS-applications, provides the basis for the research. As
expected from the general characteristics of water board’s
processes, emphasis is on communication and integration.
Since the decision on new application lies with
the water boards, they are invited to give the opinion on benefits
and priorities by means of questionnaires and interviews. This
phase also provides more in-depth information on their feelings
towards and possible new applications.
Since the objective is, to end up with costs
and benefits of new applications, the information on priorities
and benefits are completed with costs, to provide an overview
of applications which the water boards consider to be feasible
and necessary.
The intention is, to provide a more or less
general overview by gathering information from different water
boards. This approach automatically results in limitations because
of the limited scope of the information collected. All limitations
perceived are addressed, and if possible indications for improvement
and future research and provided.
This research project investigates the factors
which influence the successful implementation of a Geographical
Information System (GIS) in a secondary school. The factors generally
affecting the implementation of GIS in organisations are considered.
These are divided into four categories covering technical, financial,
organisation and user issues. The research approach and methods
are described and the research objectives defined. A case study,
Cheltenham College, an independent school, where GIS is being
used as a tool to assist in the teaching of geographical concepts
at Key Stage 3 and 4 of the National Curriculum for Geography
for England and Wales, is used to investigate the use of GIS in
secondary schools. The development and use of IT and GIS in the
case study are recorded. The results of research on the case study
are logged and analysed with respect to the previously described
categories of factors affecting implementation of GIS. These are
further analysed in the broader context of other educational and
other types of organisations. Finally, the future possible development
and use of GIS in schools in general and in Cheltenham College
are discussed.
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