GEOGRAPHIC INFORMATION SYSTEM
A Geographic Information System (GIS) combines hardware,
software, geographic data, and experienced personnel to
support the collection, storage, display and analysis of
spatially referenced data. GIS applications can help identify
trends in water main breaks to prioritise pipe replacement
and rehabilitation projects. Such projects are typically
analysed using a variety of weighted criteria such as pipe
material, diameter, age, main break history, water quality, and coordination with other public works projects. These criteria can be represented spatially in a GIS and associated with the pipe inventory. Utilities can then decide what improvements and when to make them.
GIS can help identify trends in leakage and water quality events and relate this information to the infrastructure and its conditions. It can also aid in localising and isolating leakage and water quality incidents and determining their root cause. When coupled with hydraulic modelling, GIS can support forward and back-tracing of leakage and water quality issues.
Once established, a GIS can be enhanced to serve as a critical link for meeting ongoing data maintenance requirements, supporting numerous data analysis/ reporting activities, and interfacing with other applications.
The benefits of implementing GIS generally fall into five basic categories:
1. Cost savings resulting from greater efficiency: GIS results in greater efficiency, associated either with ongoing operations (i.e., labour savings from automating or improving a workflow) or improvements in operations.
2. Better decision making: Primarily related to the location of network issues such as leakage and burst detection and water quality incident reports.
3. Improved communication: GIS-based maps and visualisations greatly assist in understanding situations. They are a new language that improves communication between different teams, departments, disciplines, professional fields, organizations, and the public.
4. Better geographic information recordkeeping: Many organisations have a primary responsibility for maintaining authoritative records on the status and change of geography (i.e. geographic accounting). Physical geography examples include environmental measurements, water flows, and a host of geographic accountings. GIS provides a strong framework for managing these types of systems.
5. Managing geographically: System operators and administrators use GIS information to communicate. These products provide a visual framework for conceptualising, understanding, and prescribing action.
Any data already in map form can be incorporated into a GIS system. This includes network topography such as the location of reservoirs, pumps, valves, distribution mains, household connections as well as information about the surrounding terrain, elevation, etc. Digital or computerised data such as satellite imagery can also be entered into GIS. Maps must be scanned or converted into digital information. GIS can also include data in table form, such as population information. GIS technology allows all these different types of information, regardless of their source or original format, to be integrated into a single map once it is converted to scale.
When current data on assets (e.g. positions of valves, pump settings) and results from sensors and monitors are collected and stored in a central database application (e.g. operational historian or SCADA database), this information can then be linked to associated objects in the GIS, provided the systems have a common interface for exchange of information such as Open Database Connectivity (ODBC).