Qatar Petroleum has a well-established and efficient network system managed by the IT Department. Leveraging the existing infrastructure, databases are implemented in a centralized computing environment with remote access over LAN/WAN. However, GIS applications require a lot of bandwidth and could easily choke the network with its extreme demand unless the applications are carefully tuned. Detailed studies were carried out to quantify the demand for bandwidth by the GIS system for MIC and several remedial measures adopted to deliver acceptable and consistent system performance. Spatial Database Engine (SDE) is found to provide enhanced system performance with bandwidth requirements as little as 1/5th of that without SDE. For serving data across the network QP has decided to exploit ESRIís native SDE technology.
Spatial Data Management Strategy
Strategies for data management were evaluated based on its ability for ease of data manipulation (edit, add or delete) provides adequate security, fast retrieval, and integration with other data, especially AutoCAD. In a corporate environment as diverse as QP any new system should strive to integrate and not replace an existing system. And, the strategy is designed for implementing an integrated and effective enterprise GIS system.
ArcSDE for coverages, ESRIís native technology, is utilized in MIC for integrating data between GIS and AutoCAD formats. With this technology it is not only possible to seamlessly integrate data formats but also to leverage its inherent improved network performance. AutoCAD clients can directly access spatial data stored in ArcSDE. The above capability has vastly improved the productivity and functioning of the GIS system in terms of faster application responses and by taking away the tied up time and resources by way of additional task of data conversion from GIS personnel.
The sewer database is organized by categorizing feature data into three categories (a) Foul Sewer (b) Surface Sewer and (c) Treated Sewers. Features within each category are independently registered with ArcSDE. Another aspect of ArcSDE that is conveniently exploited is its capability to recognize the feature once registered, irrespective of any changes made to it, until it is explicitly unregistered.
Categorization of sewer features has definite advantages but it is not without its own drawback. A disadvantage of this categorization is the repetition of the same features in more that one category, resulting in data redundancy at the database level. Pumping stations, for example, are common to all the three categories. However, given that there are advantages to feature categorization data redundancy is left to be managed by the customized application developed for MIC. The application tackles the issue by leaving a tag to each feature. Data duplication at the database level is thus avoided since there exists, as far as the database is concerned, just one feature.
One of the prerequisites to facilitate infrastructure planning and management is the access to data from different sources. And, with ArcSDE it is possible to access the following data sources, identified as important to MIC infrastructure planners.
- the National GIS database
- AutoCAD drawing files
- MICís own GIS database.
Data security is implemented at two levels, application and ArcSDE. At the application level users are allowed data access based on their intranet ID. Intranet IDís are captured from the network and compared against an encrypted list of authorized users. ArcSDE provides a combination of instance and password for data access. Authorized users are provided automatic access without the need to know the instance or password. They are thus unaware of the current logged in password and instance. True instance names are made difficult to figure out by introducing dummy names.
The decision support application developed by QP for MIC is aimed at assisting managers and senior staff in their planning and infrastructure development. Significance of the application cannot be underestimated, particularly, in the face of rapid urbanization MIC is preparing for within the next 5 years. Besides planning, it also permits monitoring the sewer system by providing access to images from CCTV, data manipulation and querying, and overlaying of satellite and aerial photographs together with GIS data for a better appreciation of the spatial layout of a region.
Sewer Infrastructure Planning
The application maintains two logical layers (1) Planning and (2) Existing. Planning layer maintains information of all features planned for but not existing. And, the existing layer holds all that is existing physically. Features already existing are moved by the application to the existing layer. Logical separation between features into layers is one way of managing the data effectively.
For planning a sewer infrastructure the primary prerequisites are the planned layout and the expected population for the region. MICís expansion plans are based on a Master Plan envisaged for the next 25 years. Infrastructure planning for the sewer system is based on this development blue print. The DSS application allows the blue print to be viewed in the system along with other data like contour and existing facilities both under and above the ground. Armed with this wealth of information the planner is able to plan the infrastructure starting with the pumping stations, then the sewer lines and the manholes. Assistance of aerial photographs can be sought in conjunction with elevation models by the planner in visualizing the topography of the area while locating pumping stations. Knowledge of existing facilities, crucial at the design stage and accessible from the application, helps to select the appropriate design especially while designing underground sewer facilities like sewer lines, distribution chambers, etc.
Management of MICís sewer system has been made a lot easier by the GIS system. It is now possible to keep track of maintenance schedules and resources, prepare detailed asset inventory, carry out inspections, create service requests and reports, etc.
GIS system has opened the portals to a wide range of data consumers within Qatar Petroleum and amongst similar local governments. It is now possible to share both data and information previously not possible for the common good of all. Development plans, once formally approved, can now be published and shared across various departments who may need to look at it for their own planning purposes. A case in point is the Telecommunications Department who may need to incorporate in their plans the planned expansion in MIC to be able to extend their basic services the new areas.
The GIS assisted sewer management system set up by ITD for MIC has an integrated and centralized spatial database that is registered with ArcSDE for coverage server for access by client applications over a LAN/WAN link. Decision support application developed by ITD has facilitated planners, with very little training in GIS, to automate their current tasks and to easily manipulate, query, and integrate data from different sources, including satellite and aerial photographs, and to prepare and print maps. The application maintains database security by restricting access only to authorized personnel.
The application has not only made easy the planning of sewer infrastructure systems but also for keeping track of maintenance schedules and resources, prepare detailed asset inventory, carry out inspections, create service requests and reports, etc.
To the community the single most benefit from the implementation of GIS in MIC has been the ability to share data across similar local governments under Qatar Petroleum.