Sewer-system analysis with the aid of a geographical information system
Geographical information system (GIS)-supported sewer-system analysis has major advantages over the use of traditional stand-alone sewer programs, especially with regard to establishing network topology, input of sewage contribution data, querying, displaying and mapping of results. This paper reports on the development of a GIS-supported sewer analysis software package using ArcView GIS. It supports all the stages of sewer-system analysis, viz. defining the topology of a sewer network, the specification of sewage flow contribution parameters, the allocation of sewage-contributing areas to sewer manholes, hydraulic analysis and displaying the analysis results. A sewer program has been developed for hydraulic analysis and written in Avenue, the internal programming language of ArcView. The sewer program is therefore fully integrated with ArcView, and all the functionality of ArcView is available during the sewer-system analysis. Such an integrated software package where the input data, sewer program, GIS and program results are all dynamically linked is the perfect environment for scenario management. The software package has already been successfully applied to the main sewer system of the Inner Cape Metropolitan Region (Inner CMR), as part of an M.Sc. thesis in Geography and Environmental Studies.