Reports and Papers

Fedra, K. and Jamieson, D.G.

An object-oriented approach to model integration: a river basin information system example. In: Kovar, K. and Nachtnebel, H.P. [eds.]: IAHS Publ. no 235, p669-676.

A practical example

To demonstrate the interaction of the various objects in WaterWare and their linkage to the GIS level, consider the following example of a typical waste management problem. It is, however, embedded into a broader water resources management context. For a given subsection of the river network, severe water quality problems are observed due to massive BOD load from industrial, domestic, and agriculture sources, aggravated by reduced flow due to massive abstractions for irrigation purposes.

In terms of the components of WaterWare, the ultimate decision problem is supported by the waste load allocation model, a post-processor of the water quality models. Alternative treatment strategies or technologies, each with investment and operating costs are required for each of the sources considered. Sources can include both point sources such as treatment plants or diffuse sources such as intensively used agricultural areas, each represented by the corresponding RiverBasinObject. They are used together with the simulation model results to find a cost efficient strategy to meet water quality targets.

Input to the water quality model (the model's ScenarioObjects) comes in part from the RiverNetworkObjects, in part from the Water Resources Model that provides the flow regime for a range of demand and supply conditions. The Water Resources Model, in turn, uses its own ScenarioObjects and their RiverNetworkObjects that supply the available flows as well as the water demand in the network. The dominant agricultural water demand can be computed by models such as the Irrigation Water Demand Model, and, where the conjunctive use of surface and groundwater is important, by the groundwater resources model. The available flow for the subcatchments feeding into the network comes either from the observation time series of an observation station (a RiverBasinObject), or is computed by the rainfall-runoff model. The latter, in turn, uses the information from a subcatchment object (which provides geometry and land use) together with the time series for precipitation and temperature from one or several hydrometeorological observation stations.