The model documentation summarizes the data, variables and assumptions required to capture how water purification services are provided across landscapes in Alberta. Water purification in this context captures water quality and quantity. Water purification services act by absorbing or filtering pollutants or by preventing erosion. The processes related to these services may take place during overland flow, during infiltration and leaching, during ground water passage, or in wetlands or water bodies.
Ecosystem processes involved in water purification services range from physical processes, such as vegetation preventing erosion, to biochemical processes by microorganisms in soil, water or wetlands. The benefit of the service consists inter alia of decreasing water treatment costs, increasing the aesthetic value of water for swimming and tourism, and supporting fish stocks harvested for commercial or recreational purposes.
The water purification services in the model capture many of the physical processes associated with how vegetation interacts with overland flow, water bodies, and wetlands, etc. The current model, however, does not capture ground water passage or related interactions, nor does it fully depict the biochemical processes that result in the transport and deposition of nitrogen and phosphorus with overland flow. Future research and modelling is required to capture these processes as they relate to water purification services.