The INCA-Pathogens model: An application to the Loimijoki River basin in Finland.
Good hygienic quality of surface waters is essential for drinking water production, irrigation of crops and recreation. Predictions of how and when microbes are transported by rivers are needed to protect downstream water users. In this study we tested the new process-based INCA-Pathogens model in the agricultural Loimijoki River basin (3138km2) in Finland, and we quantified ecosystem services of water purification and water provisioning for drinking and recreation purposes under different scenarios. INCA is a catchment scale process based model to calculate pollutant transfer from terrestrial environment and point sources to the catchment outlet. A clear gradient was observed in the numbers of faecal coliforms along the River Loimijoki. The highest bacterial counts were detected in the middle part of the main stream immediately after small industries and municipal sewage treatment plants. In terms of model performance, the INCA-Pathogen model was able to produce faecal coliform counts and seasonality both in the low pollution level sampling points and in the high pollution level sampling points. The model was sensitive to the parameters defining light decay in river water and in soil compartment, as well as to the amount of faecal coliforms in the manure spread on the fields. The modeling results showed that the number of faecal coliforms repeatedly exceeded 1000 bacteria 100ml-1. Moreover, results lead to the following conclusions: 1) Climate change does not cause a major threat to hygienic water quality as higher precipitation increases runoff and causes diluting effect in the river, 2) Intensification of agriculture is not a threat as long as animal density remains relatively low and environmental legislation is followed, 3) More intensive agriculture without environmental legislation causes a threat especially in tributaries with high field percentage and animal density, and 4) Hygienic water quality in the River Loimijoki can best be improved by improving sewage treatment. We conclude that this catchment scale model is a useful tool for addressing catchment management and water treatment planning issues.
Finnish Environment Institute (SYKE), Mechelininkatu 34a, FI 00250 Helsinki, Finland. Electronic address: katri.rankinen@ymparisto.fi.
K
K
Rankinen
University of Oxford, School of Geography and the Environment, South Parks Road, Oxford, OX1 3QY, UK.
D
D
Butterfield
Deltares, Princetonlaan 6-8, 3584 CB Utrecht, P.O. Box 85467, 3508 AL Utrecht, The Netherlands.
M
M
Faneca Sànchez
European Commission Joint Research Centre (JRC), via Enrico Fermi 2749, 21027 Ispra, VA, Italy.
B
B
Grizzetti
University of Oxford, School of Geography and the Environment, South Parks Road, Oxford, OX1 3QY, UK.
P
P
Whitehead
National Institute for Health and Welfare (THL), Water and Health Unit, Neulaniementie 4, FI 70700 Kuopio, Finland.
T
T
Pitkänen
Natural Resources Institute Finland (Luke), Tietotie 4, FI 31600, Jokioinen, Finland.
J
J
Uusi-Kämppä
University of Oxford, School of Geography and the Environment, South Parks Road, Oxford, OX1 3QY, UK.
H
H
Leckie
D000383:Agriculture; D060766:Drinking Water / Q000382:microbiology*; D004755:Enterobacteriaceae / Q000302:isolation & purification*; D004784:Environmental Monitoring / Q000379:methods*; D005387:Finland; D008962:Models, Theoretical; D045483:Rivers / Q000382:microbiology*; D062065:Wastewater / Q000382:microbiology*; D018508:Water Purification; D014881:Water Supply
D060766:Drinking Water; D062065:Wastewater
Catchment scale; Faecal bacteria; Hygienic quality; Mathematical modelling; Water quality monitoring