Abstract:
Road runoff is a linear diffuse source of
pollution, with very specific characteristics. This study
intends to improve the understanding of road runoff
impacts in water bodies in Portugal. The chosen case
study is S. Domingos reservoir catchment. The study
analyzed land uses, the presence of pollution sources,
and gathered temporal water quality data and performed
site measurements and sample collection. The water
quality data for the reservoir was provided by the national
water quality monitoring system from the
Portuguese Water Institute. The parameters selected
were TSS, COD, NO3
−, Cl−
, and Cu. The results
obtained revealed that the presence of IP6 highway at
S. Domingos catchment affects the water quality; however,
the impacts are not significant due to the high
dilution effect of the reservoir volume. Agriculture, the
main land use of the catchment, is responsible for introducing
pollutants such as TSS, Cl−, COD, N, and P in
the local water streams and at the reservoir. TSS, COD,
and Cu are pollutants generated by the road. The success
of the study was very much dependent on the availability
of 12 years of historic water quality data for S.
Domingos reservoir, and the use of the moving average
method. Taking into consideration the high variability of
hydrological variables in Mediterranean climates, the concentration of pollutants in the water bodies must
always be assessed in a significant time period.
