Study of the dynamics of surface runoff composition of the urban lands

Summary

The qualitative composition of surface runoff of urban lands is affected by significant fluctuations. Studying its dynamics, determining possible regularities and causes of these fluctuations can be conveniently carried out with the use of the mathematical apparatus of the time series analysis. The procedure of seasonal decomposition was applied to the time series of monthly dynamics with the annual periodicity of seasonal fluctuations with the help of the multiplicative model. The results of the quantitative chemical analysis of surface runoff at the «XXII Party Congress» outfall of the Samara municipality for 2004–2016 were used as benchmark data. As a result of the performed analysis the occurrence of the seasonal regularities of the surface runoff composition changes was determined. The seasonal indices of 15 effluent quality parameters were determined: BOD_full, suspended solids, mineralization, chlorides, sulfates, ammonium ion, nitrite ion, nitrate anion, phosphates (as phosphorus), total iron, copper, zinc, aluminium, oil products, and detergents (anionic). Based on the given seasonal decomposition of the time series the qualitative assessment of the effect of the trend, seasonal and random components on the unsteadiness of the surface runoff quality parameters was performed.

Key words

surface runoff , wastewater composition , outfall to the water body , multiplicative model , time series , seasonal decomposition , seasonal index