Assessment of the Sources of Pollution and of Surfaces Suitable for Bioretention Systems in Different Sites in Terms of Land Use

Abstract

The knowledge of the rainwater runoff pollution sources and the flow pattern is essential in evaluation of storm water management options. The aim of the study was to identify the pollution sources, to establish the position of these sources and runoff pathways of the polluted rainwater; identify the areas where can be implemented the bioretention systems; the size analysis of the surfaces suitable for bioretention systems implementation based on location and land use. The study included four types of urban sites: commercial, industrial, low density residential and high density residential. The methodology of identification of diffuse pollution sources in the studied sites used field observation methods, imagery and GIS software. To properly identify the pattern of the stormwater runoff, field observations were made during the days with precipitation, between March 2012 and August 2014. For a clear results, were observed precipitations and runoff for each season separately, including snowfall (was followed water leakage pattern from melting snow). Precipitations with varying degrees of intensity were followed. The sources of diffuse pollution of stormwater runoff were determined on the basis of land use types. The results show that the diffuse sources of contamination of rainwater runoff are characteristic of the studied areas in close relationship with the land use type. The evaluation of suitable surfaces for bioretention implementation in Cluj-Napoca, by studying these four representative areas, shows that in all areas, regardless of the land use types, the surfaces are available for the implementation of these systems. The studied issue related to diffuse pollution sources and areas suitable for bioretention systems does not restrict and recommends their implementation.