ASSESSMENT OF RAINFLOW REGULATION METHODS WITH THE PURPOSE OF PREVENTING UNDERFLOODING AND FLOODING OF URBAN AREAS

Abstract

Based on the analysis of the main causes of flooding and inundation of urban areas, methods of regulating rainwater runoff and criteria for evaluating their effectiveness have been systematized. All methods of rainwater regulation in urban areas are divided into two groups: storage and filtering. Accumulative ones include: change in the shape of the surface of coatings (indentations and protrusions, increased roughness, porous bulk layers on them); small containers (tanks, cisterns); reservoirs; open water bodies (ponds, biological ponds, swamps). Filtering methods include: areas with natural soil coverings (lawns, vegetated strips, rain gardens); filtration facilities (trenches, infiltration basins); "green" roofs of buildings and structures; water-permeable improved coatings (porous concrete, asphalt, lawn grates, gravel paths).Seven main and one additional criteria for assessing technological, urban planning, environmental and economic feasibility have been determined. The main criteria include: rainwater retention conditions; duration of rainwater retention; the ability to pre-clean rainwater runoff; regeneration conditions; the need for additional areas for buildings; increase in groundwater levels in the places where structures are installed; cost-effectiveness (need for additional capital investments and (or) operational costs). An additional (8th) criterion for evaluating the effectiveness of the specified methods is the regulatory ability of structures to retain the calculated volumes of precipitation or formed runoff (in percentages until complete retention).It was established that the most appropriate is a combination of rainwater regulation methods. It provides for a combination of various methods of regulating rainwater runoff, the types and effectiveness of which are used in specific areas determined by a group of proposed factors. The final determining factor is the economic capacity of the city to implement the considered methods.