The green roofs for reduction in the load on rainwater drainage in highly urbanised areas

Abstract

Rapid weather phenomena, particularly sudden and intense rainfall, have become a problem in urban areas in recent years. During heavy rainfall, urban rainwater drainage systems are unable to discharge huge amounts of runoff into collecting reservoirs, which usually results in local flooding. This paper presents attempts to forecast a reduction in the load on the rainwater drainage system through the implementation of green roofs in a case study covering two selected districts of Opole (Poland)—the Old Town and the City Centre. Model tests of extensive and intensive roofs were carried out, in order to determine the reduction of rainwater runoff from the roof surface for the site under study. The potential of the roofs of the buildings to make a green roof was also determined using geographical information systems (GIS), for a case study of two central districts of Opole. It proposed a methodology to determine the rainwater drainage system load reduction by making green roofs. The analyses carried out lead to the conclusion that, in the districts selected for the study, the execution of green roofs on 25% of the of buildings with the potential to implement this type of roof solution could reduce the load on the rain water system by a degree that protects the city area from local flooding.

Using multiple isotopes to identify sources and transport of nitrate in urban residential stormwater runoff

“…Increasing urbanisation worldwide has led to population explosion and changes in land use. Owing to the replacement of vegetation and permeable soil by impervious cover, a considerable amount of concrete floor constructed in urban areas causes stormwater runoff to easily collect pollutants (Al Mamoon et al, 2019;Muller et al, 2020;Silva and da Silva 2020;Kolasa-Wiecek and Suszanowicz 2021). Urban stormwater runoff containing large quantities of contaminants, such as organic matter, phosphorus, and N, is considered to be an important pathway for the delivery of contaminants to urban aquatic ecosystems (Li et al, 2016;Al Mamoon et al, 2019).…”

Experimental Analysis of the Influence of Seasonality on the Temperature Regime of Extensive Roofs in Central Europe

“…The growing population living in urban areas due to the level of affluence of large cities has resulted in several major problems, such as pollution and stormwater runoff during rainy seasons [1][2][3], air pollution [4], increased noise [5], global warming [6,7], and the emergence of the urban heat island effect [8], which is caused by a lack of vegetation sites. Urbanized environments with many paved areas and dense buildings cause an increase in temperature, especially at night, when the accumulated heat from these areas is radiated back into the environment [9].…”

Extensive Green Roofs: Different Time Approaches to Runoff Coefficient Determination

“…These changes disrupt the urban hydrological cycle (reducing the ability to intercept, store, and naturally infiltrate stormwater runoff) leading to a higher risk of urban flooding exacerbated by climate change [1], with catastrophic consequences in terms of casualties and economic losses [2]. On building roofs, rainwater is concentrated in volume and time, and the majority is typically directed to drainage systems, where it infiltrates into the ground or flows into sewers [3]. Urban green infrastructure (GI) can be used to reduce the amount of stormwater runoff entering drainage systems through the natural retention and absorption capabilities of vegetation and soils [1] and by promoting the infiltration of water through traditional structures.…”