Green roofs are one of the method of recovering green space in urban are-as. They are also effective in improvement of air quality and local climate as well as play an important role in thermal insulation of buildings. The most important role they play in urban areas is rain water retention and delaying of the runoff. The main goal of the research was to estimate potential influence of the green roof substrate on runoff water quality. Preliminary results show increase of the con-centration of phosphates and total solids in leachate. Mean concentration of solids in intensive roof substrate leachate amounted 231 mg dm-3 and in extensive sub-strate leachate 274 mg dm-3, comparing to concentration 6-7 mg dm-3 in simulated rain. Phosphorus concentration in intensive and extensive substrate runoff amounted 0,112 mgPO4-P dm-3 and 0,126 mgPO4-P dm-3 respectively. Phosphorus concentration in simulated rain amounted 0,056 mgPO4-P dm-3. Even if the concentrations in substrate leachate are low, phosphorus can still be an important factor influencing green roofs runoff receiver quality. ...
In the cities, the temperature may be a few or even several degrees higher than the surrounding area. The result is called" urban heat island effect" which is due to heating of the surface of concrete, asphalt and steel. One of the solutions that can help reduce this phenomenon are green roofs. The aim of the study was the analysis of temperature changes of different roof surfaces (board, intensive roof substrate without plant cover, substrate covered with plants (shrubs - tawuły). The study was conducted on the roof of the building of the Faculty of Modern Languages, University of Warsaw. The measurement was performed using the FLIR SC620 thermal imaging system. The study showed that the smallest differences in average temperature between the surface covered with vegetation and a terrace amounted to 1,9oC (in the morning), while the largest reached 16 °C. The measurements made on the substrate without plants showed that the average radiation temperature is between the average temperatures from the terrace and shrubs. The results were discussed with the meteorological data (air temperature, wind speed). ...
Soilless cultivation of tomatoes in the greenhouse is a source of waste in form of mineral wool polyethylene. Utilisation of mineral wool waste originating from horticulture is still unresolved and rises a lot of controversy The aim of the study is to evaluate the possibility of using mineral wool waste in the construction of a green roof. To find the answer, physical properties, i.e. water absorption, water capacity and leachability were assessed for fresh mat and mineral wool waste. Preliminary assessment of pollutants leaching from mineral wool waste was also performed. It was found that the physical properties of the used mats are different from those of the input material. The content of phosphorus in leachate from used mineral wool derived from greenhouse cultivation excludes its use as a material for green roofs construction, if the runoff is discharged into water bodies. ...
One of the main problems of urbanization is the continuous growth of sealed surfaces. Impermeable surfaces i.e. roofs, roads or pavements have dominated land cover, increasing surface runoff and limiting groundwater runoff, often contributing to increased flood risk. The practice of many countries has shown that green roofs are one of the solutions to the problem of rainwaters on the urban areas. The aim of the study was to assess the retention ability of three green roofs of extensive type with different substrate composition (two mineral-organic mixtures, one mineral mixture). The research was carried out at the Water Centre of the Warsaw University of Life Sciences in Warsaw (Ursynów district) in the period from June to November in 2016. The obtained results were compared with observation of the reference model - bituminous roof. Model studies have shown that green roofs retained water in the range from 9.5 mm to 67.1 mm. The average runoff coefficients for green roof types in the period from June to November in 2016 were from 0.31 to 0.33. The obtained results showed slight differences in outflows with different substrates. During high rainfall, the differences in the runoff between the green roofs and the reference roof ...
