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 ...
Soil microrelief is one of the factors affecting wind and water erosion process. Spatial variability of soil surface (microrelief) influences initiation of the surface runoff and water flow mainly through depressions, where the runoff is delayed and infiltration increases owing to the interception of the flowing water. The research was conducted to assess the changes of relief of two soils (sandy loam and fine sand) under the influence of rainfall in a model experiment. The soil microrelief was determined by means of a contactless 3D scanner using the effect of line distortion as light beam illuminating the object surface (so called Moire pattern). On the basis of obtained results, maps of the differences in the scanned surface elevations were plotted in ArcGIS programme and the soil losses volume was computed. RR indicator calculated for sandy loam was decreasing with increasing depth of simulated rainfall. No such dependence was observed for loose sand. ...
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. ...
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). ...
This paper examines the changes in stocks of water in clay soils against precipitation and changes in the groundwater table. The study was conducted during the summer period (May-September) in 2001 and 2002. According to the Kaczorowska`s criteria (1962) the year 2001 was very wet, and the 2002 - average. In 2001, ground water table was at a depth of 0 to 190 cm below ground surface level, and in 2002, from 50 cm to 150 cm below the surface. Water storages in the root zone (0-35 cm) developed in 2001 at the level of 100 to 125 mm, in 2002, from 88 mm to 122 mm. ...
The distribution of precipitation is a particularly important factor in periods of critical crop plants which the greatest demand for water. At this work a number of meteorological characteristics associated with precipitation got in Puczniew station in years 1972-2002 were analysed: annual and six-month sums of precipitation; changeability of sums of annual and six-month precipitation (with using the division of years and months on extremely dry, very dry, dry, average, wet, very wet and extremely wet surface); number of days with precipitation (in periods < 10 mm, 10.1 -20 mm, 20,1-30,0,0 mm, 30.1-40.0 mm and above 60.0 mm); appearing of rainless periods. In examined 31-years from1972 to 2002 the averaged annual sum of falls in Puczniew amounted to 540.7 mm. From performed analysis we obtained none of years extremely dry and particularly humid: 2 years stayed ranked to dry, 27 - up to averages, 2 - to humid. Years 1983 and 1989 were dry, however year 1977 was humid and 2001 very humid. On average within one year it appeared about 3 rainless periods, appearing mostlyin summer year (59% of cases), and dominating droughts have lengths from 9 up to 17 days (90%). ...
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. ...
Air pollution, noise, omnipresent traffic and the accompanying stress make an adverse effect on human life in the city. In addition, buildings and related umpermeable surfaces, enhance the urban heat island effect and cause problems with the management of rainwater. Therefore, modern housing developments must meet the challenge of ensuring a high quality of life for residents. This effect can be achieved by putting on the green, including green roofs, and the construction of ponds in the form of rainwater management systems. Another challenge is to maintain the quality of water in the reservoir. The paper presents the results of two reactive materials laboratory scale tests, for their use in order to maintain the level of phosphorus in the water. According to the FLL guidelines (2011) for swimming ponds, phosphorus concentration below 0.01 mg/L will provide transparent and visually attractive water. Studies have shown that the opoka turned out to be more effective sorbent for phosphorus than dedicated to this goal commercial product FerroSorp®. ...
The influence of working of the unused sub-irrigation system on air-water conditions of peat-moorsh soil is presented in this paper. Measurements of moisture content, ground and open water levels were carried out in period July-September 2013. Top layers of the analyzed peat soil were characterised by wide range of moisture content changes. The analyzed part of the sub-irrigation system ditches and the river drain flowing through the analysed plot showed the drainage character. The ground water levels on the plot used as a meadow were observed higher to the soil surface than in case of abandoned part of peatland situated behind the river. ...
The most of the on site wastewater treatment systems in Poland discharges treated effluent to the soil. The goal of phosphorus (P) reduction from dispersed sources of pollution can be achieved by application of P reactive materials in the construction of wastewater infiltration systems. Two P reactive materials were tested in this study: Polonite® in grains of 26 mm and lightweight aggregate Leca® in grains of 410 mm. Apparent P sorption capacity was assesed on 40.9 mg·g-1 (Polonite®) and 5.1 mg·g-1 (Leca®). Both materials sorbed P-PO4 very fast, after 15 min over 90% of P was removed from solution and wastwater. Wastewater used in this study came from the outlet from the septic tank of on site septic system. P-PO4 solution was prepared from KH2PO4 and the tap water. In the small column experiment, four collumns (2 filled with Polonite® and 2 filled with Leca®) were fed with wastewater and P-PO4 solution in hydraulic loadings of 3040 dm3·m-2·d-1. All the columns removed significant amounts of P from both solution and wastewater with the reduction between 28.3% and 72.5%. The mean P-PO4 effluent concentrations ranged from 1.21 mg·dm-3 to 7.12 mg·dm-3. The best overall performance was achieved by the Polonite® fed ...
