scholarly journals Hyperspectral Monitoring of Green Roof Vegetation Health State in Sub-Mediterranean Climate: Preliminary Results

Sensors ◽  
2017 ◽  
Vol 17 (4) ◽  
pp. 662 ◽  
Author(s):  
Patrizia Piro ◽  
Michele Porti ◽  
Simone Veltri ◽  
Emanuela Lupo ◽  
Monica Moroni
Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1368 ◽  
Author(s):  
Monica Moroni ◽  
Michele Porti ◽  
Patrizia Piro

The combination of an appropriate design and careful management of green infrastructures may contribute to mitigate flooding (stormwater quantity) and pollutant discharges (stormwater quality) into receiving water bodies and to coping with other extreme climate impacts (such as temperature regime) on a long-term basis and water cycle variability. The vegetation health state ensures the green infrastructure’s effectiveness. Due to their remarkable spatial and spectral resolution, hyperspectral sensing devices appear to be the most suited for green infrastructure vegetation monitoring according to the peculiar spectral features that vegetation exhibits. In particular, vegetation health-state detection is feasible due to the modifications the typical vegetation spectral signature undergoes when abnormalities are present. This paper presents a ground spectroscopy monitoring survey of the green roof installed at the University of Calabria fulfilled via the acquisition and analysis of hyperspectral data. The spectroradiometer, placed on a fixed stand, was used to identify stress conditions of vegetation located in areas where drought could affect the plant health state. Broadband vegetation indices were employed for this purpose. For the test case presented, data acquired agreed well with direct observations on the ground. The analyses carried out showed the remarkable performances of the broadband indices Red Difference Vegetation Index (Red DVI), Simple Ratio (SR) and Triangular Vegetation Index (TVI) in highlighting the vegetation health state and encouraged the design of a remote-controlled platform for monitoring purposes.


2010 ◽  
Vol 45 (8) ◽  
pp. 1890-1904 ◽  
Author(s):  
R. Fioretti ◽  
A. Palla ◽  
L.G. Lanza ◽  
P. Principi

2020 ◽  
Vol 12 (23) ◽  
pp. 10178 ◽  
Author(s):  
Behrouz Pirouz ◽  
Stefania Anna Palermo ◽  
Mario Maiolo ◽  
Natale Arcuri ◽  
Patrizia Piro

Electrical and energy production have a noticeable water footprint, and buildings′ share of global energy consumption is about 40%. This study presents a comprehensive experimental analysis of different thermal impacts and water consumption of green roofs in a Mediterranean climate. The study aims to investigate the use of water directly for green roofs and reduce the water footprint of energy in summer and winter due to its thermal impacts. The measurements were carried out for an extensive green roof with an area of 55 m2 and a thickness of 22 cm, and direct water consumption by a green roof and direct and indirect water consumption by cooling and heating systems were analyzed. According to the analysis, in summer, the maximum roof temperature on a conventional roof was 72 °C, while under the green roof it was 30.3 °C. In winter, the minimum roof temperature on a conventional roof was −8.6 °C, while under the green roof it was 7.4 °C. These results show that green roofs affect energy consumption in summer and winter, and the corresponding thermal requirements for the building have a water footprint regarding energy production. In summer, the thermal reduction in the water footprint by a green roof was 48 m3 if an evaporative air conditioner is used and 8.9 m3 for a compression air conditioner, whereas the water consumed in the green roof was 8.2 m3. Therefore, using water directly in the green roof would reduce the energy consumption in buildings, and thus less water has to be used in power plants to provide the same thermal impact. In winter, green roofs′ water consumption was higher than the thermal water footprint; however, there is no need to irrigate the green roof as the water consumed comes from precipitation. This experimental analysis determines that in the Mediterranean climate, green roofs allow the achievement of the same thermal conditions for buildings in both summer and winter, with a reduction in water consumption.


2018 ◽  
Vol 8 (12) ◽  
pp. 2497 ◽  
Author(s):  
Antonio Vestrella ◽  
Carmen Biel ◽  
Robert Savè ◽  
Flavia Bartoli

Green roofs provide a number of environmental advantages like increasing urban biodiversity, reducing pollution, easing burdens on drainage systems, and lowering energy costs thanks to thermal insulation. Frankenia laevis, Dymondia margaretae and Iris lutescens were tested in a green roof installation. For all three species, we assessed two minimal irrigation treatments and one rain-fed treatment to resemble Mediterranean climate conditions analyzing the thermal and hydrological performance of all three species and their substrates through an evaluation of green cover, mortality, and biomass. The most influential factors registered for all three species are the relationship between air and water in the substrate and the interaction between green cover and substrate, respectively, for summer and winter seasons. In particular, D. margaretae preserved more water in its substrate than the other species both in summer and winter and after each rainfall event. F. laevis registered the highest level of variation in terms of substrate water content and of rainwater retention. I. lutescens achieved low hydrological performance, a limited amount of green cover, and slow growth. Our results suggest the absolute need of additional irrigation, managed in accordance with specific functional objectives, for all three species analyzed under Mediterranean conditions and different water regime.


Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2030
Author(s):  
Mansoureh Gholami ◽  
Alberto Barbaresi ◽  
Patrizia Tassinari ◽  
Marco Bovo ◽  
Daniele Torreggiani

In urban areas, a considerable proportion of energy demand is allocated to buildings. Since rooftops constitute one-fourth of all urban surfaces, an increasing amount of attention is paid to achieving the most efficient shapes and component designs compatible with every climate and urban context, for rooftops of varying sizes. In this study, three types of rooftop technologies, namely insulated, green roof, and rooftop greenhouse, are evaluated for energy and thermal performance using computer simulations. Water surface exposure, absorption, and intrusion are the three important factors in the calculation of hygrothermal models that impact energy consumption and building envelope performance; however, a few studies are specifically focused on providing realistic results in multi-dimensional hygrothermal models and the assessment of the impact of moisture in roofing solutions. This paper aims at evaluating the performance of three different roofing technologies through a two-dimensional hygrothermal simulation in software WUFI. To accomplish this, a precise localized microclimate model of a complex urban context on the scale of a neighborhood was employed to evaluate the cooling and heating loads of the buildings, the impact of the water content in the green roof on the thermal behavior of the roof surface, and the feasibility of designing a building with nearly zero cooling needs. A two-story building in the city center of Bologna, Italy is modelled. Simulation results have shown that during the cooling period, the performance of the designed rooftop greenhouse is the most effective by 50% reduction in cooling loads. Besides, the impact of moisture in green roofs has been detected as a negative factor for thermal and energy performance of the building in the Mediterranean climate. The results ultimately highlighted the capability of passively-designed rooftop greenhouses to create a building with nearly zero cooling needs.


2017 ◽  
Vol 76 (5) ◽  
pp. 1081-1089 ◽  
Author(s):  
Cristina M. Monteiro ◽  
Cristina S. C. Calheiros ◽  
Paulo Palha ◽  
Paula M. L. Castro

Green roof technology has evolved in recent years as a potential solution to promote vegetation in urban areas. Green roof studies for Mediterranean climates, where extended drought periods in summer contrast with cold and rainy periods in winter, are still scarce. The present research study assesses the use of substrates with different compositions for the growth of six aromatic plant species – Lavandula dentata, Pelargonium odoratissimum, Helichrysum italicum, Satureja montana, Thymus caespititius and T. pseudolanuginosus, during a 2-year period, and the monitoring of water runoff quality. Growing substrates encompassed expanded clay and granulated cork, in combination with organic matter and crushed eggshell. These combinations were adequate for the establishment of all aromatic plants, allowing their propagation in the extensive system located on the 5th storey. The substrate composed of 70% expanded clay and 30% organic matter was the most suitable, and crushed eggshell incorporation improved the initial plant establishment. Water runoff quality parameters – turbidity, pH, conductivity, NH4+, NO3−, PO43- and chemical oxygen demand – showed that it could be reused for non-potable uses in buildings. The present study shows that selected aromatic plant species could be successfully used in green roofs in a Mediterranean climate.


2002 ◽  
Vol 12 (03n04) ◽  
pp. 225-230
Author(s):  
JUAN A. ASPIAZU F. ◽  
JOSE LOPEZ M. ◽  
JESUS RAMIREZ T. ◽  
PEDRO VILLASEÑOR S. ◽  
ALICIA GALNARES DEL C. ◽  
...  

It is well known that green roof systems are being used to improve the environment by reducing the summer temperatures inside the houses and to capture atmospheric contaminants. The Universidad Autónoma de Chapingo had begun a project to test the latter possibility in Mexico City, were some roofs were covered with the plant Sedum praealtum L. By PIXE analysis, metal concentrations were determined in ashes of the leaves and stems. The concentrations were compared with those of the substrata and plantations grown in a greenhouse, which were used as a reference. Preliminary results are presented.


Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1378 ◽  
Author(s):  
Stefania Anna Palermo ◽  
Michele Turco ◽  
Francesca Principato ◽  
Patrizia Piro

In urban water management, green roofs provide a sustainable solution for flood risk mitigation. Numerous studies have investigated green roof hydrologic effectiveness and the parameters that influence their operation; many have been conducted on the pilot scale, whereas only some of these have been executed on full-scale rooftop installations. Several models have been developed, but only a few have investigated the influence of green roof physical parameters on performance. From this broader context, this paper presents the results of a monitoring analysis of an extensive green roof located at the University of Calabria, Italy, in the Mediterranean climate region. To obtain this goal, the subsurface runoff coefficient, peak flow reduction, peak flow lag-time, and time to the start of runoff were evaluated at an event scale by considering a set of data collected between October 2015 and September 2016 consisting of 62 storm events. The mean value of subsurface runoff was 32.0% when considering the whole dataset, and 50.4% for 35 rainfall events (principally major than 8.0 mm); these results indicate the good hydraulic performance of this specific green roof in a Mediterranean climate, which is in agreement with other studies. A modeling approach was used to evaluate the influence of the substrate depth on green roof retention. The soil hydraulics features were first measured using a simplified evaporation method, and then modeled using HYDRUS-1D software (PC-Progress s.r.o., Prague, Czech Republic) by considering different values of soil depth (6 cm, 9 cm, 12 cm, and 15 cm) for six months under Mediterranean climate conditions. The results showed how the specific soil substrate was able to achieve a runoff volume reduction ranging from 22% to 24% by increasing the soil depth.


Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2016 ◽  
Author(s):  
Gomes ◽  
Silva ◽  
Valadas ◽  
Silva

Green roof energy performance is still a challenging topic, namely in a Mediterranean climate since it depends on building characteristics, roof type, and also on climatic conditions. This paper evaluates green roof buildings’ energy needs and use in a Mediterranean climate. An experimentally calibrated numerical model was used to perform a parametric analysis and identify the influence of key parameters in heating and cooling energy needs, as well as annual energy use. The vegetation height, the soil depth, and LAI (leaf area index) were identified as the key parameters. The irrigation levels were also crucial for the energy performance of green roofs, particularly during the summer period and in a Mediterranean climate. Heating energy needs were mainly associated with soil depth due to higher thermal resistance, whereas cooling energy needs depended mostly on LAI, which influenced evapotranspiration and shading effects. A reduction of soil depth from 1.0 m to 0.1 m increased winter energy needs by up to 140%, while low values of LAI increased cooling energy needs up to 365%. Annual energy use in a Mediterranean climate showed a higher dependence on soil depth, with oscillations of up to 115%, followed by LAI and vegetation height. Finally, irrigation levels impacted the annual energy use more significantly for lower watering flow rates. Reductions of about 500% were obtained when changing watering flowrates from 0 mm/day to 6 mm/day in intensive green roofs. Since green roofs with native species expect low values of watering, this may increase their cooling energy needs.


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