As an effective energy-saving measure, green roofs significantly improve the thermal environment of buildings by covering the roof with vegetation and soil. This paper compares the thermal transfer performance of concrete roofs and green roofs under different temperature conditions. First, a uniaxial compression discrete element method (DEM) was used to calibrate the mesoscopic parameters of concrete, ensuring an accurate representation of concrete properties. The results indicate that green roofs have significant insulation effects under high-temperature conditions in summer. After being exposed to high temperatures for 5 h, the temperature of the green roof was 23.4 degrees Celsius lower than that of the ordinary concrete roof. In addition, different initial temperatures of the model also have a certain impact on heat transfer. The higher the initial temperature, the slower the temperature increase under high-temperature conditions. In winter, the green roof significantly delays the cooling at the top of the building, demonstrating excellent thermal insulation performance. The maximum temperature difference compared with the concrete roof is 8 degrees C. Finally, there is an exponential relationship between the thermal resistivity of the green roof and the temperature. In conclusion, green roofs have significant energy-saving and environmental protection value.

Evapotranspiration (ET) is an important water budget term for understanding the recovery of stormwater retention in green roof systems (GRs). However, ET evaluations, particularly in full-scale GRs, remain challenging. This study investigated ET dynamics within a GR in the City of Pittsburgh, USA, using a water balance based on continuously monitored soil moisture from moisture sensors over 15 months. Results suggest under well-watered soil conditions, daily moisture loss correlated with solar radiation, temperature, and humidity, in decreasing order of correlation strength, while wind speed had limited effects. Compared to sensor-informed moisture loss (using moisture-based water balance), the Hargreaves and FAO-56 Penman-Monteith equations predicted cumulative ET that was 1.8 and 2.1 times higher, respectively. When soil moisture declined and approached the temporary wilting points, a noticeable reduction in daily moisture loss was observed. This suggests the necessity of using a water stress coefficient alongside a crop coefficient to represent actual ET based on FAO-56 Penman-Monteith estimates. Seasonal crop coefficients from dominant native plant species present at our monitored location, eastern bluestar (Amsonia tabernaemontana) and creeping woodsorrel (Oxalis corniculata), had mean values of 0.48, 0.62, and 0.65 for fall, spring, and summer, respectively. The impact of water stress on ET could be characterized by a linear relationship with moisture content. Our results highlight the importance of soil moisture in regulating ET processes and demonstrate the utility of soil moisture data for evaluating ET in GRs and informing irrigation practices.

Ongoing urbanisation and climate change threaten urban green (UG) spaces in Lima, exacerbated by conventional design and management methods. Extensive green roofs (GRs) are a promising alternative in Lima's context as they provide numerous benefits and are adapted to arid conditions. This study aimed to develop sustainable GRs in Lima by using the Lomas ecosystems as a habitat template. We analysed abiotic conditions and plant traits of Lomas communities and compared them with those of GRs. We compared species composition and edaphic properties from five Lomas around Lima with those of arid GR systems. Lomas and GR species were further classified into functional groups based on their functional traits. Amancaes, Lachay and Villa Maria del Triunfo (VMT) have soils with similar characteristics as arid GRs, and the most suited Lomas species were found there. The 'herb functional group', consisting of herbs with succulence and clonal capacity, may be suitable for GRs due to arid adaptations and creeping and clumping growth patterns. Given the endangered status of several Lomas species within this group, introducing them to GRs in Lima offers a conservation opportunity, helping their survival and establishing urban complementary habitats. Shrub species such as Heliotropium, Atriplex, Croton, and Trixis are the most frequent shrubs in Lomas and are crucial for preserving the structure and biodiversity of the ecosystem. However, the 'shrub functional group' may be better suited for semi -intensive GRs due to their deeper root systems and erect growth. The habitat template approach can aid biodiversity conservation by incorporating threatened and endemic Lomas species into GR systems.

In recent years, the rapid development of the world's economy has led to the large-scale development and utilization of ecological resources on the earth, due to which the ecological environment has been continuously and seriously damaged, resulting in the waste of resources, soil erosion, land desertification, etc. To avoid further damage to the ecological environment and ecological resources, improve the utilization rate of ecological resources, and ensure the sustainable development of human society, it is necessary to evaluate the ecological environment. In this study, we collected the required data using the Delphi method and remote sensing technology. Secondly, the green Olympic building evaluation system (which refers to the CASBEE method in Japan) was used to evaluate the impact of green roofs on architectural design and the urban ecological environment. Third, a deep learning (DL)-based hybrid model, which consists of a convolutional neural network (CNN) and long-short-term memory (SLSTM), known as CNN-LSTM, was used to evaluate the impact of green roofs on urban ecology and building architectural design. The influence of thermal comfort on the indoor environment of green roof buildings was studied. For experimentation, six samples of Shanghai Thumb Plaza, Splendid Tesco Point, Chaoshan Yuan Hotel, Green Management Office, Huangpu District Domestic Waste Transfer Station, and Changning District Fuxin Slaughterhouse were selected as evaluation objects, and the effect of green roofs on building design and urban ecology was evaluated from six levels: ecological, ornamental, safety, functional, social, and economic. Both the CASBEE and DL-based methods, CNN-LSTM, performed well and increased the evaluation results to some extent. The CNN-LSTM model increased the accuracy of the system by 3.55%, precision by 3.50%, recall by 4.46%, and F1-score by 3.30%. Overall, this study summarizes the existing problems of green rooftop buildings in Shanghai at this stage, which is conducive to formulating optimization strategies to improve the ecological benefits of green roof buildings and has important practical significance for realizing the sustainable development of human society.