In plant factories,the plant microclimate is affected by the control system,plant physiological activities and aerodynamic characteristics of leaves,which often leads to poor ventilation uniformity,suboptimal environm...In plant factories,the plant microclimate is affected by the control system,plant physiological activities and aerodynamic characteristics of leaves,which often leads to poor ventilation uniformity,suboptimal environmental conditions and inefficient air conditioning.In this study,interlayer cool airflow(ILCA)was used to introduce room air into plants’internal canopy through vent holes in cultivation boards and air layer between cultivation boards and nutrient solution surface(interlayer).By using optimal operating parameters at a room temperature of 28℃,the ILCA system achieved similar cooling effects in the absence of a conventional air conditioning system and achieved an energy saving of 50.8% while bringing about positive microclimate change in the interlayer and nutrient solution.This resulted in significantly reduced root growth by 41.7% without a negative influence on lettuce crop yield.Future development in this precise microclimate control method is predicted to replace the conventional cooling(air conditioning)systems for crop production in plant factories.展开更多
Improvement of microclimate comfort is good to save energy,and create and improve communication space,and promote sustainable development of countryside.Wind is an important factor that influences outdoor microclimate...Improvement of microclimate comfort is good to save energy,and create and improve communication space,and promote sustainable development of countryside.Wind is an important factor that influences outdoor microclimate and plant is an economic,high-efficiency and healthy choice to improve wind environment.This article discussed technical strategies of improving the microclimate comfort of rural residence in southwest mountainous areas,by taking use of native vegetations.The strategy is to set up the wind-guide or wind-break plant landscape system through site planting,courtyard planting and residence planting.展开更多
This paper proposed through systematic analysis that road tail gas is an important source of PM2.5,and elaborated the infl uence of urban road space forms and road landscapes on urban microclimate,on the basis of whic...This paper proposed through systematic analysis that road tail gas is an important source of PM2.5,and elaborated the infl uence of urban road space forms and road landscapes on urban microclimate,on the basis of which gave corresponding landscape design suggestions for PM2.5 control.展开更多
The aim of this work is to study and quantify the air mass flow exchanged between inside and outside of the greenhouse, in order to determine the ventilation openings layout and the design effect on greenhouse airflow...The aim of this work is to study and quantify the air mass flow exchanged between inside and outside of the greenhouse, in order to determine the ventilation openings layout and the design effect on greenhouse airflow and microclimate distribution. The study was conducted over a 945 m2 multi-chapels arched greenhouse with a polyethylene cover and has thirteen crop rows oriented from north to south;the greenhouse was equipped with side wall and roof vents openings. A simulation was performed using different arrangements and configurations of ventilation openings with the same wind direction. Numerical simulation has been adopted in three dimensions (CFD), using the Fluent computer code which relies on the resolution of the Navier-Stokes equations. These equations were solved in the presence of the turbulence model (k - ε) and the Boussinesq model equation adopted to incorporate buoyancy forces. The effects of solar and atmospheric radiation were included by solving the radiative transfer equation (RTE), using Discrete Ordinate (DO) model. The effects of the roof openings, the presence of anti-insect screens and crops orientation were investigated and quantified. In a 3-span greenhouse with an anti-aphid in-sect screen in the vent openings, combining roof and sidewall vents gave a ventilation rate per unit opening area that was 1.4 times more than with only side vents. In the latter case, the difference of temperature between the inside and the outside of the greenhouse was greater than 3°C. Numerical simulations with an anti-insect screen having a porosity of 56% showed that the air exchange rate with combined ventilation was reduced by 48%. Finally, the paper focused on the effect of vent arrangement on the efficiency of the ventilation and the distribution of the microclimate inside the greenhouse. Results showed that computed ventilation rates varied from 53.43 to 70.95 kg/s, whereas temperature differences varied from 7.15°C to 10.14°C. This study also showed that other characteristics such as climate heterogeneity must be investigated in order to define the best ventilation configuration.展开更多
Tomato (Lycopersicon esculentum) is one of the important vegetables in supplying vitamins, minerals and fiber to human diets worldwide. Its successful production in the tropics is, however, constrained by environmenta...Tomato (Lycopersicon esculentum) is one of the important vegetables in supplying vitamins, minerals and fiber to human diets worldwide. Its successful production in the tropics is, however, constrained by environmental variations especially under open field conditions. Two trials were conducted at the Horticulture Research and Teaching Field, Egerton University, Kenya to evaluate the effects of agricultural nets (agronets) herein called eco-friendly nets (EFNs) and floating row covers (FRCs) on microclimate modification, yield, and quality of tomato. A randomized complete block design with five replications was used. Tomato plants were grown under fine mesh EFN (0.4-mm pore diameter) cover, large mesh EFN (0.9-mm pore diameter) cover or FRC. The EFN and FRC were maintained either permanently closed or opened thrice a week from 9 am to 3 pm. Two open control treatments were used: unsprayed (untreated control) or sprayed with chemicals (treated control). The use of EFN or FRC modified the microclimate with higher temperatures, lower diurnal temperature ranges, and higher volumetric water content recorded compared with the controls. On the other hand, light quantity and photosynthetic active radiation were reduced by the use of EFN and FRC compared with the controls. The use of FRC and EFN resulted in more fruit and higher percent in marketable yield compared with open field production. Fruit quality at harvest was also significantly improved by the use of EFN and FRC. Fruits with higher total soluble solids (TSS), lower titratable acidity (TA), and higher sugar acid ratio were obtained in EFN and FRC treatments compared with the controls. Fruits harvested from EFN and FRC were also firmer compared with control fruits. These findings demonstrate the potential of EFN and FRC in modifying microclimate conditions and improving yields and quality of tomato under tropical field conditions.展开更多
Numerous amphibian species occupy microhabitats with buffered thermal and moisture conditions,typically under forest canopies.Here,we assessed whether the insular endemic Salamandra corsica also uses this type of habi...Numerous amphibian species occupy microhabitats with buffered thermal and moisture conditions,typically under forest canopies.Here,we assessed whether the insular endemic Salamandra corsica also uses this type of habitat,which could have important implications for its conservation.We used data loggers to record the air temperature and air humidity at 4 h intervals over a period of 2 years,at 13 stations with a confirmed presence of S.corsica.These data were compared with those recorded at Corsican weather stations and those generated by a climate model(WorldClim 2).The weather station data showed significant deviations from the probe data,by an average of-1.26℃(minimum temperature),+2.61℃(maximum temperature),and-0.04%(relative humidity).Similarly,the WorldClim 2 data showed significant deviations from the probe data,by an average of-2.49°C(minimum temperature)and+1.69℃(maximum temperature).These discrepancies refl ect the use of densely vegetated and topographically complex habitats by S.corsica,which reduce temperature fluctuations.Overall,our results highlight the importance of natural vegetal cover in the conservation of populations of this endemic salamander.展开更多
After ground-mulching in plastic house.it is shown that it may display obvious effect on soil temperature.increase,but almost no effect on the internal air temperature,and light conditions can be improved,but the side...After ground-mulching in plastic house.it is shown that it may display obvious effect on soil temperature.increase,but almost no effect on the internal air temperature,and light conditions can be improved,but the side effects were presented on the relative humidity and the concentration of carbon dioxide.展开更多
In this paper, three types of green spaces in Xijing Community in Shijingshan District of Beijing were selected for as the measuring points, the HOBO portable weather station was used to monitor the microclimate envir...In this paper, three types of green spaces in Xijing Community in Shijingshan District of Beijing were selected for as the measuring points, the HOBO portable weather station was used to monitor the microclimate environmental changes in the same period and summarize the data of microclimate factors. The effectiveness of the simulation was verified by comparing the measured data with the simulated data obtained through ENVI-met. And strategies for microclimate adaptive design in residential areas were proposed according to the microclimate environmental characteristics of several green spaces.展开更多
Caragana microphylla is one of the key species for vegetation restoration in Horqin Sandy Land. Adopting field investigation and outdoor experiments,the microclimate effect of artificial C. microphylla communities wit...Caragana microphylla is one of the key species for vegetation restoration in Horqin Sandy Land. Adopting field investigation and outdoor experiments,the microclimate effect of artificial C. microphylla communities with different restoration years were studied by observing wind velocity,air temperature,relative humidity and soil temperature. The results show that:( 1) Caragana microphylla community has an obvious wind-breaking effect near ground surface. Compared with shifting dunes,the wind velocity in the 6-year-old and 11-year-old C. microphylla shrubs at the height of 30 cm separately decreases by 71. 9% and 76. 0%.( 2) Mean daily temperature in the 6-year-old and 11-yearold C. microphylla communities is 3. 7 ℃ and 4. 9 ℃ lower than in shifting dunes,respectively.( 3) The relative humidity of air in the Caragana microphylla shrubs is higher than in shifting dunes.( 4) Soil temperature in C. microphylla plantation is lower than in shifting dunes. These results are significant in further exploring material and energy exchange near surface layer of artificial vegetation in the extremely arid condition.展开更多
The Argentinian Yungas ecosystem, the more extensive of the two richest biodiversity ecoregions of the country, is subject to rapid deforestation and fragmentation. Because these fragments are the future biodiversity ...The Argentinian Yungas ecosystem, the more extensive of the two richest biodiversity ecoregions of the country, is subject to rapid deforestation and fragmentation. Because these fragments are the future biodiversity reserves of this ecosystem, it was interesting to know if they constitute small-scale replicas of the forest from which they were detached. Our objective was to characterise the fragments and compare them with sectors of continuous forest by studying the aboveground tree biomass (for the five most representative forest species), microclimate (three variables) and edaphic factors (three) as a function of distance from forest edge at 15, 25, 50, 100 and 200 meters. We selected two size categories for fragments: 5 - 10 ha and 100 - 150 ha, located in the lower Yungas forest (LYF). We did sampling during the dry and wet seasons. As a result, in the larger fragments, the distance exerts a significant effect on the records of the microclimate and edaphic variables, gradually modifying them from the edge to the interior (up to at least 100 meters). The variations are more evident in the wet season. Solar radiation and relative humidity were two of the factors with greater response (Spearman r= -0.89;p p ·ha-1, for small and big fragments, respectively). The five species studied show less density and trees of reduced dimensions (lower dbh and height). Fast-growing pioneer plant species and disturbance-loving lianas accompany them. Edge plant composition presents notorious changes in the bigger fragments. Biomass and ecosystem processes such as carbon cycling, which have been modified into fragments, both are directly associated with the structure and functioning in LYF remnants. The human and animal intervention detected in the area could be interacting synergistically with the microclimate and biological changes observed and potentiate the effects of degradation in the fragments, creating conditions of greater threat to LYF’s biodiversity. However, the management of the LYF ecosystem within an adequate land use scheme could conserve and even encourage the recovery of the fragments ensuring a natural legacy of great importance for the country. Financing opportunities and globally assumed responsibilities in the context of climate change could constitute a favorable framework for the implementation of strategies to safeguard these forests.展开更多
Microclimate is a climatic phenomenon of a very local area that is affected by the variation of natural earth surfaces in urban area. The urban growth expedites to change land use and land cover pattern of a city that...Microclimate is a climatic phenomenon of a very local area that is affected by the variation of natural earth surfaces in urban area. The urban growth expedites to change land use and land cover pattern of a city that modify the built environment, alter the composition of the atmosphere and form a distinct local climate in the cities. The radical land use and land cover change also alters the meteorological condition of a city. The relationship between land use land cover and thermal environment has long been studied to identify the impacts of urban growth but for this study area no such effort is taken. This study focuses on detecting the changing pattern of the cities adjacent Padma River and land uses, finally the impacts of such changes on the microclimate are assessed. This study is conducted based on Landsat time series data of 1989, 1996, 2005 and 2015 using ENVI and ArcGIS 10.2 softwares. The result demonstrates that the city is experiencing continuous change in land cover pattern, where the city centre is more vulnerable to change than its fringe. Another significant change is observed in the morphology of river Padma;it shows continuous shift of the river channel and increase in the Char land. The interactions of land use land cover and LST depicts a continuous increase in the mean surface temperature over bare soil following impervious area. The results underscore that two factors are contributing to influence the microclimate of the study area: First, the areal extent of surface water particularly the river Padma is losing stream and generating more bare soil (Char Land);second, impervious area is increasing and natural earth surfaces are decreasing.展开更多
With the continuous advancement of urbanization,how to improve the microclimate of urban public space and enhance ecological sustainability has become an important research direction of landscape architecture in the f...With the continuous advancement of urbanization,how to improve the microclimate of urban public space and enhance ecological sustainability has become an important research direction of landscape architecture in the future.Based on Envi-met,taking Min’an Community of Beijing City as research object,three-dimensional space model is established according to its architectural pattern,nature of underlying surface and green space pattern,and the change law of microclimate in the research zone under the existing spatial pattern and the influence mechanism of various factors are analyzed.PMV is taken as evaluation index of thermal comfort,and corresponding improvement measures are proposed,and improvement effect is simulated and improved.展开更多
Taking CNKI database as the data source and measuring visual map analysis tool Citespace as auxiliary tool,domestic 843 articles in recent 15 years are analyzed,and visualization maps such as time line analysis,instit...Taking CNKI database as the data source and measuring visual map analysis tool Citespace as auxiliary tool,domestic 843 articles in recent 15 years are analyzed,and visualization maps such as time line analysis,institutional cooperation network analysis,author collaboration network analysis,keyword co-occurrence,and emergent words analysis are drawn.Combined with the literature content analysis,four hot spots in the research field of landscape architecture microclimate in China are obtained,namely ENVI-MET,comfort,design strategy and urban green space.The research trend is thermal comfort,human body comfort and winter city.The research results can provide reference for the research on domestic garden microclimate.展开更多
As the basic unit of a city,community is an important carrier of residents’ healthy life.With the development of society,the environmental status of old communities has been unable to meet the needs of residents’ he...As the basic unit of a city,community is an important carrier of residents’ healthy life.With the development of society,the environmental status of old communities has been unable to meet the needs of residents’ healthy life,and it is urgent to optimize the community environment.The emergence of novel coronavirus also put forward more strict requirements for the grassroots governance of old communities in China.Taking Fuguoli community in Beijing City as an example,the problems existing in the external environment of old communities were excavated from the perspective of functional requirements,and the distributed green space layout pattern and the dynamic simulation of community microclimate environment was constructed through the method of field survey and numerical simulation.Furthermore,the environmental optimization strategies of old communities with combination of peacetime and epidemic situation were put forward to help the epidemic prevention and control.展开更多
Intensified human population encourages urbanization changing the morphology and metabolism of urban environments, thus altering the local climate and outdoor thermal comfort (OTC) in public spaces. OTC is an increasi...Intensified human population encourages urbanization changing the morphology and metabolism of urban environments, thus altering the local climate and outdoor thermal comfort (OTC) in public spaces. OTC is an increasingly urgent area of research for tropical climates. This study explores the literature from the Scopus database on urban microclimate and OTC in public spaces and contrasts the studies in warm-humid cities through a bibliometric mapping of literature. The adapted methodology includes;Bibliometric Search, Scientometric Analysis, and Content analysis using VOSviewer software to identify the evolution paths, gaps, and the most recent movement of OTC assessments in urban public spaces. Results reveal five evolution paths related to all climatic regions;1) materials and cooling strategies, 2) simulation modeling and urban planning, 3) design parameters affecting thermal perception, 4) cooling effects of green infrastructure, and 5) thermal adaptation in urban design. Although urban morphology and vegetation have been received the highest attention respectively, only a few for blue infrastructure related to warm-humid cities. This review identified five research gaps;the impact of blue infrastructure on OTC, strategies to overcome the effect of reflective materials, vegetation configurations in street canyons with wind flow, OTC improvements in asymmetrical street canyons, and how local climate zone (LCZ) classification approach could be used for OTC assessments. Past empirical studies have revealed that urban vegetation, surface materials, and morphological parameters are of paramount importance. Yet, the urban blue infrastructure has not received adequate research. Recently, the attention of researchers has been drawn to strategies in improving OTC using micro-meteorological simulation modelling to examine the impact of urban design interventions. Finally, comprehensive content analysis, bibliographic coupling based on documents, co-occurrence of all-keywords, are suggested for future bibliometric reviews. Finally, further research on recommended areas would assist decision-makers in planning and design to enhance livability by improving microclimate and OTC in urban spaces.展开更多
Based on the air temperature (1.0 m and 1.5 m) every 10 minutes, ground temperature (0 cm, 10 cm and 20 cm) and air relative humidity (1.5 m) from the stations in the greenhouse, and the air temperature (1.5 m) every ...Based on the air temperature (1.0 m and 1.5 m) every 10 minutes, ground temperature (0 cm, 10 cm and 20 cm) and air relative humidity (1.5 m) from the stations in the greenhouse, and the air temperature (1.5 m) every 10 minutes and air relative humidity (1.5 m) from the regional stations in Chutouling Town, Jizhou district of Tianjin from April 2019 to November 2020, the changes of the microclimate in the greenhouse of Pleurotus nebrodensis were studied. The results explained that 1) the heat preservation effect of the greenhouse was the best in spring, the effective accumulative temperature and active accumulated temperature in the greenhouse had increased by 203.7°C and 233.7°C, respectively, compared with that outside the greenhouse. In the sunny or cloudy days of summer, the range of temperature difference (TD) between inside and outside the greenhouse was wider, more than 90% of the TD ranged from -6.0°C to 2.9°C;2) the minimum temperature occurred later because of heat preservation effect of the greenhouse, the delay time can reach about 30 minutes in spring, it was about 20 minutes in summer and autumn, and 10 minutes in winter, however, the maximum temperature appeared earlier, it occurred 50 minutes ahead of time in spring, and it has been advanced by 20 minutes in summer and 10 minutes in autumn and winter;3) the greenhouse mainly played a role of increasing humidity, the humidity in the greenhouse basically was larger than that outside the greenhouse, except the periods of 03:10-07:20 in spring, 0:00-08:50 and 23:10-23:50 in winter;4) the temperature in the greenhouse significantly positively correlated with the temperature outside the greenhouse, the stronger correlation also appeared between the ground temperature (at the depth of 0 cm and 10 cm) in the greenhouse and the temperature inside and outside the greenhouse, however, there was a weak correlation between the ground temperature (20 cm) and the temperature inside and outside the greenhouse, this implies that the change of temperature had less impact on the ground temperature at deeper soil layers. This paper is of significance in identifying the microclimate in the Pleurotus nebrodensis greenhouse.展开更多
A demand for renewable alternatives that would be able to deal with the problems related to well-being is directly linked to the world’s growing needs to save energy and reduce environmental costs. For a project impl...A demand for renewable alternatives that would be able to deal with the problems related to well-being is directly linked to the world’s growing needs to save energy and reduce environmental costs. For a project implementation addressing these issues, it is essential to know the climatic conditions of the target area. Taking natural ventilation, climatic factors, and renewable alternatives as important sources of comfort, in this work, passive strategies, through the utilization of microclimate elements as well as the location of outside obstacles, were imposed on an initial and specific project. The objective was to introduce obstacles which could interfere in the field of external wind and evaluate whether this outside intervention is able to make changes in indoor air circulation. The wind fields for the studied cases were obtained by computational simulations, and their consequences were analyzed to attain thermal comfort. The method adopted to obtain the wind fields was a Petrov-Galerkin type method, which is a stabilized mixed finite element method of the Navier-Stokes equations considering the incompressibility and formulated in primitive variables, velocity and pressure. The obtained results point to the solutions that promote the increase or decrease of the wind-field intensity.展开更多
Background:Increasing urbanization as well as global warming requires an investigation of the infuence of diferent construction methods and ground surfaces on the urban heat island efect(UHI efect).The extent of the i...Background:Increasing urbanization as well as global warming requires an investigation of the infuence of diferent construction methods and ground surfaces on the urban heat island efect(UHI efect).The extent of the infuence of the urban structure,the building materials used and their surfaces on the UHI efect can be signifcantly reduced already in the planning phase using a designated OpenFOAM-based solver“uhiSolver”.Results:In the frst part of this research work,it is shown that inner building details and components can be neglected while still obtaining sufciently accurate results.For this purpose,the building model was divided into two layers:a surface layer without mass,where the interaction with radiation takes place,and a component layer,which contains all relevant components and cavities of the building represented with mass-averaged material properties.It has become apparent that the three parameters—albedo,heat capacity and thermal resistance—which have a decisive infuence on the interaction,have diferent efects on the component temperatures and the surface temperatures.In the second part of this research work,dynamic 3D computational fuid dynamics(CFD)simulations are performed with uhiSolver for a residential block in Vienna.Comparing the simulation results with measurement data collected on site,it is shown that the simplifed assumption of homogeneous material data for building bodies provides very good results for the validation case investigated.However,the infuence of the greening measures in the courtyard of the residential block on the air temperature is found to be negligible.Furthermore,it was observed that due to locally higher radiation density,lower air velocities and higher air humidity,the apparent temperature in the courtyard is sometimes perceived to be higher than in the adjacent streets,despite the lower air temperature.Conclusions:Simplifying the modeling process of the uhiSolver software by reducing the model complexity helps to reduce manual work for setting up appropriate boundary conditions of buildings.Compared to market competitors,good results are obtained for the validation case Kandlgasse presented in this research work,despite the simplifcations proposed.Thus,uhiSolver can be used as a robust analytical tool for urban planning.展开更多
Environmental parameter measurements from various sensors spatially distributed in greenhouse crops can be used to create an accurate and detailed depiction of the climate in different regions of the greenhouse.Microc...Environmental parameter measurements from various sensors spatially distributed in greenhouse crops can be used to create an accurate and detailed depiction of the climate in different regions of the greenhouse.Microclimate environments have an impact on crop yield,productivity,quantitative and qualitative characteristics of plants,and various plant diseases.In this study,an automatic monitoring system based on a wireless sensor network was designed to monitor the survival rate of greenhouse crops.The system design includes a sensor model selection and placement process,host computer monitoring software and communication module design.The Zigbee protocol was used for wireless communication between the nodes.The proposed fuzzy-PID controller was easy to design and highly adaptive to the measurement errors of the sensors.The test results show that the system valuable for monitoring the environment in the greenhouse,where it was successful in controlling and maintaining an optimal microclimate condition.展开更多
Aims We studied the influence of tree species diversity on the dynamics of coarse wood decomposition in developing forest communities in a natural,topographically heterogeneous landscape.Using the litter bag technique...Aims We studied the influence of tree species diversity on the dynamics of coarse wood decomposition in developing forest communities in a natural,topographically heterogeneous landscape.Using the litter bag technique,we investigated how and to which extent canopy tree species richness or the exclusion of mesoinvertebrates and macroinvertebrates affected wood decomposition in the light of natural variations in the microclimate.We compared the relative importance of the two aspects(experimental treatment versus microclimate)on wood decay rates using Schima superba as a standard litter.Methods Coarse woody debris(CWD)was deposited in litter bags with two different mesh sizes in a total of 134 plots along a gradient of canopy tree species richness(0-24 species).Wood decomposition was assessed at two consecutive time points,one and three years after deposition in the field.Local climatic conditions were assessed throughout the duration of the experiment.Microclimatic conditions were assessed both,directly in the field as well as indirectly via correlations with local topography.We used analysis of variance based approaches to assess the relative importance of the treatments(community tree species richness and macro invertebrate exclusion)and microclimatic conditions on wood decay.Important Findings No direct influence of tree species richness on wood decay could be detected.However,the exclusion of macroinvertebrates significantly decreased wood decomposition rates.In addition,microclimatic conditions accounted for a substantial proportion of explained variance in the observed data.Here,wood decomposition was negatively affected by low mean temperatures and high variations in local humidity and temperature.However,tree species richness as well as the respective species composition affected the presence of termites within forest communities.These,in turn,significantly increased the decay of CWD.The strength of both,experimental treatment and microclimate increased with ongoing decomposition.We conclude that,while tree species richness per se has no direct influence on wood decomposition,its influence on the local arthropod decomposer community(especially the presence of termites)does have an effect.展开更多
基金This work was supported by the National Natural Science Foundation of China(31701969)the Key Projects of Ningxia Key R&D Program Fund,China(2018BBF02012)the Science and Technology Program of Shaanxi Province,China(2017ZDXM-NY-057).
文摘In plant factories,the plant microclimate is affected by the control system,plant physiological activities and aerodynamic characteristics of leaves,which often leads to poor ventilation uniformity,suboptimal environmental conditions and inefficient air conditioning.In this study,interlayer cool airflow(ILCA)was used to introduce room air into plants’internal canopy through vent holes in cultivation boards and air layer between cultivation boards and nutrient solution surface(interlayer).By using optimal operating parameters at a room temperature of 28℃,the ILCA system achieved similar cooling effects in the absence of a conventional air conditioning system and achieved an energy saving of 50.8% while bringing about positive microclimate change in the interlayer and nutrient solution.This resulted in significantly reduced root growth by 41.7% without a negative influence on lettuce crop yield.Future development in this precise microclimate control method is predicted to replace the conventional cooling(air conditioning)systems for crop production in plant factories.
基金Sponsored by Foundation or Science&lechnology Department of Sichuan Province(2008SZ0151)
文摘Improvement of microclimate comfort is good to save energy,and create and improve communication space,and promote sustainable development of countryside.Wind is an important factor that influences outdoor microclimate and plant is an economic,high-efficiency and healthy choice to improve wind environment.This article discussed technical strategies of improving the microclimate comfort of rural residence in southwest mountainous areas,by taking use of native vegetations.The strategy is to set up the wind-guide or wind-break plant landscape system through site planting,courtyard planting and residence planting.
文摘This paper proposed through systematic analysis that road tail gas is an important source of PM2.5,and elaborated the infl uence of urban road space forms and road landscapes on urban microclimate,on the basis of which gave corresponding landscape design suggestions for PM2.5 control.
文摘The aim of this work is to study and quantify the air mass flow exchanged between inside and outside of the greenhouse, in order to determine the ventilation openings layout and the design effect on greenhouse airflow and microclimate distribution. The study was conducted over a 945 m2 multi-chapels arched greenhouse with a polyethylene cover and has thirteen crop rows oriented from north to south;the greenhouse was equipped with side wall and roof vents openings. A simulation was performed using different arrangements and configurations of ventilation openings with the same wind direction. Numerical simulation has been adopted in three dimensions (CFD), using the Fluent computer code which relies on the resolution of the Navier-Stokes equations. These equations were solved in the presence of the turbulence model (k - ε) and the Boussinesq model equation adopted to incorporate buoyancy forces. The effects of solar and atmospheric radiation were included by solving the radiative transfer equation (RTE), using Discrete Ordinate (DO) model. The effects of the roof openings, the presence of anti-insect screens and crops orientation were investigated and quantified. In a 3-span greenhouse with an anti-aphid in-sect screen in the vent openings, combining roof and sidewall vents gave a ventilation rate per unit opening area that was 1.4 times more than with only side vents. In the latter case, the difference of temperature between the inside and the outside of the greenhouse was greater than 3°C. Numerical simulations with an anti-insect screen having a porosity of 56% showed that the air exchange rate with combined ventilation was reduced by 48%. Finally, the paper focused on the effect of vent arrangement on the efficiency of the ventilation and the distribution of the microclimate inside the greenhouse. Results showed that computed ventilation rates varied from 53.43 to 70.95 kg/s, whereas temperature differences varied from 7.15°C to 10.14°C. This study also showed that other characteristics such as climate heterogeneity must be investigated in order to define the best ventilation configuration.
文摘Tomato (Lycopersicon esculentum) is one of the important vegetables in supplying vitamins, minerals and fiber to human diets worldwide. Its successful production in the tropics is, however, constrained by environmental variations especially under open field conditions. Two trials were conducted at the Horticulture Research and Teaching Field, Egerton University, Kenya to evaluate the effects of agricultural nets (agronets) herein called eco-friendly nets (EFNs) and floating row covers (FRCs) on microclimate modification, yield, and quality of tomato. A randomized complete block design with five replications was used. Tomato plants were grown under fine mesh EFN (0.4-mm pore diameter) cover, large mesh EFN (0.9-mm pore diameter) cover or FRC. The EFN and FRC were maintained either permanently closed or opened thrice a week from 9 am to 3 pm. Two open control treatments were used: unsprayed (untreated control) or sprayed with chemicals (treated control). The use of EFN or FRC modified the microclimate with higher temperatures, lower diurnal temperature ranges, and higher volumetric water content recorded compared with the controls. On the other hand, light quantity and photosynthetic active radiation were reduced by the use of EFN and FRC compared with the controls. The use of FRC and EFN resulted in more fruit and higher percent in marketable yield compared with open field production. Fruit quality at harvest was also significantly improved by the use of EFN and FRC. Fruits with higher total soluble solids (TSS), lower titratable acidity (TA), and higher sugar acid ratio were obtained in EFN and FRC treatments compared with the controls. Fruits harvested from EFN and FRC were also firmer compared with control fruits. These findings demonstrate the potential of EFN and FRC in modifying microclimate conditions and improving yields and quality of tomato under tropical field conditions.
文摘Numerous amphibian species occupy microhabitats with buffered thermal and moisture conditions,typically under forest canopies.Here,we assessed whether the insular endemic Salamandra corsica also uses this type of habitat,which could have important implications for its conservation.We used data loggers to record the air temperature and air humidity at 4 h intervals over a period of 2 years,at 13 stations with a confirmed presence of S.corsica.These data were compared with those recorded at Corsican weather stations and those generated by a climate model(WorldClim 2).The weather station data showed significant deviations from the probe data,by an average of-1.26℃(minimum temperature),+2.61℃(maximum temperature),and-0.04%(relative humidity).Similarly,the WorldClim 2 data showed significant deviations from the probe data,by an average of-2.49°C(minimum temperature)and+1.69℃(maximum temperature).These discrepancies refl ect the use of densely vegetated and topographically complex habitats by S.corsica,which reduce temperature fluctuations.Overall,our results highlight the importance of natural vegetal cover in the conservation of populations of this endemic salamander.
文摘After ground-mulching in plastic house.it is shown that it may display obvious effect on soil temperature.increase,but almost no effect on the internal air temperature,and light conditions can be improved,but the side effects were presented on the relative humidity and the concentration of carbon dioxide.
基金Sponsored by 2018 Beijing Municipal University Academic Human Resources Development—Youth Talent Support Program(PXM2018_014212_000043)North China University of Technology “YuYOU” Talent Training Program
文摘In this paper, three types of green spaces in Xijing Community in Shijingshan District of Beijing were selected for as the measuring points, the HOBO portable weather station was used to monitor the microclimate environmental changes in the same period and summarize the data of microclimate factors. The effectiveness of the simulation was verified by comparing the measured data with the simulated data obtained through ENVI-met. And strategies for microclimate adaptive design in residential areas were proposed according to the microclimate environmental characteristics of several green spaces.
基金Supported by Project of National Natural Science Foundation(71203057,41271115,41071187)Young Scholar Project of Humanities and Social Science Foundation of Ministry of Education(11YJCZH056)Ph.D Foundation Project of Henan Polytechnic University(B2011-017)
文摘Caragana microphylla is one of the key species for vegetation restoration in Horqin Sandy Land. Adopting field investigation and outdoor experiments,the microclimate effect of artificial C. microphylla communities with different restoration years were studied by observing wind velocity,air temperature,relative humidity and soil temperature. The results show that:( 1) Caragana microphylla community has an obvious wind-breaking effect near ground surface. Compared with shifting dunes,the wind velocity in the 6-year-old and 11-year-old C. microphylla shrubs at the height of 30 cm separately decreases by 71. 9% and 76. 0%.( 2) Mean daily temperature in the 6-year-old and 11-yearold C. microphylla communities is 3. 7 ℃ and 4. 9 ℃ lower than in shifting dunes,respectively.( 3) The relative humidity of air in the Caragana microphylla shrubs is higher than in shifting dunes.( 4) Soil temperature in C. microphylla plantation is lower than in shifting dunes. These results are significant in further exploring material and energy exchange near surface layer of artificial vegetation in the extremely arid condition.
文摘The Argentinian Yungas ecosystem, the more extensive of the two richest biodiversity ecoregions of the country, is subject to rapid deforestation and fragmentation. Because these fragments are the future biodiversity reserves of this ecosystem, it was interesting to know if they constitute small-scale replicas of the forest from which they were detached. Our objective was to characterise the fragments and compare them with sectors of continuous forest by studying the aboveground tree biomass (for the five most representative forest species), microclimate (three variables) and edaphic factors (three) as a function of distance from forest edge at 15, 25, 50, 100 and 200 meters. We selected two size categories for fragments: 5 - 10 ha and 100 - 150 ha, located in the lower Yungas forest (LYF). We did sampling during the dry and wet seasons. As a result, in the larger fragments, the distance exerts a significant effect on the records of the microclimate and edaphic variables, gradually modifying them from the edge to the interior (up to at least 100 meters). The variations are more evident in the wet season. Solar radiation and relative humidity were two of the factors with greater response (Spearman r= -0.89;p p ·ha-1, for small and big fragments, respectively). The five species studied show less density and trees of reduced dimensions (lower dbh and height). Fast-growing pioneer plant species and disturbance-loving lianas accompany them. Edge plant composition presents notorious changes in the bigger fragments. Biomass and ecosystem processes such as carbon cycling, which have been modified into fragments, both are directly associated with the structure and functioning in LYF remnants. The human and animal intervention detected in the area could be interacting synergistically with the microclimate and biological changes observed and potentiate the effects of degradation in the fragments, creating conditions of greater threat to LYF’s biodiversity. However, the management of the LYF ecosystem within an adequate land use scheme could conserve and even encourage the recovery of the fragments ensuring a natural legacy of great importance for the country. Financing opportunities and globally assumed responsibilities in the context of climate change could constitute a favorable framework for the implementation of strategies to safeguard these forests.
文摘Microclimate is a climatic phenomenon of a very local area that is affected by the variation of natural earth surfaces in urban area. The urban growth expedites to change land use and land cover pattern of a city that modify the built environment, alter the composition of the atmosphere and form a distinct local climate in the cities. The radical land use and land cover change also alters the meteorological condition of a city. The relationship between land use land cover and thermal environment has long been studied to identify the impacts of urban growth but for this study area no such effort is taken. This study focuses on detecting the changing pattern of the cities adjacent Padma River and land uses, finally the impacts of such changes on the microclimate are assessed. This study is conducted based on Landsat time series data of 1989, 1996, 2005 and 2015 using ENVI and ArcGIS 10.2 softwares. The result demonstrates that the city is experiencing continuous change in land cover pattern, where the city centre is more vulnerable to change than its fringe. Another significant change is observed in the morphology of river Padma;it shows continuous shift of the river channel and increase in the Char land. The interactions of land use land cover and LST depicts a continuous increase in the mean surface temperature over bare soil following impervious area. The results underscore that two factors are contributing to influence the microclimate of the study area: First, the areal extent of surface water particularly the river Padma is losing stream and generating more bare soil (Char Land);second, impervious area is increasing and natural earth surfaces are decreasing.
基金Sponsored by National Natural Science Foundation of China(51708004)Yuyou Talent Training Program of North China University of Technology(215051360020XN160/009)+2 种基金Beijing Natural Science Foundation(8202017)Basal Research Fund of North China University of Technology(110052972027/154)2018 Beijing Municipal University Academic Human Resources Development—Youth Talent Support Program(PXM2018014212000043)。
文摘With the continuous advancement of urbanization,how to improve the microclimate of urban public space and enhance ecological sustainability has become an important research direction of landscape architecture in the future.Based on Envi-met,taking Min’an Community of Beijing City as research object,three-dimensional space model is established according to its architectural pattern,nature of underlying surface and green space pattern,and the change law of microclimate in the research zone under the existing spatial pattern and the influence mechanism of various factors are analyzed.PMV is taken as evaluation index of thermal comfort,and corresponding improvement measures are proposed,and improvement effect is simulated and improved.
基金Sponsored by the National Natural Science Foundation of China(Youth Program)(51908063)。
文摘Taking CNKI database as the data source and measuring visual map analysis tool Citespace as auxiliary tool,domestic 843 articles in recent 15 years are analyzed,and visualization maps such as time line analysis,institutional cooperation network analysis,author collaboration network analysis,keyword co-occurrence,and emergent words analysis are drawn.Combined with the literature content analysis,four hot spots in the research field of landscape architecture microclimate in China are obtained,namely ENVI-MET,comfort,design strategy and urban green space.The research trend is thermal comfort,human body comfort and winter city.The research results can provide reference for the research on domestic garden microclimate.
基金General Project of Natural Science Foundation of Beijing City (8202017)Youth Talent Support Program of 2018 Beijing Municipal University Academic Human Resources Development (PXM2018_014212_000043)。
文摘As the basic unit of a city,community is an important carrier of residents’ healthy life.With the development of society,the environmental status of old communities has been unable to meet the needs of residents’ healthy life,and it is urgent to optimize the community environment.The emergence of novel coronavirus also put forward more strict requirements for the grassroots governance of old communities in China.Taking Fuguoli community in Beijing City as an example,the problems existing in the external environment of old communities were excavated from the perspective of functional requirements,and the distributed green space layout pattern and the dynamic simulation of community microclimate environment was constructed through the method of field survey and numerical simulation.Furthermore,the environmental optimization strategies of old communities with combination of peacetime and epidemic situation were put forward to help the epidemic prevention and control.
文摘Intensified human population encourages urbanization changing the morphology and metabolism of urban environments, thus altering the local climate and outdoor thermal comfort (OTC) in public spaces. OTC is an increasingly urgent area of research for tropical climates. This study explores the literature from the Scopus database on urban microclimate and OTC in public spaces and contrasts the studies in warm-humid cities through a bibliometric mapping of literature. The adapted methodology includes;Bibliometric Search, Scientometric Analysis, and Content analysis using VOSviewer software to identify the evolution paths, gaps, and the most recent movement of OTC assessments in urban public spaces. Results reveal five evolution paths related to all climatic regions;1) materials and cooling strategies, 2) simulation modeling and urban planning, 3) design parameters affecting thermal perception, 4) cooling effects of green infrastructure, and 5) thermal adaptation in urban design. Although urban morphology and vegetation have been received the highest attention respectively, only a few for blue infrastructure related to warm-humid cities. This review identified five research gaps;the impact of blue infrastructure on OTC, strategies to overcome the effect of reflective materials, vegetation configurations in street canyons with wind flow, OTC improvements in asymmetrical street canyons, and how local climate zone (LCZ) classification approach could be used for OTC assessments. Past empirical studies have revealed that urban vegetation, surface materials, and morphological parameters are of paramount importance. Yet, the urban blue infrastructure has not received adequate research. Recently, the attention of researchers has been drawn to strategies in improving OTC using micro-meteorological simulation modelling to examine the impact of urban design interventions. Finally, comprehensive content analysis, bibliographic coupling based on documents, co-occurrence of all-keywords, are suggested for future bibliometric reviews. Finally, further research on recommended areas would assist decision-makers in planning and design to enhance livability by improving microclimate and OTC in urban spaces.
文摘Based on the air temperature (1.0 m and 1.5 m) every 10 minutes, ground temperature (0 cm, 10 cm and 20 cm) and air relative humidity (1.5 m) from the stations in the greenhouse, and the air temperature (1.5 m) every 10 minutes and air relative humidity (1.5 m) from the regional stations in Chutouling Town, Jizhou district of Tianjin from April 2019 to November 2020, the changes of the microclimate in the greenhouse of Pleurotus nebrodensis were studied. The results explained that 1) the heat preservation effect of the greenhouse was the best in spring, the effective accumulative temperature and active accumulated temperature in the greenhouse had increased by 203.7°C and 233.7°C, respectively, compared with that outside the greenhouse. In the sunny or cloudy days of summer, the range of temperature difference (TD) between inside and outside the greenhouse was wider, more than 90% of the TD ranged from -6.0°C to 2.9°C;2) the minimum temperature occurred later because of heat preservation effect of the greenhouse, the delay time can reach about 30 minutes in spring, it was about 20 minutes in summer and autumn, and 10 minutes in winter, however, the maximum temperature appeared earlier, it occurred 50 minutes ahead of time in spring, and it has been advanced by 20 minutes in summer and 10 minutes in autumn and winter;3) the greenhouse mainly played a role of increasing humidity, the humidity in the greenhouse basically was larger than that outside the greenhouse, except the periods of 03:10-07:20 in spring, 0:00-08:50 and 23:10-23:50 in winter;4) the temperature in the greenhouse significantly positively correlated with the temperature outside the greenhouse, the stronger correlation also appeared between the ground temperature (at the depth of 0 cm and 10 cm) in the greenhouse and the temperature inside and outside the greenhouse, however, there was a weak correlation between the ground temperature (20 cm) and the temperature inside and outside the greenhouse, this implies that the change of temperature had less impact on the ground temperature at deeper soil layers. This paper is of significance in identifying the microclimate in the Pleurotus nebrodensis greenhouse.
基金the FAPERJ(State of Rio de Janeiro research supporting foundation)
文摘A demand for renewable alternatives that would be able to deal with the problems related to well-being is directly linked to the world’s growing needs to save energy and reduce environmental costs. For a project implementation addressing these issues, it is essential to know the climatic conditions of the target area. Taking natural ventilation, climatic factors, and renewable alternatives as important sources of comfort, in this work, passive strategies, through the utilization of microclimate elements as well as the location of outside obstacles, were imposed on an initial and specific project. The objective was to introduce obstacles which could interfere in the field of external wind and evaluate whether this outside intervention is able to make changes in indoor air circulation. The wind fields for the studied cases were obtained by computational simulations, and their consequences were analyzed to attain thermal comfort. The method adopted to obtain the wind fields was a Petrov-Galerkin type method, which is a stabilized mixed finite element method of the Navier-Stokes equations considering the incompressibility and formulated in primitive variables, velocity and pressure. The obtained results point to the solutions that promote the increase or decrease of the wind-field intensity.
基金funded byÖsterreichische Forschungsförderungsgesellschaft FFG—feasibility study,Grant number 873045.
文摘Background:Increasing urbanization as well as global warming requires an investigation of the infuence of diferent construction methods and ground surfaces on the urban heat island efect(UHI efect).The extent of the infuence of the urban structure,the building materials used and their surfaces on the UHI efect can be signifcantly reduced already in the planning phase using a designated OpenFOAM-based solver“uhiSolver”.Results:In the frst part of this research work,it is shown that inner building details and components can be neglected while still obtaining sufciently accurate results.For this purpose,the building model was divided into two layers:a surface layer without mass,where the interaction with radiation takes place,and a component layer,which contains all relevant components and cavities of the building represented with mass-averaged material properties.It has become apparent that the three parameters—albedo,heat capacity and thermal resistance—which have a decisive infuence on the interaction,have diferent efects on the component temperatures and the surface temperatures.In the second part of this research work,dynamic 3D computational fuid dynamics(CFD)simulations are performed with uhiSolver for a residential block in Vienna.Comparing the simulation results with measurement data collected on site,it is shown that the simplifed assumption of homogeneous material data for building bodies provides very good results for the validation case investigated.However,the infuence of the greening measures in the courtyard of the residential block on the air temperature is found to be negligible.Furthermore,it was observed that due to locally higher radiation density,lower air velocities and higher air humidity,the apparent temperature in the courtyard is sometimes perceived to be higher than in the adjacent streets,despite the lower air temperature.Conclusions:Simplifying the modeling process of the uhiSolver software by reducing the model complexity helps to reduce manual work for setting up appropriate boundary conditions of buildings.Compared to market competitors,good results are obtained for the validation case Kandlgasse presented in this research work,despite the simplifcations proposed.Thus,uhiSolver can be used as a robust analytical tool for urban planning.
基金This work is financially supported by the National Natural Science Foundation of China(No.31901400)Zhejiang Province Natural Science Foundation(No.LQ20C130008)the Key Laboratory of Equipment and the Informatization in Environment Controlled Agriculture,Ministry of Agriculture and Rural Affairs(No.2011NYZD1802).
文摘Environmental parameter measurements from various sensors spatially distributed in greenhouse crops can be used to create an accurate and detailed depiction of the climate in different regions of the greenhouse.Microclimate environments have an impact on crop yield,productivity,quantitative and qualitative characteristics of plants,and various plant diseases.In this study,an automatic monitoring system based on a wireless sensor network was designed to monitor the survival rate of greenhouse crops.The system design includes a sensor model selection and placement process,host computer monitoring software and communication module design.The Zigbee protocol was used for wireless communication between the nodes.The proposed fuzzy-PID controller was easy to design and highly adaptive to the measurement errors of the sensors.The test results show that the system valuable for monitoring the environment in the greenhouse,where it was successful in controlling and maintaining an optimal microclimate condition.
基金the DFG for the financial support granted to the BEF-China research consortium(FOR 871).
文摘Aims We studied the influence of tree species diversity on the dynamics of coarse wood decomposition in developing forest communities in a natural,topographically heterogeneous landscape.Using the litter bag technique,we investigated how and to which extent canopy tree species richness or the exclusion of mesoinvertebrates and macroinvertebrates affected wood decomposition in the light of natural variations in the microclimate.We compared the relative importance of the two aspects(experimental treatment versus microclimate)on wood decay rates using Schima superba as a standard litter.Methods Coarse woody debris(CWD)was deposited in litter bags with two different mesh sizes in a total of 134 plots along a gradient of canopy tree species richness(0-24 species).Wood decomposition was assessed at two consecutive time points,one and three years after deposition in the field.Local climatic conditions were assessed throughout the duration of the experiment.Microclimatic conditions were assessed both,directly in the field as well as indirectly via correlations with local topography.We used analysis of variance based approaches to assess the relative importance of the treatments(community tree species richness and macro invertebrate exclusion)and microclimatic conditions on wood decay.Important Findings No direct influence of tree species richness on wood decay could be detected.However,the exclusion of macroinvertebrates significantly decreased wood decomposition rates.In addition,microclimatic conditions accounted for a substantial proportion of explained variance in the observed data.Here,wood decomposition was negatively affected by low mean temperatures and high variations in local humidity and temperature.However,tree species richness as well as the respective species composition affected the presence of termites within forest communities.These,in turn,significantly increased the decay of CWD.The strength of both,experimental treatment and microclimate increased with ongoing decomposition.We conclude that,while tree species richness per se has no direct influence on wood decomposition,its influence on the local arthropod decomposer community(especially the presence of termites)does have an effect.
