Overview of modelling techniques for greenhouse microclimate environment and evapotranspiration

Domestication of plants by man through greenhouse crop production has revolutionized agricultural farming systems worldwide.Selecting the appropriate greenhouse technology together with the user-friendly evapotranspiration(ETc)model can optimize crop water use.The greenhouse microclimate environment has nearly zero wind speed and low radiation,hence low transpiration due to high temperature and humidity.Therefore,matching the greenhouse microclimate with the appropriate ETc model will certainly optimize crop water use efficiency since water is becoming a scarce resource globally,more so in the greenhouse environment.This is one of the main reasons why the gap between the dissemination of various advanced ETc models and the application by the greenhouse crop producers’community needs to be bridged.The likelihood or chances of rapidly disseminating and adopting advances in ETc estimating technology by a larger greenhouse crop producers community will increase if greenhouse ETc models become more user-friendly and available.The contribution of the greenhouse system to increased and sustainable food production must come through improved disseminating,adopting and use of existing greenhouse ETc models.FAO recommends a standard approach for the determination of crop water requirements utilizing the product of reference evapotranspiration(ET0)and crop coefficient(Kc)values.The FAO approach can also be used in greenhouse cultivation systems.However,studies connecting greenhouse technologies and methodologies for measuring ET0 or ETc in greenhouses are not available.There are also few studies undertaken that compared the performance of ET0 or ETc models under different categories of greenhouse conditions.In this review,a link between greenhouse technology and ET0 model or ETc model,and how existing knowledge and methodologies in ET0 or ETc measurements can actually enhance the sustainability of greenhouse farming have been highlighted.The categories of greenhouses,equipment commonly used,and the data collected for ET0 and ETc measurements have been established in the article.This review aimed to evaluate and summarize ET0 and ETc models currently available and being used in the various greenhouse categories.The accuracy assessment levels of the ET0 models about the category of the greenhouse microclimate environment were carried out.

Thermal Comfort Measurement and Landscape Reconstruction Strategy of Street Space Based on Decomposition Grid Method:A Case Study of Yangmeizhu Street

As an important public space in the city,street space is the second residence of people.Taking Yangmeizhu Street as the research object,this study established a street microclimate model in Beijing through microclimate measurement and simulation,and then calculated thermal comfort index of the street and evaluated thermal comfort of the street space and distribution model.The evaluation method used grid method to decompose and study and made several 10m×10m grids for inner space of the street,so as to compare deeply difference of microclimate environment in the street and analyze quantitatively relevance between street space elements(street pavement,street greening,building shadow coverage)and thermal comfort(physiological equivalent temperature PET)in the data.Finally,adaptive strategy of microclimate on street level was put forward to improve the environmental quality of public space in the old city by means of landscape design,aiming at creating a resilient and humanized street space and improving adaptability of microclimate and thermal comfort for living.