Evaluation And Prediction Of Microclimate And Thermal Comfort In Jinshan Lake Park In Huizhou City

With the acceleration of urbanization in China,the urban heat island effect is becoming more and more serious.Faced with the gradual deterioration of urban thermal environment,people begin to pay attention to the quality of living environment and thermal comfort.As a space carrier for people to return to nature,urban waterfront park is closely related to the daily living environment of residents,and people tend to avoid hot and uncomfortable space in their activities.Improving the thermal environment level of the waterfront park to meet the thermal comfort requirements of users can improve the utilization rate of the internal space of the park.The structure of trees and natural growth communities in the park green space has dynamic ecological benefits,and the microclimate environment affected by them also changes accordingly.This paper takes huizhou Jin Shanhu park as an example,through the CFD simulation software PHOENICS for the forecast of its status quo of environment and five years respectively simulated research environment,according to the simulation results,pedestrian height within the park inside air temperature,relative humidity,wind speed,and the human body thermal comfort evaluation index UTCI were analyzed,discusses the natural plant community growth of internal environment play a role in the park and its influence,and accordingly puts forward the optimization strategy of waterfront green space micro climate effect,the results show that:1.The present situation of simulation and forecast simulation under the high temperature problems existing in the park area are mostly focused on the park site above the rigid pavement,internal and external wind and cold source produces internal air convection park area,near the building wall,presents the state of "high temperature and low humidity,these areas are influenced by solar radiation and heat dissipation difficulties,form a" strong heat stress "and" in strong heat stress "area.Under these evaluation intervals,pedestrians on the site will feel obviously uncomfortable and thus affect their travel.2.As far as urban waterfront parks are concerned,water has a certain effect of cooling and humidifying inside the park site,but in hot and humid areas,such effect is not obvious when the outside air temperature is high and humidity is high.When the surrounding air flow is stable,vegetation has more obvious effect on environmental cooling and humidification,and it is easier to form "light heat stress" region.In the area with dense vegetation and low air velocity,the effect of cooling and humidifying reached 5.17℃ respectively.19.04%.At the same time,the wind speed has a certain strengthening effect between the canopy and the grass layer.The vegetation in the site had a significant effect on the UTCI value of the surrounding environment,but the external wind would weaken this effect.3.Under the influence of the natural growth of plant communities,48.85% of the sites with strong thermal stress changed to lower thermal stress in the predicted environment,and26.46% of the sites were affected by strong thermal stress(strong thermal stress;Severe problem areas were relieved by the predictive simulation,and some areas were completely relieved by heat stress.This is because the canopy width of plants will enhance their shielding effect against solar radiation as they grow,thus affecting the temperature and humidity above the site and improving the thermal comfort.Due to the increase of VEGETATION lai and canopy height,the vegetation layer has greater transpiration and waterrelease capacity,thus affecting the surrounding temperature and improving the environmental thermal comfort.With the enhancement of plant cold source effect,the effect of cold source wind within the site is enhanced,and the influence range is larger.The southeast wind,which has a negative effect on the outside,has a stronger barrier ability,so that the cold source effect of vegetation can act more on the inside of the site and improve the thermal comfort of the site.Through simulating the current situation and predicting the environment,the change of thermal environment in the site can be intuitively predicted,and corresponding transformation strategies can be given to areas that cannot be solved by only relying on plant community growth.By adding shade facilities such as green plants,umbrella pavilions and parasols,the shade space can be increased and the locally overheated microclimate environment can be adjusted.Or plant a few small trees near the convective region of external airflow and cold source airflow to reduce the possibility of convection occurring inside the site and give full play to the cold source effect of plant community.In addition,while improving the thermal environment of the park,the optimization cost is reduced and the site reconstruction benefit is improved.