Urban Climate Prediction And Adaptive Planning Strategies Based On WRF In The Future(2050s)

Global warming is one of the most urgent environmental crises at present,and its superposition with urbanization will exacerbate the urban heat island effect,which will lead to the emergence of extreme high temperature weather,which will seriously affect the livable environment of cities and the health and safety of residents.In order to better alleviate the impact of climate warming and urban heat island effect on the lives of urban residents,and avoid the occurrence of high temperature heat waves,it is necessary to use scientific methods to study the urban heat island effect under the background of global warming,and propose adaptive planning strategies.This article uses CMIP5(Coupled Model Intercomparison Project phase 5)global climate model and mesoscale weather model WRF(Weather Research And Forecasting)to couple,aiming at the future city of Dalian in the context of RCP8.5(Representative Concentration Pathways)Climate research and provide high-resolution climate change prediction data to predict potential changes in urban heat islands in the context of climate change.The study uses WRF to conduct two sets of numerical simulation studies,one is the initial boundary conditions corresponding to the current climate,and the other is the initial boundary conditions corresponding to the future climate.Under current climatic conditions,use GIS(Geographic Information System)to convert the current land use data of Dalian City into a WRF static geographic field,driven by NCEP(National Centers for Environmental Prediction)FNL(Final)weather data The WRF model uses 2005 as the representative year of the current climate and August as a typical month for hourly simulation;the WRF simulation results are verified by meteorological observation data from 5 international meteorological exchange stations,and the Pearson correlation coefficient R between the simulated data and the measured data The value is between 0.8-0.9,and the result shows the accuracy of the WRF model;under future climate conditions,the land use data will remain unchanged,and the WRF model will be driven by the meteorological data of the representative concentration path of RCP8.5,taking the year 2041-2050 as the future The climate represents the year,and August is a typical month for hourly simulation.The results show that under the RCP8.5 scenario,the average temperature of 2m above the ground in Dalian in 2050 will be 27.8℃;compared with the average temperature in August 2005,the average temperature will increase by 3.8℃,and the average temperature of 2m above the ground in August 2044 and 2048 will be 29.2℃,Compared to August 2005,the average temperature will increase by 5.2 ℃.The number of days of high temperature and heat wave in Dalian in August 2041-2050 reached 81 days.The average temperature during the high-temperature heat wave is obtained by superimposing the number of days of high-temperature heat waves to obtain the average temperature during the high-temperature heat wave,which is superimposed with the land use data of Dalian City to obtain the spatial distribution map of Dalian City’s exposure to assess the risk of future high-temperature heat waves in Dalian.The high-risk areas are mainly concentrated in the core area,Jinzhou City and Yingcheng sub-regions,the medium-risk areas are concentrated in Lushun City,Jinzhou City,the western and northern coastal areas,and the low-risk areas are concentrated in Dahei Mountain,the western suburbs of the mountains,and the north.Mountains and so on.Finally,from the aspects of urban planning,urban design and urban management,adaptive planning strategies are proposed for high-risk areas of heat wave disasters.Urban planning includes urban climate zoning,urban "cold island" protection,construction of urban ventilation corridors,and high-temperature disaster shelter planning.Urban design includes street layout design,widening streets and adjusting street orientation to facilitate ventilation,adding green belts and isolation belts to alleviate high temperature phenomena;controlling building height,building density,building form and building group layout combination in coastal areas to maximize the effect of urban ventilation;Improve the regional thermal environment and enhance the thermal comfort of the local environment by adjusting the material of the underlying surface,adding shading facilities,cooling spray facilities and three-dimensional greening.At the urban management level,the impact of high temperature and heat wave disasters on the health of cities and residents is reduced by establishing a high temperature and heat wave early warning system,formulating relevant policies and regulations,strengthening public propaganda,improving the medical system,and a protection system for vulnerable groups.