| The large amount of waste heat generated in human production and life has an important impact on the temperature in the urban environment,the structure of the urban boundary layer,air quality and human health.It is of great significance to carry out the estimation of anthropogenic heat emission inventory and the study of its impact on the urban thermal environment.However,the current calculation methods for the anthropogenic heat emission inventory have many disadvantages,such as a wide variety of basic data required,a complex calculation process,and large deviations in spatial distribution and emissions.This study uses statistical regression method to calculate the anthropogenic heat emission inventory in the Pearl River Delta region from 2007 to 2015 based on the CO and NOx pollution source inventory.The emission trends,changes in the types of heat emission sources and the evolution of spatial patterns are sorted out,and the former are evaluated using the anthropogenic heat inventory calculated by the source inventory method and the uncertainty analysis is performed using the Monte Carlo numerical method.Using WRF/UCM(a regional meteorological model coupled with an urban single-layer canopy model),the impact of changes in the input of anthropogenic heat emissions on the urban microclimate was evaluated,A high temperature heat wave event was simulated to explore the impact of anthropogenic heat emissions on the urban heat balance and the high temperature of the city.The results show that the annual average anthropogenic heat in the Pearl River Delta from 2007 to 2015 was greater than 9 W·m-2,and the peak anthropogenic heat emission appeared in 2010,with a trend of first increasing and then decreasing,decreasing from 7.10 W·m-2 in 2007 to 5.66 W·m-2 in 2015.This is basically consistent with the change trend of total fuel consumption.Industrial sources and road mobile sources are the biggest factors affecting the total change of man-made heat emissions.From 2007 to 2015,the anthropogenic heat emission in most of the Pearl River Delta region was 0?20 W·m-2,high-value areas(>20 W·m-2)are mainly distributed in urban agglomerations in the heart of the Pearl River Delta region,the area and rate of shrinking of high-value areas reached the maximum during 2010 to 2012.At the same time,this study also uses another anthropogenic heat emission calculation method-the source inventory method to calculate the 2012-20015 anthropogenic heat emission inventory in the Pearl River Delta region.The result is consistent with the result of anthropogenic heat calculation by statistical regression method.Further carry out uncertainty analysis on the anthropogenic heat emission inventory,the uncertainty range of the 95%confidence interval for total anthropogenic heat is-16%to 49%.Among them,the uncertainty in the emission estimation of the power plant category is the smallest,ranging from-13%to 16%,and the uncertainty of the industrial source is the highest,at-46%to 73%.This study sets up a number of programs to explore the impact of different man-made heat inputs on meteorological factors.With the increase of anthropogenic heat emissions,the temperature of 2 meters will rise,and its influence on the temperature in January is greater than that in July;The emission of anthropogenic heat significantly reduces the relative humidity in the environment in urban areas,enhance the heat convection near the ground and increase the wind speed,if only considering the improvement of wind speed simulation,the effect of man-made heat emission on wind speed optimization is very small.At the same time,the high-resolution gridded anthropogenic heat emission inventory scheme reduces the average deviation of each site This shows that the man-made heat list calculated by a more practical statistical regression method can improve the model's simulation performance of meteorological elements.During the high temperature heat wave,anthropogenic heat will increase the temperature and surface temperature of 2m in urban areas by 1?and 1?1.5?,respectively.The emission of anthropogenic heat will aggravate the high temperature in the city,but will also reduce the temperature difference between day and night.After the increase of anthropogenic heat,the geothermal flux decreases,and the urban heat storage at daytime and nighttime decreases by 2 W·m-2 and 6-10 W·m-2,respectively.The sensible heat increases by 10?50 W·m-2 during the day,and the emission of point source anthropogenic heat in some areas can even cause the sensible heat to increase by 300 W·m-2.The latent heat flux decreases by 2W·m-2 in the central area of the Pearl River Delta,and increases by 2?4W·m-2 in the peripheral areas.The emission of anthropogenic heat caused an increase of about 0.2?1 m·s-1 in the wind speed of 10m,and an obvious horizontal airflow convergence phenomenon was formed on the underlying surface of the Pearl River Delta city,which indicated that the emission of anthropogenic heat significantly aggravated the urban heat island circulation.The temperature above the boundary layer decreased by about 0.3-0.5?,and the water vapor mixing ratio near the ground increased by about 0.4 g·kg-1 due to the sinking of the downward airflow from about 1 to 2 m·s-1 southerly in the height of the boundary layer.The anthropogenic heat flux in the Pearl River Delta region is discharged to the surface,which strengthens the heat convection near the ground.Thermal convection will increase the vertical movement of airflow in the atmospheric boundary layer under the background of weak southerly winds,and the vertical movement of thermal convection under strong background wind will hinder the movement of horizontal airflow.For the simulated urban heat island intensity,the gridded anthropogenic heat list calculated by inputting the statistical regression method can reduce the average relative deviation and improve the simulation performance.This may be due to the use of a variety of space allocation methods in the statistical regression method,which makes the space allocation of anthropogenic heat more objective and accurate. |
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