| Because of thedevelopment of urban, urbanization is quite obviously in cities of China these recent years. The population of cities and towns is almost one half of the total population of China till December2011. This is a milestone of urbanization of China. However urbanization might bring a lot of problems such as lack of construction land, the incensement of anthropogenic heat release and etc. All the problems mentioned above may affect the outdoor thermal comfort. How to keep the balance of construction and protection of the environment is an important issue that should be well considered in mega Chinese cities.The lack of construction land is a common problem which mainly happens in the built up area of mega cities. To increase the building density or volume rate of the built up area might be some of the solutions. Gradually, more and more heat will be stored and accumulated inside the urban because of urbanization, which will cause the widely known Urban Heat Island phenomenon (UHI). As in Wuhan, the annual average air temperature has increased2-3℃in recently years because of the urbanization. To alter the land use from water to land is another solution to the problem of lack of construction land in many cities of China. Wuhan, which is one of the mega cities in China and famous for its large amount of water area is of course has changed a lot of water area to land. From1965to2008, inside the built up area of Wuhan there is almost130.5km2water area has been changed to land, which is almost1/4of the former water area inside the built up area. Land use alteration will affect the urban climate and thermal environment. Therefore, the study of strategy of urban planning and design based on urban climate and thermal environment is quite important and needed.This study is based on the cases set in Wuhan, which is located in the geographic center of China along Yangtze River. We discussed the problem of lack of construction land in Wuhan and also the gradually increase of annual average air temperature of Wuhan. This study is applied the mesoscale meteorology model to do simulation, in order to quantitatively analyze the impact of changes based on standards of Wuhan’s planning in year2020for building density, volume rate, and water area on urban climate and thermal environment. To achieve that we set5cases in different building density,5cases in different volume rate, and2cases of different water area in Wuhan and compare the air temperature at2m height above ground level, relative humidity, wind velocity, long wave radiation, short wave radiation, sensible heat flux, latent heat flux, and urban heat island intensity of each case.The mesoscale meteorology model which we applied in this study is named WRF (Weather Research and Forecasting) model. For finer accuracy, we also applied the urban canopy model (UCM) coupled with WRF in this study to simulate the processes of reflection of short wave and long wave radiation among sky, buildings, and roads. For validation, we have collected data from field measurement and will do the comparison between measurement data and simulated data.A brief introduction of the background and motivation of this study is given in Chapter1. Reviews of this study field in and abroad are given in Chapter2. The method of this study with some related details such as boundary conditions, case settings and etc. are given in Chapter3. The studies of impact of changes of building density, volume rate, and water area on urban climate and thermal environment are given in Chapter4,5, and6, respectively.7hypothetical cases set to forecast the changes of climate and thermal environment of Wuhan with the rapid development in next decades are given in Chapter7. The discussion and conclusion are given in Chapter8. |
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