Abstract:

For past 20 years, rapid urbanization and industrialization in Wuxi, not only made a significant increase in builtup area and a rapid drop in arable land, but increased energy consumption, car ownership, and industrial emissions year by year. The characteristics of climate changes and their response to urbanization effects in Wuxi City during last nearly 60 years were analyzed, using the meteorological data of Wuxi from 1995 to 2012. The results showed that the average temperatures, maximum and minimum temperatures, and the extreme maximum and minimum temperatures all had significant upward tendency, and the high temperature days increased year by year, especially after 1980, while the low temperatures, diurnal temperatures and the average relative humidities all had a downward tendency. There were few changes in precipitation, but the rainfall was not in uniform distribution. The drizzle frequencies, the low cloud cover and the sunshine hours were all in downward trend. Urban Heat Island (UHI) was more significant throughout the year, especially in Winter. The urban temperatures were 03℃-08℃ higher than the regional average, but the temperatures of area around lake region and country were below the regional average of 0℃-08℃. There was an increase in haze days but not foggy days, the haze days were mostly more than 30 days and the foggy days in 10 days or so after 2003. Urbanization and industrialization caused the UHI effect and urban dirty island effect (UDI effect), changing the surface conditions, and then affected the spatial and temporal distribution of temperature, relative humidity, and rainfall, which led to an increase in haze days and decrease in foggy days