Impacts of Urbanization on Precipitation in Taihu Lake Basin, China

Taking Suxichang and Hangjiahu urban agglomerations in Taihu Lake Basin as study areas, the authors explore differences in annual precipitation, flood season precipitation, annual maximum daily precipitation, and rainfall days of different types between cities and suburbs from 1961 to 2006. The authors also investigate the trends of precipitation change by means of Mann-Kendall test and rescaled range analysis. The results show that the amount of precipitation increased with the level of urbanization at spatial and temporal scales. The maximum daily precipitation and the number of rainstorms in urban areas also increased. With further development of urbanization, the increase would continue in the future. The two urban agglomerations with similar level of urbanization and climatic conditions are consistent in terms of all research indicators applied in this paper. The results are basically consistent with many previous studies, while the study area has its own characteristics in that the maximum rainfall generally happened after the plum rains, and that rainstorms often occurred later than they did in other regions. The results above suggest that urbanization has an effect on precipitation, and this is a matter of concern for the cities located in the East Asian Monsoon Region with its heavy rainfall.