The contribution of urbanization to the changes in growing season indices (e.g., the start date of the growing season, Ds) in Shanghai, eastern China, for the period 1873–2013 is assessed. The urban-related Ds advancement (referred to as the urbanization contribution, UC) is reconstructed based on the changing urban-land fraction within a grid box around Shanghai for 1873–2013. After removing the UC from the raw Ds time series, the secular trend (ST) representing the long-term climatic warming and multidecadal variability (MDV) representing an oscillatory component with a period of several decades are obtained by using the Ensemble Empirical Mode Decomposition (EEMD) method. Results show that the UC is comparable with the contribution of the ST for the period 1873–2013, when Ds exhibits an advancing rate of about 0.44 days per decade. MDV plays an important role in regulating changes in Ds on the decadal timescale, e.g., with a contribution of about 56.1% for 1981–2013.
近几十年随着城市化的高速发展，上海地区保持着较快的升温趋势，导致该地区气候学生长季开始日期呈现提前的趋势。借助于1873-2013年上海地区逐日温度记录以及城市土地变化百分比数据，评估了城市化对生长季开始日期变化的贡献。结果表明，对于整个时段来说，生长季开始日期提前的速率约为0.44天/10年。其中城市化对生长季开始日期提前的贡献可能与温室气体造成的生长季开始日期提前的贡献大致可比。而在近30年（1981-2013年），多年代际变率对生长季开始日期提前的贡献最大，约为56.1%。