PROGRESS IN GEOGRAPHY ›› 2020, Vol. 39 ›› Issue (9): 1532-1543.doi: 10.18306/dlkxjz.2020.09.010

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Detection of urbanization effect on the climate change in Liaoning Province based on empirical orthogonal function methods

AO Xue1(), ZHAI Qingfei2,*(), CUI Yan1, ZHOU Xiaoyu1, SHEN Lidu1, ZHAO Chunyu1, Ning Xilong3   

  1. 1. Shenyang Regional Climate Center of Liaoning Province, Shenyang 110166, China
    2. Liaoning Weather Modification Office, Shenyang 110166, China
    3. Fuxin Meteorological Service, Fuxin 123100, Liaoning, China
  • Received:2019-09-20 Revised:2019-12-12 Online:2020-09-28 Published:2020-11-28
  • Contact: ZHAI Qingfei E-mail:aoxuefyh@163.com;15840322495@163.com
  • Supported by:
    Scientific Research Project of Liaoning Meteorological Bureau in 2018(BA201803);Scientific Research Project of Liaoning Meteorological Bureau in 2018(201818);Science and technology Plan Project in Liaoning Province(2019-MZ-199);Science and technology Plan Project in Liaoning Province(2019-ZD-0859)

Abstract:

Based on the daily climate data and socioeconomic data from 1961 to 2017, a new urbanization index was established and the influence of urbanization on climate change of Liaoning Province was analyzed. The results show that the temperature in Liaoning Province exhibits a significant warming trend, and the rate of warming at the national stations is obviously faster than at the rural stations. The influence of urbanization from large to small are in the following order: The average minimum temperature > the average temperature > the average maximum temperature. The contributions of urbanization in the four seasons are as follows: Autumn > winter > summer > spring. In terms of spatial distribution, the high-value areas affected by urbanization are located in the central and western regions of Liaoning Province, which are basically in line with the urbanization development level of the province. Urbanization does not have a spatially consistent influence on temperature—it plays a warming role in most areas, especially in areas with high economic development level such as Shenyang and Dalian, but it also has a restraining effect on the warming of a few stations. Among the temperature indices, urbanization has the most significant influence on the annual and four-season average temperature, with corresponding first mode, and contribution rate over 89%. The spatial correlation of the annual and four-season average temperature has passed the significance test. In addition, urbanization has influence on the mean minimum air temperature and the daily range. In terms of seasonal variation characteristics, the temperature increase in winter and spring is more obvious than that in autumn and summer. The precipitation index basically corresponds to the second mode, and the contribution rate is between 9% and 18%. The influence of urbanization on temperature is stronger than that on precipitation. Combined with the time coefficient, the urbanization effect shows that the precipitation in the spring and winter and the number of days of heavy rain and rainstorm increased slightly, but the number of days of light rain and moderate rain and the precipitation in the summer and autumn decreased. Urbanization has a two-sided influence on precipitation. On the one hand, urbanization reduces annual precipitation and precipitation of small magnitude; on the other hand, it increases extreme precipitation events.

Key words: urbanization, EOF, climate change, Liaoning Province