PROGRESS IN GEOGRAPHY ›› 2020, Vol. 39 ›› Issue (2): 243-254.doi: 10.18306/dlkxjz.2020.02.006

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Spatiotemporal changes of regional ecological risks in Shaanxi Province based on geomorphologic regionalization

LIU Di, CHEN Hai*(), GENG Tianwei, ZHANG Hang, SHI Qinqin   

  1. College of Urban and Environmental Sciences/Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Northwest University, Xi'an 710127, China
  • Received:2019-03-14 Revised:2019-05-16 Online:2020-02-28 Published:2020-04-28
  • Contact: CHEN Hai E-mail:chw@nwu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(41671086);National Natural Science Foundation of China(41871185)

Abstract:

Land surface elements such as land use / land cover are in constant change and dynamic balance, driving the changes of global ecological processes and forming the regional differentiation of landscape, which cause many ecological risks under multi-source stresses. Based on a probability-loss risk model, a multiple hazards and potential ecological damage approach was used to construct a regional ecological risk evaluation system of Shaanxi Province. After identifying multiple hazard types from the perspective of geomorphologic regionalization, potential ecological damages were synthesized by taking landscape pattern and ecosystem services value losses as related factors. The spatial and temporal differentiation of individual risk factors and regional ecological risks in Shaanxi Province between 2000 and 2015 were analyzed. Meanwhile, the spatial and temporal changes of ecological risks were demonstrated from the perspective of geomorphologic regionalization and risk gravity model. Several conclusions were drawn from this analysis: 1) In 2000 and 2015, the multiple hazards index values of Shaanxi Province were 0.3837 and 0.4558, respectively, with an increase of 18.79%. Multiple hazards presented the spatial pattern of high in the north and south and low in the middle, with a W-shaped distribution along the north-south axis. Potential ecological damages were 0.5537 and 0.6270, up by 13.24%. Except for the southern part of the Loess Plateau and the eastern part of the Qinling Mountains, potential ecological damages were high. The regional ecological risks were 0.2429 and 0.2865, rising by 17.95%, and presented a spatial distribution pattern of "three high value areas sandwiched by two low value areas". 2) The ecological risks of the Qinling-Daba Mountains were low and the change rate of risks was small. The change rate of risks of the Loess Plateau and the sandification transitional zone was moderate, and the latter was facing a high risk. The Hanjiang Basin had the highest risks and the Hanjiang Basin and Guanzhong Plain took the first and second places in the change rate of risks, respectively. The risk gravity centers of the Loess Plateau and the sandification transitional zone both moved to the southwest, the risk gravity centers of the Guanzhong Plain and the Qinling Mountains moved significantly to the east, and the risk gravity centers of the Hanjiang Basin and the Daba Mountains jumped to the southeast.

Key words: regional ecological risks, geomorphologic regionalization, risk gravity, multiple hazards, potential ecological damage, Shaanxi Province