CollectHomepage AdvertisementContact usMessage

Arid Land Geography ›› 2022, Vol. 45 ›› Issue (5): 1637-1648.doi: 10.12118/j.issn.1000-6060.2022.033

• Regional Development • Previous Articles     Next Articles

Geographical exploration of the spatial and temporal evolution of ecological risk and its influencing factors in semi-arid regions: A case of Yanchi County in Ningxia

CHENG Jing1(),WANG Peng2,CHEN Hongxiang1(),HAN Yonggui1   

  1. 1. School of Politics and History, Ningxia Normal University, Guyuan 756000, Ningxia, China
    2. School of Geography Science and Planning, Ningxia University, Yinchuan 750021, Ningxia, China
  • Received:2022-01-25 Revised:2022-03-29 Online:2022-09-25 Published:2022-10-20
  • Contact: Hongxiang CHEN E-mail:958830559@qq.com;670577976@qq.com

Abstract:

As well as being one of the most sensitive regions to global changes induced by human activities, semiarid regions are characterized by drought and low rainfall, sparse vegetation, and extremely fragile ecological environments. It is therefore of great theoretical and practical significance to optimize the landscape pattern of semiarid regions, prevent and manage ecological risks, and promote sustainable and high-quality development via in-depth exploration of the changing laws of landscape patterns in semiarid regions, and clarifying the temporal and spatial evolution characteristics and influencing factors of ecological risks. This study considers Yanchi County in Ningxia, China based on the land use data taken from 2000 to 2020, and uses the landscape pattern index to construct an ecological risk assessment model. Comprehensive research is undertaken on the temporal and spatial evolution of ecological risks and the factors that influence such risks. The results show that: (1) From 2000 to 2020, the area of cultivated land and unused land in Yanchi County decreased; all other land use types showed an increase over this time period. The construction land was seen to have increased the fastest, with an average annual growth rate of 6.90%. The overall land use data shows a rapid expansion in the proportion of construction land, a reduction in the area of cultivated land, an increase in forest and grassland, and an increase in the land area covered by water. (2) From 2000 to 2020, affected by the disturbances to the natural environment and human activities, the number of landscape patches, patch density, landscape shape index and Shannon’s diversity index in Yanchi County increased; in the same period, the largest patch index and spread index decreased, indicating that the landscape became increasingly fragmented and an increase in the complexity and decentralization of land use occurred. (3) From 2000 to 2020, the ecological risk index of Yanchi County decreased from 0.1465 to 0.1312, in which the proportion of higher, high and moderate risk areas decreased by 5.25%, 24.21% and 5.44%, respectively, while the proportion of lower and low risk areas increased by 14.11% and 20.79%, respectively. The distribution pattern of the ecological risk index is high in the north and low in the south. (4) With increasing social demand and the intensification of human activities, the influence of natural factors on the spatial pattern of ecological risks has gradually weakened, whereas the influence of social and economic factors has continued to increase.

Key words: landscape pattern, ecological risk, temporal and spatial evolution, geographic detector, semi-arid regions