PROGRESS IN GEOGRAPHY ›› 2019, Vol. 38 ›› Issue (11): 1783-1792.doi: 10.18306/dlkxjz.2019.11.013

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Impact factors of annual NDVI change in karst mountain areas of Guizhou and Guangxi Provinces

LIU Liangmeizi1,2, ZHAN Chesheng1,*(), HU Shi1, ZHANG Qi1,2   

  1. 1. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-01-07 Revised:2019-04-25 Online:2019-11-28 Published:2019-11-28
  • Contact: ZHAN Chesheng E-mail:zhancs@igsnrr.ac.cn
  • Supported by:
    National Key Basic Research Program of China (973 Program), No(2015CB452701);National Natural Science Foundation of China, No(41571019);National Natural Science Foundation of China, No(51779009)

Abstract:

The karst mountain areas are typical ecologically fragile regions in China. The vegetation is highly prone to degradation and is difficult to recover after that. In this study, we explored the change trend of climatic factors and distinguished the impact factors of annual NDVI change in karst mountain areas, by using stepwise regression, correlation analysis, and residual analysis. From 2002 to 2015, a warm and humid trend was found in the study area, but not significant at the P=95% level. The average annual changes of precipitation and temperature are in the range of -15.6-25.6 mm/a and -0.08-0.06 ℃/a, with an increasing rate of 7.9 mm/a and 0.00035 ℃/a respectively at the regional scale. During the study period, climate variability was the dominating factor of NDVI changes, which accounted for 95% of the annual variations, and the impact of precipitation on NDVI was slightly greater than that of temperature. The residual analysis of NDVI showed that the mean values of NDVI residual and its trend were 0.03 and 0.0007/a in the last 14 years, indicating that the positive effects of human activities were present. Human activities such as urbanization caused a large amount of cultivated land and forest to be occupied by construction land, thus had obvious negative effects on NDVI changes in Bijie, Anshun, Guiyang, Hechi, Liuzhou, and Baise. However, due to the implementation of ecological rehabilitation and reforestation projects, human activities had positive effects on NDVI changes in Liupanshui, Qianxinan, Zunyi, and Laibin.

Key words: vegetation change, climatic factors, human activities, karst mountain areas