The impact of drought on vegetation conditions within the Damqu River Basin, Yangtze River Source Region, China

PLoS One. 2018 Aug 24;13(8):e0202966. doi: 10.1371/journal.pone.0202966. eCollection 2018.

Abstract

Drought and vegetation conditions within the Damqu River Basin, part of the Yangtze River Source Region (YRSR), are assessed here using the standardized precipitation index (SPI), the standardized precipitation evapotranspiration index (SPEI), the normalized difference vegetation index (NDVI), and the leaf area index (LAI). We utilized Sen's method, least squares regression method, linear regression and Pearson's correlation analysis to study variations in drought and vegetation indices and the drought effect on vegetation between 1988 and 2015. Results reveal that droughts occurred at a 25% frequency over this period; SPI and SPEI analyses show that 1994, 1999, 2005, and 2010 were change points and that the basin was characterized by varying drought and humidity trends. Subsequent to 2010, both SPI and SPEI decreased within the basin, while 1995, 2000, 2004, and 2010 were change points for NDVI and LAI while the watershed exhibited variable trends in vegetation reduction and increase. The NDVI-annual values of 63.36% regions and the LAI-summer values of 68.39% areas within the basin were decreased during 1988-2015 and 2000-2015, respectively. Subsequent to 2010, both NDVI and LAI decreased within the basin and significant positive correlations at inter-annual and inter-summer time scales were seen in both drought and vegetation indices; drought has exerted a lag effect on vegetation as shown by significant positive correlations between annual SPI/SPEI values and following year NDVI/LAI values.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • China
  • Droughts*
  • Ecosystem*
  • Environmental Monitoring*
  • Plant Development*
  • Rivers*
  • Seasons

Grants and funding

Support was provided by: 1) the Key Foundation Project of Basic Work of the Ministry of Science and Technology of China (2012FY111400), to LSL [http://program.most.gov.cn/]; 2) the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA20040200), to YLZ [http://www.bmrdp.cas.cn/alzx/]; 3) National Natural Science Foundation of China (No. 41671104), to LSL [http://www.nsfc.gov.cn/]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.