Journal of Geographical Sciences ›› 2021, Vol. 31 ›› Issue (8): 1123-1139.doi: 10.1007/s11442-021-1888-y

• Special Issue: Ecohydrology • Previous Articles     Next Articles

Attribution of trends in meteorological drought during 1960-2016 over the Loess Plateau, China

GUO Mengyao1,2(), SHE Dunxian1,2,*(), ZHANG Liping1,2, LI Lingcheng3, YANG Zong-Liang3, HONG Si1,2   

  1. 1. State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
    2. Hubei Key Laboratory of Water System Science for Sponge City Construction, Wuhan University, Wuhan 430072, China
    3. Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78712-1692, USA
  • Received:2020-09-22 Accepted:2021-05-10 Online:2021-08-25 Published:2021-10-25
  • Contact: SHE Dunxian E-mail:mengyao_guo@whu.edu.cn;shedunxian@whu.edu.cn
  • About author:Guo Mengyao (1994-), PhD Candidate, specialized in atmosphere-ecosystem interactions. E-mail: mengyao_guo@whu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(41877159);The National Key Research and Development Program of China(2017YFA0603704);The Scholarship from China Scholarship Council(CSC), No(201906270109)

Abstract:

This study uses two forms of the Palmer Drought Severity Index (PDSI), namely the PDSI_TH (potential evapotranspiration estimated-by the Thornthwaite equation) and the PDSI_PM (potential evapotranspiration estimated by the FAO Penman-Monteith equation), to characterize the meteorological drought trends during 1960-2016 in the Loess Plateau (LP) and its four subregions. By designing a series of numerical experiments, we mainly investigated various climatic factors' contributions to the drought trends at annual, summer, and autumn time scales. Overall, the drying trend in the PDSI_TH is much larger than that in the PDSI_PM. The former is more sensitive to air temperature than precipitation, while the latter is the most sensitive to precipitation among all meteorological factors. Increasing temperature results in a decreasing trend (drying) in the PDSI_TH, which is further aggravated by decreasing precipitation, jointly leading to a relatively severe drying trend. For the PDSI_PM that considers more comprehensive climatic factors, the drying trend is partly counteracted by the declining wind speed and solar radiation. Therefore, the PDSI_PM ultimately shows a much smaller drying trend in the past decades.

Key words: meteorological drought, potential evapotranspiration, contribution, sensitivity, Loess Plateau, climatic factor