Investigation of the relationship between precipitation extremes and sediment discharge production under extensive land cover change in the Chinese Loess Plateau

Jianjun Zhang, Guangyao Gao, Bojie Fu, Hoshin V. Gupta

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

To quantify the effects of rainfall and catchment characteristics on sediment yield is of essential importance for sustainable land management. Precipitation extremes are the external cause of the majority of serious soil erosion and suspended sediment yield (SSY) events in the Chinese Loess Plateau (CLP), which has undergone extensive land use/cover change (LUCC). The investigation of the linkage between climate variables and SSY production is crucial to the precise implementation of ecological restoration strategies, thereby reducing soil loss in the CLP. In this study, a partial least squares regression (PLSR) approach is used to investigate this issue using 1961–2015 data from 16 main catchments in the CLP. This period includes the reference period (1961–1979, Period-I), integrated soil conservation project period (1980–1999, Period-II), and the “Grain for Green” program period (2000–2015, Period-III). The results indicate that the dominant climate factors driving SSY are precipitation extremes including maximum precipitation events, heavy precipitation (daily precipitation ≥25 mm), consecutive wet days, erosive precipitation (daily precipitation ≥12 mm), and annual total precipitation. The effects of the precipitation extremes on sediment yield generation are stronger in drier catchments. The influence of the precipitation extremes on sediment generation can be strengthened by cultivation and weakened by revegetation (especially reforestation). The climate-driven sediment yield decreased by 951 t·km−2·yr−1 during Period-II and 505 t·km−2·yr−1 during Period-III in comparison with Period-I. The dominant cause of the sediment yield reduction was LUCC, with the contribution increasing from 73% in Period-II to 92% in Period-III. This study provides a greater understanding of the effects of climate variation and LUCC on sediment yield, and is beneficial for better catchment management.

Original languageEnglish (US)
Article number107176
JournalGeomorphology
Volume361
DOIs
StatePublished - Jul 15 2020

Keywords

  • Attribution analysis
  • Partial least squares regression
  • Precipitation extremes
  • Sediment yield change

ASJC Scopus subject areas

  • Earth-Surface Processes

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