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Arid Land Geography ›› 2024, Vol. 47 ›› Issue (2): 203-213.doi: 10.12118/j.issn.1000-6060.2023.124

• Climatology and Hydrology • Previous Articles     Next Articles

Attribution analysis of runoff change in the Datong River Basin, Qinghai-Tibet Plateau

WANG Shuzhi1(), WEN Deping2()   

  1. 1. Hydrology and Water Resources Forecast Center of Qinghai Province, Xining 810001, Qinghai, China
    2. Qinghai Province Flood and Drought Disaster Prevention Service Center, Xining 810001, Qinghai, China
  • Received:2023-03-21 Revised:2023-08-01 Online:2024-02-25 Published:2024-03-14
  • Contact: WEN Deping E-mail:qhswjcb@163.com;wendeping5@163.com

Abstract:

The Datong River Basin is located on the northeastern edge of the Qinghai-Tibet Plateau and is a sensitive and fragile ecological environment. It is of great significance to conduct research on the evolution and attribution of water resources in changing environments for the protection of the water ecological environment in the area and the construction of water ecocivilization. Statistical methods such as linear regression, concentration degree, concentration period, ordered clustering test, and wavelet analysis were used to analyze the characteristics of annual variation, seasonal distribution, periodicity, and abrupt changes in basin runoff. On the basis of the cumulative slope change rate method and double cumulative curve, the effects of climate factors and human activities on runoff changes were quantitatively evaluated. The results showed the following: (1) The climate in the Datong River Basin had warmed and humidified significantly in the past 60 years, with increases in average annual temperature, precipitation, and potential evapotranspiration of 0.42 ℃·(10a)-1, 8.9 mm·(10a)-1, and 5.6 mm·(10a)-1, respectively. The annual runoff showed a decreasing trend, with a tendency rate of 0.67×108 m3·(10a)-1. (2) The concentration degree and uneven coefficient of runoff showed a weak downward trend, and the increasing dry season runoff trend was evident. The seasonal distribution was more uniform, and the concentration period showed a delayed trend, with a delay rate of 3.0 d·(10a)-1. (3) The annual runoff oscillated significantly at a scale of approximately 44 years, and the mutation occurred in 1990. After the mutation, runoff decreased by 3.52×108 m3. The distribution of glaciers in the basin showed a decreasing trend, whereas the vegetation cover did not show a significant change. (4) The contributions of climate and human activities to the runoff decrease in the Datong River were -17.7% and 117.7%, respectively. Precipitation was the main source of water supply in the Datong River Basin, and interbasin water transfer was the main driving factor for runoff reduction.

Key words: runoff evolution, cumulative slope change rate method, climate change, human activities, Datong River Basin