Acta Geographica Sinica ›› 2018, Vol. 73 ›› Issue (11): 2117-2134.doi: 10.11821/dlxb201811006

• 气候变化与地表过程 • Previous Articles     Next Articles

Spatio-temporal characteristics of evapotranspiration and its relationship with climate factors in the source region of the Yellow River from 2000 to 2014

YE Hong1(),ZHANG Tingbin1,2,3(),YI Guihua4,LI Jingji5,6,BIE Xiaojuan1,LIU Dong1,LUO Linling1   

  1. 1. Chengdu University of Technology, College of Earth Science, Chengdu 610059, China
    2. The Engineering & Technical College of Chengdu University of Technology, Leshan 614000, Sichuan, China;
    3. Key Laboratory of Geoscience Spatial Information Technology of Ministry of Land and Resources, Chengdu 610059, China
    4. Chengdu University of Technology, College of Management Science, Chengdu 610059, China
    5. Chengdu University of Technology, College of Environmental and Civil Engineering Institute, Chengdu 610059, China
    6. Chengdu University of Technology, Institute of Ecological Resource and Landscape, Chengdu 610059, China
  • Received:2017-12-13 Online:2018-11-25 Published:2018-11-22
  • Supported by:
    National Natural Science Foundation of China, No.41801099, No.41501060; China Geological Survey Project, No.DD20160015-26


Located at the eastern margin of the Tibetan Plateau, the source region of the Yellow River is an important ecological security shelter for economic development in Southwest China, with its unique natural habitats and abundant natural resources. Based on the data of 18 meteorological stations within and around the source region, map of China vegetation types (1:1000,000) and DEM data, and using the methods of trend analysis, relative inter-annual variation and correlation analysis, we selected MODIS evapotranspiration (ET) as the main data source to research the spatio-temporal characteristics of ET and its variation under different land use types as well as its relationship with climate factors in the study area from 2000 to 2014. The results indicate that: (1) the regional differentiation of mean ET over years is obvious, the northern ET is significantly weaker than that of the central and southeastern parts, and the strongest ET is observed in the southeastern part. The multi-year mean value of ET is 538.61 mm/a, and the anomaly relative variation is obvious. In addition, the trend of inter-annual variation of ET decreases firstly and then increases, and the trend variation rate is 0.44 mm/a. (2) During the study period, the ET shows a periodic unimodal trend and peaks in July. Moreover, seasonal differences of ET are apparent in the source region of the Yellow River, and the highest value of ET reaches 188.14 mm/a in summer, followed by spring and autumn, yet the lowest is only 97.15 mm/a in winter. (3) From 2000 to 2014, the value of ET in different types of land use has a similar regular pattern, namely: wetland > forest > grassland > other types > bare land. On the whole, the value of ET in each type of land use increases gradually. (4) According to the correlation analysis results, there are positive correlations between ET and air temperature, as well as between ET and precipitation, while ET has a negative correlation with relative humidity. The effect of precipitation on ET is stronger than that of air temperature. Furthermore, the result of ET driven by different factors demonstrates that the climate-driven region of ET is predominantly precipitation-driven in the source region of the Yellow River.

Key words: evapotranspiration (ET), spatio-temporal characteristics, climatic factors, MODIS, the source region of the Yellow River