PROGRESS IN GEOGRAPHY ›› 2020, Vol. 39 ›› Issue (2): 255-264.doi: 10.18306/dlkxjz.2020.02.007

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Spatiotemporal variation characteristics of surface evapotranspiration in Shanxi Province based on MOD16

WEN Yuanyuan, ZHAO Jun*(), WANG Yanqiang, WANG Yuchun, WANG Jianbang   

  1. College of Geography and Environment Sciences, Northwest Normal University, Lanzhou 730070, China
  • Received:2019-01-18 Revised:2019-03-18 Online:2020-02-28 Published:2020-04-28
  • Contact: ZHAO Jun E-mail:zhaojun@nwnu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(41661084)

Abstract:

Based on the MODIS evapotranspiration (ET) products (MOD 16) and the observation data of meteorological stations, coefficient of variation method and Sen+Mann-Kendall model were used to analyze the spatiotemporal feature, variation trends, and influencing factors of land surface ET and potential evapotranspiration (PET) in Shanxi Province from 2000 to 2014. The main conclusions are as follows: 1) The accuracy of the MOD16-ET (R 2=0.9) of Shanxi can meet the requirements of such research, and can be used to examine the spatiotemporal distribution of surface ET. 2) The mean annual ET and PET were 816.77 mm and 1608.46 mm, respectively. The annual distribution showed a unimodal pattern, which increased first and then decreased; the difference between ET and PET was the largest in May and June when it was the driest in the study area. 3) The annual average ET of the study area was low in northwest Shanxi and high in southeast, while the annual average PET was high in southwest and low in northeast of the study area. The overall difference between the annual average ET and PET was relatively large, which reflects that the whole province was shortage of water, especially in Xinzhou and the west of Lvliang. 4) The interannual variations of ET and PET have been relatively small in the past 15 years. Evapotranspiration showed a decreasing trend, and PET showed an increasing trend, which suggest that the drought was aggravated in Shanxi in the past 15 years. 5) The correlation analysis between evapotranspiration and meteorological factors indicated that the spatiotemporal variation of evapotranspiration was closely related to many climatic factors—they were related to precipitation and relative humidity spatially, and were most closely related to temperature and precipitation temporally.

Key words: evapotranspiration, potential evapotranspiration, spatiotemporal distribution, MOD16, Shanxi Province