Arid Zone Research ›› 2019, Vol. 36 ›› Issue (4): 973-979.doi: 10.13866/j.azr.2019.04.22

• Water and Climate • Previous Articles     Next Articles

Spatiotemporal Variation and Driving Factors of Pan Evaporation in the Weihe River Basin

ZHANG Peng-fei1, ZHAO Guang-ju1,2, MU Xing-min1,2, GAO Peng1,2, SUN Wen-yi1,2   

  1. 1. State Key Laboratory of Soil Erosion and Dryland Framing on the Loess Plateau,Northwest A&F University, Yangling 712100,Shaanxi,China;
    2. Institute of Soil and Water Conservation,Chinese Academy of Science & Ministry of Water Resources, Yangling 712100,Shaanxi,China
  • Received:2018-10-08 Revised:2018-12-12 Published:2025-10-18

Abstract: It is better to quantitative assess the spatiotemporal variation and driving factors of pan evaporation for understanding the hydrological cycle and water resources management.In this study,it was attempted to use the data of daily pan evaporation observed with 20 cm pan from 1978 to 2002 and E-601 evaporator from 1985 to 2015 at 21 meteorological stations in the Weihe River Basin.A linear regression model was used to reconstruct the evaporation data at the observation sites.Spatiotemporal change of pan evaporation was analyzed using the Mann-Kendall test.Sensitivity analysis was employed to evaluate the contribution of meteorological factors to pan evaporation.The results showed that the multi-year average evaporation capacity of the evaporating dish in the study area was lower than that in the Yellow River Basin and the pan evaporation values were 1 015.5-1 705.6 mm.the mean annual pan evaporation decreased from the north to the south.The annual mean evaporation increased generally with an increase rate of 1.371 mm·a-1 in the whole watershed. The pan evaporation was the most sensitive to the actual vapor pressure.Temperature was the dominant factor affecting pan evaporation,and its contribution rate was approximately 304.5%.

Key words: pan evaporation, spatiotemporal variation, sensitivity analysis, driving factor, Weihe River Basin