Arid Zone Research ›› 2021, Vol. 38 ›› Issue (2): 303-313.doi: 10.13866/j.azr.2021.02.02

• Weather and Climate • Previous Articles     Next Articles

Prediction of vapor pressure deficit in Northwest China based on exponential and ARIMA models

HAN Yonggui1,2(),HAN Lei1,2,3(),HUANG Xiaoyu1,2,GAO Yang1,2   

  1. 1. School of Recourses and Environment, Ningxia University, Yinchuan 750021, Ningxia, China
    2. China-Arab Joint International Research Laboratory for Featured Resources and Environmental Governance in Arid Regions, Yinchuan 750021, Ningxia, China
    3. Institute of Environmental Engineering, Ningxia University, Yinchuan 750021, Ningxia, China
  • Received:2020-08-24 Revised:2020-10-13 Online:2021-03-15 Published:2021-04-25
  • Contact: Lei HAN E-mail:ifhani@163.com;layhan@163.com

Abstract:

Vapor pressure deficit (VPD) is a key factor affecting water transport in the soil-plant-atmosphere continuum; in the context of global climate change, predicting VPD has practical significance for vegetation management and risk assessment of meteorological disasters affecting agriculture and forestry in Northwest China. Using VPD data from five provinces (regions) in Northwest China from 1990 to 2019, we analyzed the characteristics of VPD interannual variation and periodic variation using trend and wavelet analyses. The optimal sample step and prediction step were selected; exponential models and autoregressive integrated moving average (ARIMA) models were used to simulate and predict VPD in Northwest China. Among the five provinces, Ningxia had the highest trend slope of VPD [0.036 kPa·(10a)-1], followed by Xinjiang [0.033 kPa·(10a)-1]. The annual average VPD in Xinjiang was the highsest at 0.61 kPa, followed by Ningxia, Shaanxi, Gansu, and Qinghai (0.54 kPa, 0.48 kPa, 0.46 kPa, and 0.36 kPa, respectively). Over the past 30 years, the VPD in Northwest China followed an upward trend; Ningxia and Xinjiang had the largest increases in VPD at 0.036 and 0.033 kPa·(10a)-1, respectively, followed by Gansu [0.026 kPa·(10a)-1], Qinghai [0.021 kPa·(10a)-1], and Shaanxi [0.012 kPa·(10a)-1]. Compared with the exponential model, the root mean square error (RMSE) of the ARIMA model was reduced by 42.3%, the R2 was increased by 11.1%, and the Nash-Sutcliffe efficiency coefficient increased by 17.7%. Thus, the VPD prediction accuracy was effectively improved. The VPD in Northwest China is expected to increase by varying degrees; Ningxia and Xinjiang showed the highest VPD growth rates of 9.5% and 8.9%, respectively.

Key words: vapor pressure deficit, exponential smoothing, ARIMA model, prediction, Northwest China