摘要
饱和水汽压差是土壤-植被-大气连续体水分传输过程的关键影响因素,在全球气候变化背景下,预测西北地区饱和水汽压差,对于植被恢复和农林业气象灾害风险评估具有重要的现实意义。基于西北五省(区)1990—2019年月饱和水汽压差值,采用趋势分析和小波分析等方法研究了西北地区饱和水汽压差年际变化特征和周期性变化规律;采用指数模型和ARIMA模型,筛选最佳样本步长和预测步长,对西北地区饱和水汽压差进行模拟和预测。结果表明:(1)西北五省(区)中,新疆年均饱和水汽压差最高,其次为宁夏、陕西、甘肃和青海;近30 a整体上西北地区饱和水汽压差呈上升趋势,其中宁夏和新疆饱和水汽压差上升幅度最大,分别为0.036 kPa·(10a)^(-1)和0.033 kPa·(10a)^(-1),其次为甘肃[0.026 kPa·(10a)^(-1)]、青海[0.021 kPa·(10a)^(-1)]和陕西[0.012 kPa·(10a)^(-1)];(2)西北各省(区),16 a尺度周期对小波方差贡献最大,为饱和水汽压差变化的主周期。此外,陕西、甘肃和新疆还存在24~27 a的周期特征,方差贡献较小;(3)相对于指数模型,ARIMA模型均方根误差平均减少42.3%,决定系数R2平均提高11.1%,Nash-Sutclife效率系数平均提高17.7%,有效提高了饱和水汽压差预测精度;(4)未来一段时间内,西北各地区饱和水汽压差均存在不同程度的升高趋势,以宁夏和新疆地区的饱和水汽压差增幅最为明显,分别为9.5%和8.9%。
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.
作者
韩永贵
韩磊
黄晓宇
高阳
HAN Yonggui;HAN Lei;HUANG Xiaoyu;GAO Yang(School of Recourses and Environment,Ningxia University,Yinchuan 750021,Ningxia,China;China-Arab Joint International Research Laboratory for Featured Resources and Environmental Governance in Arid Regions,Yinchuan 750021,Ningxia,China;Institute of Environmental Engineering,Ningxia University,Yinchuan 750021,Ningxia,China)
出处
《干旱区研究》
CSCD
北大核心
2021年第2期303-313,共11页
Arid Zone Research
基金
国家自然科学基金项目(31760236,31460220)
宁夏自然科学基金项目(2019AAC03043)资助。
关键词
饱和水汽压差
指数平滑
ARIMA模型
预测
西北地区
vapor pressure deficit
exponential smoothing
ARIMA model
prediction
Northwest China