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运用世界粮农组织推荐的Penman-Monteith方程和1980~2008年黄土高原不同经纬度18个气象站气象要素观测数据,研究了黄土高原地区不同气象站点参照腾发量的时空变化特征。结果表明:1980~2008年黄土高原参照腾发量年平均值为874.74~1129.79mm,并随着纬度从北到南和经度从东到西有逐渐增加的趋势;20多年间绝大部分研究点的ET0呈逐年增加趋势,其变化倾向率为4.04~48.25mm/10a,无论包头、横山、绥德、延安、洛川、固原、环县和临汾等地降雨量逐年减少,还是东胜、榆林、民和、靖远、海原和长治等地降雨量逐年增加,可见黄土高原的干旱化正在加剧。黄土高原各气象站点的参照腾发量年内最大值均出现在6、7月;5~8月的ET0占全年的比重为52.9%~59.2%,比重随着纬度的增加而减少。
Based on the Penman-Monteith equation recommended by the World Food Program (FAO) and meteorological observation data of 18 meteorological stations at different latitudes and longitudes from 1980 to 2008, the spatial and temporal variations of reference evapotranspiration at different meteorological stations in the Loess Plateau were studied. The results show that the annual average evapotranspiration of Loess Plateau from 1980 to 2008 is 874.74-1129.79 mm, and increases gradually from east to west with latitude from north to south. For most of the 20 years, Of ET0 showed an increasing trend year by year with a trend of change rate of 4.04-48.25mm / 10a, no matter the rainfall in Baotou, Hengshan, Suide, Yan’an, Luochuan, Guyuan, Huanxian and Linfen decreased year by year, or Dongsheng, Yulin The rainfall in Minhe, Jingyuan, Haiyuan and Changzhi increased year by year, showing that the aridification of the Loess Plateau is intensifying. The maximum values of reference evapotranspiration of all meteorological stations in the Loess Plateau all occurred in June and July; the proportion of ET0 from May to August accounted for 52.9% -59.2% of the whole year, and the proportion decreased with the increase of latitude.