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利用涡度相关系统、土壤水分TDR传感器,于2014年7月—2015年6月连续测定了民勤绿洲荒漠过渡带退化梭梭人工林蒸散量,研究不同天气条件下梭梭人工林的蒸散对外界环境因子的响应.结果表明:梭梭人工林晴天蒸散量日变化具有明显的季节变化规律.梭梭人工林蒸散量日变化幅度在生长季初期逐渐增大,在生长旺盛期达到最大峰值(0.07mm·h~(-1)),而后逐渐减小,至12月达到最低峰值(0.01 mm·h~(-1)).不同天气条件下梭梭人工林蒸散日变化波动幅度差异较大,阴天蒸散日变化波动幅度最小,降水后蒸散波动明显增高,强降水(>9 mm·d~(-1))后日蒸散量显著增加至雨前的28倍,然后逐渐减少,并持续4个晴朗日后恢复至雨前蒸散量.在整个观测年,梭梭人工林蒸散总量为108 mm,占降水总量的98%,土壤水是梭梭人工林蒸散的水源,为主导因子.净辐射、光合有效辐射、空气温度、水汽压饱和差是决定植被用水和大气边界层水传输的气象动力,为显著影响梭梭人工林蒸散的主要因子.利用日蒸散量与环境因子数据建立了蒸散与土壤含水量和小气候因子的多元回归方程,拟合度(R2)高达0.80.
Using evapotranspiration correlation system and soil moisture TDR sensor, the evapotranspiration of degraded Haloxylon ammodendron plantation in the transitional zone of Minqin oasis was continuously measured from July 2014 to June 2015, and the evapotranspiration of Haloxylon ammodendron plantation was studied under different weather conditions The results showed that the diurnal variation of sunny evapotranspiration in Haloxylon ammodendron plantation had obvious seasonal variation.The diurnal variation of evapotranspiration of Haloxylon ammodendron plantation increased gradually during the early growing season and reached its peak during vigorous growing season 0.07mm · h ~ (-1)), then decreased gradually and reached the lowest peak value (0.01 mm · h -1) in December. The diurnal variations of diurnal variations of Haloxylon ammodendron plantation varied greatly under different weather conditions , The variation of diurnal variation of evapotranspiration over the cloudy day was the smallest, and the variation of evapotranspiration after precipitation was significantly higher. The diurnal variation of evapotranspiration after heavy precipitation (> 9 mm · d -1) significantly increased to 28 times of that before rain, and then decreased gradually During the whole observation year, total evapotranspiration of Haloxylon ammodendron plantation was 108 mm, accounting for 98% of the total precipitation. Soil water was the source of evapotranspiration of Haloxylon ammodendron plantation and was the dominant factor. Net radiation, photosynthetically active radiation, air temperature, vapor pressure saturation difference It is the main factor that determines the transpiration of plantation water and atmospheric boundary layer water, which is the main factor that influences the evapotranspiration of Haloxylon ammodendron plantation.Multiple regression equations of evapotranspiration and soil moisture content and microclimate factors are established by using daily evapotranspiration and environmental factors data, fitting Degree (R2) up to 0.80.