沙坡头人工植被区和流动沙丘上热量平衡观测研究

Observation Research on Heat Balance of the Artificial Vegetation and Bare Sand Dunes in Shapotou Area

采用流动沙丘上人工植被和裸露流动沙丘下垫面近地层微气象实测资料，应用波文比法，计算了近地层感热和潜热通量２），并与作者在防风林干旱裸田和湿润小麦植被农田的结果进行比较分析。结果表明：在雨季的沙坡头地区流动沙丘人工植被上净辐射通量较强，可达６００Ｗ．ｍ－２以上，而净辐射的７０％左右的能量用于地表的蒸散，而感热散失和土壤贮存能量各占１５％左右；裸露流动沙丘上由于地表反射率大而净辐射通量小于植被区，可达４００Ｗ．ｍ－２，净辐射的６０％左右的能量用于地表蒸发，感热散失量占１５％左右，土壤热贮存占２５％左右。在干旱防风林棵田中，净辐射的４５％左右的能量作为感热而散失，蒸腾潜热只占３５％左右，而土壤贮存的热量占２０％左右。在湿润的小麦植被农田上，几乎净辐射的全部能量都用于潜热蒸散。特别在初夏的干燥天气及热平流较强时，潜热蒸散项甚至大于净辐射项，而感热几乎全天为负值，土壤热通量只占净辐射的５％左右。

he heat balance character of artificial vegetation on sand dunes in Shapotou region were calculated and analysed. The results show that: (1) about 70 percent of net radiation is dispersing as latent flux,about 15 percent is dispersing as sensible heat flux,and about 15 percent is stored in the soil in the artificial vegetation region on sand dunes. (2) about 60 percent of net radiation is dispersing as latent heat flux,about 15 percent is dispersing as sensible heat flux,about 25 persent is stored in the soil in the bare sand dunes. (3) the water vapour content is higher than that of another dry area in Shapotou region.