红壤坡地农业景观(旱季)地表界面水分传输研究——I.土壤-大气界面水分传输
Study on surface water transport in agricultural landscape on the slop lands of red soil(dry season)I.Water transport at soil-atmosphere interface
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摘要: 定位观测研究红壤坡地土壤-大气界面水分传输结果证明,不同地表植被群落构建和不同农业利用景观土壤蒸发量有差异,但水汽传输通量的动态变化规律一致,土壤蒸发量日变化为典型单峰曲线。界面水分传输通量受诸多因素影响,当地表植被群落稳定、作物因素影响较小时,水汽通量除受气候条件影响外还明显受土壤含水量特别是表层土壤含水量的影响。界面水汽传输通量与净辐射能呈显著正相关,与环境温度有很好的相关性,温度越高其蒸发越强,与空气湿度呈极显著负相关。界面水汽传输通量主要受0~20cm 表层土壤水分控制,二者间存在线性关系。土壤蒸发量占系统蒸散量的1/3,该部分非生产性水分消耗有控制降低的可能,可通过土壤培肥、灌溉控制、物理障碍等手段抑制土壤蒸发。Abstract: A located observation and study of water transport at soil-atmosphere interface was conducted. The results show that there are differences in soil evaporation among different agricultural cultivations while no difference in the dynamic variation of water vapor transfer flux.The daily variation curve of soil evaporation is a typical single peak curve.Many factors may affect the surface water transport.When surface vegetational typ es are stable and the effects of crop are not remarkable,the water transfer at soil-atmosphere interface is affected not only by climatic condition but also apparently by soil water contents(0~20cm).The water vapor transfer through interface is significantly positively correlated with the net radiation and is corelated with the environmental temperature.It is also affected by water potential and has a highly significant negative corelation with the air humidity.Therefore,the water vapor transfer at interface is mainly controlled by soil surface(0~20cm)water contents.Their relationship has a linear correlativity.The amount of soil evaporation is 1/3 of the total field evapotranspiration.There are potentials for controlling the consumption to these none productive water moisture.Measures such as soil-manuring,irigation-controlling,physical obstacle of preventing soil evaporation are presented.