杉木人工林地土壤水分蒸发的时空变化特征

Spatial and temporal variation characteristics of soil moisture evaporation in Chinese fir plantation

为了研究土壤水分蒸发规律,做好蓄水保墒,减少水分的非生产消耗,需要了解水分运动规律。本实验利用2012年湖南会同定位观测站第Ⅱ集水区实测数据,研究杉木人工林地土壤水分蒸发日变化、月变化、及不同坡位的变化规律。结果表明:土壤水分观测日最大分时蒸发量发生在9:00～11:00时段,月均蒸发量在6月中旬左右达到最大峰值;春季3～5月期间土壤含水量的平均变化程度较小,而夏季6～7月期间土壤含水量的平均变化程度较大;不同坡位因土壤层厚度、空气流动程度及林下植被凋落物的种类和混合比例不同,其土壤水分蒸发量呈现明显差异。结合这些特点,试图分析其形成的原因,为后期研究提供了参考方向。

In order to study soil moisture evaporation law,complete storage of soil moisture and reduce water consumption,it is important to know about water motion law.The laws of diurnal variation,monthly variation and variation in different slope positions of soil water evaporation in Chinese fir plantation were investigated by using the observational data of Chinese fir plantation collected in the 2nd catchment area in Huitong National Field Station for Scientific Observation in 2012.The results show that the largest timeshare evaporation occurred during the 9：00 ～ 11：00 period in the observation day,the monthly evaporation reached a maximum peak around mid-June;the average change degree of soil moisture during the spring from March to May was smaller,while that during the summer from June to July was bigger;the soil moisture evaporation showed differences in different slope positions due to the soil thickness,the types and mixing ratio of the under-storey litters,the degree of air flow and so on.Combining these features,the formation causes of soil moisture evaporation were studied in order to provide a reference direction for later researches.