红壤砾石混合介质水分蒸发特性研究

Study on water evaporation characteristics of red soil and stony medium

自然界土壤中常含有砾石,砾石使土壤水分运动特性发生变化。本文以红壤土为研究对象,开展土柱蒸发试验,设置4种砾石含量水平分别为0%(CK)、5%、10%、20%,分析不同砾石含量对土壤水分蒸发的影响。研究表明,不同砾石含量的土壤累积蒸发量表现为20%> 10%> 5%> CK。土柱累积蒸发量随砾石含量增大而增大;含有砾石的土柱蒸发量高于CK,原因是砾石与土壤结合中产生的大孔隙一定程度上促进了蒸发;采用3种不同模型拟合累积蒸发量和蒸发时间变化关系,结果表明Black蒸发模型拟合效果最好;随着蒸发时间的增长,土壤蒸发速率减弱。研究结果可为红壤区农田灌溉蓄水保墒等措施提供理论依据。

Gravel can be frequently found in soil profile,thus causing the variation of soil water movement. In this study,red soil was selected as test material,experiment was used for evaporation test in the indoor environment. Four amounts of gravel with contents of 0 %,5 %,10 % and 20 % were set,analyzed the effect of different gravel content on soil evaporation.Results showed that the cumulative evaporation of soil columns with different gravel content was 20 % > 10 % > 5 % > CK. The cumulative evaporation of the soil column increased with the increase in gravel content;the evaporation of the soil column containing gravel was higher than that of CK,because the large pores generated by the combination of gravel and soil increased evaporation;three different models were used to fit the relationship between cumulative evaporation and evaporation time,and it was found the Black evaporation model had the best fitting effect;as the evaporation time increased,the evaporation rate decreased. The research results could provide a basis for irrigation,water storage and moisture conservation measures in the red soil area.