金沙江流域典型森林土壤水分入渗特征试验研究

Infiltration Characteristics of Different Forest Soils in Jingsha River Basin

对金沙江流域典型森林生态系统的土壤水文特征进行了研究。结果表明,研究区不同森林类型的土壤容重随着土层深度的增加而逐渐增大,土壤总孔隙度和毛管孔隙度随土层深度的增加而逐渐减小;土壤水分入渗受土壤容重的影响,随容重增加,稳渗率降低;不同森林类型土壤前120min平均入渗速率介于0.78-2.42mm/min之间,稳渗率介于0.10-0.53mm/min之间;无论是平均入渗率还是稳渗率均表现为：华山松林地〉滇杨林地〉圣诞树林地〉水冬瓜林地〉荒坡地;土壤入渗的渗润阶段发生在0-5min;渗漏阶段约发生在5-80min;渗透阶段发生在80min以后。采用Kostiakov模型拟合双环入渗法测得的入渗过程效果最佳,其次为Philip模型,而用Horton模型的拟合效果最差。

Soil hydrological characteristics were studied for different forest ecosystems in Jingsha River basin. Results showed that soil bulk density increased with the increase in soil depth,while total soil porosity and capillary porosity decreased.Average infiltration rates of different forest soil types ranged from 0.78to 2.42 mm/min and stable infiltration rates ranged from 0.10to 0.53mm/min.Average and stable infiltration rates presented such an order as：Pinus armandii forest landPobulus yunnenensis forest landAcacia bealbata forest landAluns cremastogyne forest landwasteland.The transient phase of infiltration occurred in the first 5min,the gradual phase occurred between 5and 80min,and the stable phase occurred after 80min. Kostiakov Model best fitted the infiltration process determined by double-ring method compared with Philip and Horton Model.