模拟降雨条件下烤烟植株对降雨再分配及产流的影响

Effects of flue-cured tobacco plants on rainfall redistribution and runoff generation with simulated rainfall

【目的】明确烤烟植株对降雨再分配及产流的影响,为坡耕地土壤侵蚀的防治及可持续利用提供理论依据。【方法】采用室内人工模拟降雨法,测定了40,80和120 mm/h降雨强度下烤烟旺长期的茎秆流、穿透雨、径流和渗漏,并进一步探讨了茎秆流和穿透雨与产流的关系。【结果】茎秆流量、穿透雨量和穿透雨率与降雨强度呈极显著正相关关系,而茎秆流率则与降雨强度呈极显著负相关关系;不同降雨强度下茎秆流率和穿透雨率分别为24.66%~28.79%和71.21%~75.34%。当降雨强度为40 mm/h时,茎秆流几乎不参与径流形成,当降雨强度为80和120 mm/h时,茎秆流再分配后形成径流和渗漏的比例分别为16.90%~20.54%和79.46%~83.10%;穿透雨再分配后形成径流和渗漏的比例分别为40.14%~66.19%和33.81%~59.86%。径流中来源于茎秆流和穿透雨部分的比例分别为0.82%~10.07%和89.93%~99.18%,而在渗漏中来源于茎秆流和穿透雨部分的比例分别为42.19%~44.21%和55.79%~57.81%。【结论】降雨经烤烟植株再分配后,茎秆流主要形成了渗漏,对地表径流的贡献相对较小;而穿透雨主要形成了径流和渗漏,是两者的主要来源。

【Objective】The effects of flue-cured tobacco plants on rainfall redistribution and runoff generation were investigated to provide basis for controlling soil erosion and sustainable use of slope land.【Method】Stemflow,throughfall,runoff and infiltration were measured indoor by rainfall simulator under different rainfall intensities of 40,80 and 120 mm/h.The relationships between stemflow,throughfall and runoff were also investigated.【Result】Stemflow,throughfall and throughfall ratio had significantly positive correlation with rainfall intensity,and there was remarkable and negative correlation between stemflow ratio and rainfall intensity.The throughfall and stemflow accounted for 24.66%-28.79%and 71.21%-75.34%of total precipitation under different rainfall intensities.The stemflow was partitioned into runoff and infiltration under rainfall intensities of 80 and 120 mm/h,which accounted for 16.90%-20.54%and 79.46%-83.10%of stemflow,respectively.The stemflow was barely changed into runoff under rainfall intensity of 40 mm/h.The ratios that throughfall was partitioned into runoff and infiltration were up to 40.14%-66.19%and 33.81%-59.86%,respectively.The ratios from stemflow and throughfall were 0.82%-10.07%and 89.93%-99.18%of runoff,and the ratios of stemflow and throughfall to infiltration were up to 42.19%-44.21%and 55.79%-57.81%,respectively.【Conclusion】Stemflow is mainly partitioned into infiltration after rainfall redistribution,and it contributes less to surface runoff.Runoff and infiltration mainly come from throughfall.