川中丘陵区高粱植株对降雨再分配的影响

The Effect of Sorghum Plants on Rainfall Redistribution Processes in Hilly area of Central Sichuan

为了明确成熟期高粱冠层截留分异能力,以川中丘陵区实际降雨强度为基础,以单穴每2株高粱为研究对象,采用水量平衡法对人工模拟条件下成熟期高粱截留量、茎秆流量和穿透雨量进行测定。结果表明,降雨经高粱冠层再分配后冠层截留率平均为12.6%,茎秆流率平均为30.8%,穿透雨率平均为56.7%。降雨强度与单位叶面积截留量、茎秆流量以及穿透雨量呈极显著线性正相关关系;叶面积与单位雨强截留量和茎秆流量呈极显著线性正相关,而与单位雨强穿透雨量呈极显著线性负相关关系。本研究条件下建立的截留后各组分与降雨强度和叶面积的拟合方程,仅使用降雨强度和叶面积2个参数就可以对成熟期高粱冠层截留后各组分进行较好地估测。在降雨集中时期,高粱冠层能体现出较强的降雨再分配作用,对该区域水土保持防治以及农业可持续发展具有重要意义。

The purpose of this study was to clarify the interception differentiation ability of the mature sorghum canopy, basing on the actual rainfall in purple hilly area of Sichuan, taking the sorghum which was in maturity and of single point for each of the two strains as the object of study, the water balance method was used to determinate the sorghum interception, stem flow and throughfall in the artificial simulated condition of the mature sorghum in this article. The results showed that after the redistribution of sorghum canopy, the canopy interception rate averaged 12.6%, the stem flow rate averaged 30. 8~, throughfall rate averaged 56.7 %. The rainfall had a significant positive linear relation with the interception, stem flow and throughfall of the per unit leaf area of sorghum. The sorghum leaf area had a significant positive linear relation with unit rainfall interception and stem flow, and a significant negative linear correlation with the rainfall of unit rainfall intensity interception. The fitting equation of each component after the canopy interception and rainfall intensity and leaf area established under this condition, could be used to estimate each component after the canopy interception of the sorghum canopy with only two parameters（rainfall intensity and leaf area）. In the concentrated rainfall period, sorghum canopy reflected stronger ability of retention differentiation, which had important significance to this district＇s soil and water conservation and the sustainable development of agriculture.