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植被冠层对降雨的截留,改变了降雨在地表的分布,从而影响地表土壤侵蚀。因此植被冠层的水文作用一直是国内外研究的焦点。本研究对降雨在玉米行内不同位置的分布进行了测定,玉米行距60cm,在玉米行内布置5个观测位点,分别距玉米种植行0~12cm(A)、12~24cm(B)、24~36cm(C)、36~48cm(D)和48~60cm(E)。本研究穿透雨测定均在玉米生育期内进行,玉米株高为50~250cm,叶面积指数为0.4~4.0。结果表明行内不同位点的穿透雨存在空间异质性,2013年与2014年穿透雨测定日期内(每年各测定了7次),行内不同位点穿透雨变异系数范围分别为15.9%~45.4%和8.9%~42.2%,且在两行玉米中间的位置(24~36cm位置)穿透雨量较大。冠层下各位点穿透雨量与降雨量正相关,与叶面积指数、株高负相关(P<0.05)。随着作物生长,穿透雨在冠层下空间分布由均匀逐渐趋向于不均匀,具有趋向于向行中(24~36cm位置)汇集的趋势。该研究揭示了玉米对降雨的再分配作用特征,为农田水分有效利用和坡耕地土壤侵蚀防治提供理论依据。
Vegetation canopy interception of rainfall, changing the distribution of rainfall in the surface, thus affecting the surface soil erosion. Therefore, the hydrological role of vegetation canopy has always been the focus of research at home and abroad. In this study, the distribution of rainfall at different positions in maize lines was determined. The maize spacing was 60 cm, and five observation sites were arranged in maize lines, ranging from 0 to 12 cm (A), 12 to 24 cm (B) 36 cm (C), 36-48 cm (D) and 48-60 cm (E). The penetrating rain test in this study were conducted during the maize growth period. The plant height of maize was 50 ~ 250cm and the leaf area index was 0.4 ~ 4.0. The results showed that there were spatial heterogeneity of penetration rains at different sites in the row. During the determination of penetrating rain in 2013 and 2014 (measured 7 times each year), the coefficients of variation of penetration rains at different sites in the row were 15.9% ~ 45.4% and 8.9% ~ 42.2%, respectively, and the rainfall in the middle of the two rows of corn (24 ~ 36cm) is high. Rainfall per unit area under canopy was positively correlated with rainfall, negatively correlated with leaf area index and plant height (P <0.05). With the growth of crops, the penetrating rain tended to be inhomogeneous in the spatial distribution under the canopy, and tended to converge toward the rows (24-36 cm). The study revealed the redistribution characteristics of maize on rainfall and provided the theoretical basis for the effective utilization of farmland water and the prevention and control of soil erosion on sloping farmland.