黄土区切沟对不同植被下土壤水分时空变异的影响

为掌握切沟对土壤水分时空变异的影响，选取水蚀风蚀交错区两个典型切沟样点为研究对象。采用时间序列分析和经典统计学方法，从土壤水分时间变化特征和空间分布格局两方面探讨。结果表明:距沟道不同距离下土壤储水量差异明显。300 cm处样点可作为测定尺度下土壤储水量平均值。土壤水分在垂直方向上的变异受植被特征影响，沟道影响较小。坡面土壤储水量的空间分布呈现不同的分布格局。坡顶风速大，土壤水分蒸发快，坡中处土壤储水量最高，为949.9 mm，距切沟越近土壤水分快速散失，坡下土壤水分接近4%，亏缺严重。杏树地土壤储水量远高于柠条地，柠条地土壤储水量分布较为单一。土壤蒸发、植被、沟道等因素使得坡面土壤水分分布更加复杂。

Effects of gullies on the spatiotemporal variability of soil-water under different vegetation types on the Loess Plateau

Gullies are pervasive topographic features on the Loess Plateau. We selected two typical gullies in the water-wind erosion region of the plateau to study the effect of gullies on the spatiotemporal variability of soil-water. The distribution and variation of soil-water storage were evaluated using time-series analysis and classical statistical methods. Soil-water storage varied with distance to the gully borders. The spatial average soil-water in the study sites was 300 cm from the border. soil-water in the vertical direction was mostly dependent on the vegetation, and the gullies had little impact. The spatial distribution of soil-water at a slope scale presented different patterns. Strong upland winds increased the evaporation of soil-water, which rapidly dissipated. Soil-water storage at mid-slope near the gullies was as high as 949.9 mm. The bottom of the slopes had soil-water deficits of 4%. Soil-water storage was much higher in an apricot orchard than in shrubland dominated by Caragana korshinskii Kom. Soil evaporation, vegetation type, and the gullies increased the complexity of the pattern of soil-water.