模拟降雨条件下自然堆土流失特征研究

Research on the Soil Erosion Characteristics of Natural Pile under the Condition of Simulated Rainfall

探讨沈阳草甸土区不同植被类型与降雨强度对自然堆土产沙量、径流量的影响,为研究区水土流失防治与土地利用规划提供理论依据。采用两因素、三水平、三重复平行试验,利用人工降雨装置对3种植被类型(农田、荒地、林地)自然堆土进行3种降雨强度(0.64,1.05,1.52mm·min-1)的降雨试验,并对自然堆土泥沙侵蚀量、径流量进行对比分析。结果表明:在植被类型相同时,降雨强度与产沙量、径流量呈显著正相关(与产沙量相关系数分别为0.718,0.639,0.644;与径流量相关系数分别为0.676,0.682,0.628);在降雨强度相同时,不同植被类型堆土流失量差异明显,呈农田>荒地>林地,农田径流量最大,土壤侵蚀也最剧烈,相关分析表明产沙量与容重、黏粒含量具有显著正相关(与容重相关系数分别为0.593,0.724,0.692;与黏粒含量相关系数分别为0.592,0.729,0.704),产沙量与孔隙度、入渗率具有呈显著负相关(与孔隙度相关系数分别为-0.590,-0.715,-0.679;与入渗率相关系数分别为-0.582,-0.699,-0.658),说明影响土壤理化性质的植被类型是流失量差异的主要原因。因此,沈阳草甸土区自然堆土流失易受降雨强度与植被类型的影响,合理的规划利用土地能够有效控制水土流失。

This research adopts the two factors and three levels randomized block experiment,using artificial rainfall device to simulate three different intensity of rainfall(0.64, 1.05, 1.52mm·min-1) and analyse of surface runoff and sediment erosion. The results showed that the rainfall intensity was significantly positively related sediment yield and runoff under the same vegetation(the coefficients with sediment yield were 0.718, 0.639, 0.644; the coefficients with rainfall were 0.676,0.682,0.628), under the condition of same rainfall intensity, at the differences of pile soil loss different vegetation types were significant and followed the sequence: farmland > wasteland > forest land. Farmland runoff and soil erosion were the most intense. The correlation analysis showed that bulk density and clay content had a significant positive correlation with sediment yield(the coefficients with density were 0.593, 0.724 and 0.692. The coefficients with clay were 0.592, 0.729 and 0.704), porosity and infiltration rate had significant negative correlation with the sediment yield(the coefficients with porosity were-0.590,-0.715 and-0.679. The coefficients with infiltration were-0.582,-0.699 and-0.658). It revealed that vegetation type which leads to different soil physical and chemical properties is one of the important internal cause for sediment loss. Meadow soil in Shenyang area natural heap of soil erosion is vulnerable to the influence of rainfall intensity and vegetation types,therefore, reasonable planning on land utilization can effectively control soil erosion.