摘要
以春季风蚀活动高发期为特定研究时段 ,采用地面埋设容器的“陷阱诱捕”法 ,对秋收后翻耕的裸露沙质农田春播前的土壤风蚀量动态进行了定位观测 ,同时对影响土壤风蚀的关键因子表土层紧实度和含水量以及风速动态也进行了同步观测。主要研究结果是 :(1)观测期内 ,平均土壤日风蚀量为 2 4 1.2 0 kg/ hm2 ,土壤日有机碳和氮素损失量平均分别为 1.5 2 ,0 .15 kg/ hm2 。 (2 )土壤风蚀过程以细微土粒的跃移和悬移运动为主 ,损失掉的主要是表层土壤中的细砂 (粒径 0 .1～ 0 .0 5 mm)、粉粒 (粒径 0 .0 5～ 0 .0 0 2 mm)和粘粒 (粒径 <0 .0 0 2 mm)等富含营养元素的细微颗粒 ,分别占风蚀沉积物的 4 6 .0 1% ,2 1.0 3%和 2 1.74 %。这表明土壤风蚀导致了农田的粗化。 (3)相关分析表明 ,土壤风蚀量与表土层含水量呈一定的负相关 ;土壤风蚀量与表土层紧实度呈微弱的负相关。然而 ,土壤日风蚀沉积量与日平均风速呈高度正相关 ;同样 ,土壤日风蚀沉积量与日可蚀风持续时数亦呈高度正相关。利用它们之间的回归关系式 ,可以定量地预测。
The field experiment was conducted in a bare sandy farmland during erosion prone spring to study the dynamics of daily wind erosion sediment and to develop a predictive equation relating daily wind erosion sediment to daily average wind velocity and daily duration of erosion induced wind (≥5m/s at 10 m height) event. The main results were as follows:(1)During the 39 day observation period between March 22 and April 29, daily wind erosion sediment ranged from 1.32 g/m 2 to 130.33 g/m 2, with an average of 24.12 g/m 2, equivalent to 241.20 kg/hm 2. Total amount of wind erosion sediment over the entire observation period was 940.68 g/m 2, equivalent to 9 406.80 kg/hm 2. (2)In terms of the observed data of daily wind erosion sediment and the contents of soil organic carbon and nitrogen in the sedimentary material samples, the calculated daily average losses of soil organic carbon and nitrogen through wind erosion were 1.52 kg/hm 2 and 0.15 kg/hm 2, respectively. Total amount of soil organic carbon and nitrogen loss over the entire observation period was 59.28 kg/hm 2 and 5.85 kg/hm 2, respectively. (3)The particle size distribution analysis of the sedimentary soil material revealed that the proportion of coarse sand (diameter:0.5～0.1mm), fine sand (diameter: 0.1～0.05mm), silt(diameter: 0.05～ 0.002 mm) and clay (diameter< 0.002 mm) was 11.22%, 46.01%, 21.03% and 21.74%, indicating that more nutrient rich micro soil particles were blown away by wind from the bare sandy farmland. (4)Daily soil erosion sediment was found to significantly and positively correlate with daily average wind velocity; Similarly, we found a significant positive relationship between daily wind erosion sediment and daily duration of erosion induced wind event.
出处
《水土保持学报》
CSCD
北大核心
2002年第A01期29-32,79,共5页
Journal of Soil and Water Conservation
基金
中国科学院"百人计划"项目
中国科学院寒区旱区环境与工程研究所知识创新工程项目 (2 10 0 97)
国家 973项目"沙漠化的生物过程与植被恢复重建机理"(G2 0 0 0 0 4870 4)资助
关键词
风蚀沉积量
风速
可蚀风持续时数
土表紧实度
沙质农田
科尔沁沙地
wind erosion sediment
wind velocity
erosion induced wind duration
soil hardness
sandy farmland
Korqin sandy land
