不同时间尺度下农田土壤风蚀可蚀性的变化

土壤风蚀可蚀性(简称土壤可蚀性)作为风蚀模型的必要输入参数之一,会随风蚀事件过程、耕作措施以及气象气候等因素发生显著变化,但目前对其变化趋势尚认识不足.本文采用野外观测、采样分析与空间换时间的方法,就次风蚀事件、风蚀月、风蚀季、多年4个时间尺度下坝上地区农田土壤可蚀性变化问题进行研究.结果 表明:严重风蚀事件过程中,地...

Changes of soil wind erodibility for farmland in different time scales

Soil wind erodibility （simplified as soil erodibility）， as one of the necessary input parameters in wind erosion models， changes significantly with the process of wind erosion events， tillage measurements， weather and climate factors， but its changing trend is still unclear until now. In this paper， by field observation， sampling analysis and space time exchange methods， the changes of farmland soil erodibility in Bashang district were studied under four time scales： wind erosion event， wind erosion month， wind erosion season and many years. The results showed that from the pre （stage） to post （stage） of the wind erosion event， the content of dry aggregate particles with diameter <0.85 mm in surface soil decreased significantly， and the threshold friction velocity increased significantly， and the sediment transporting rate decreased significantly， which all proved that the soil erodibility decreased significantly. In the time scales of wind erosion month， wind erosion season and many years， the soil erodibility for farmland， especially for ploughed farmland， showed a downward trend， and the longer the time scale， the larger the declining range of the soil erodibility. The strong wind erosion in Bashang district may be the main reason for the decline of farmland soil erodibility under different time scales. In order to reduce the damage of farmland wind erosion in Bashang district， reclamation of new farmland should be reduced as far as possible and ploughing should be avoided in the high incidence period of wind erosion events.