监测土壤流失的标线法及其测定犁耕运移土壤的尝试

Marking String Method for Monitoring Soil Loss and Its Application on Testing Soil Redistribution by Tillage

介绍了监测土壤流失和堆积的一种新方法——标线法和在贵州普定喀斯特坡地开展试验研究测定犁耕侵蚀的结果。坡度3°、坡长24.2 m的石灰土旱坡地10次犁耕的试验结果表明:坡顶犁耕侵蚀速率0.67 cm/a,和实际情况相符;顺坡犁耕通量52.6 kg/(m.a),和其他研究者用小石子或137Cs、210Pbex核素示踪法测得的值基本一致。标线法具有简便易行、价值低廉和标线隐蔽性强、不易被发现破坏的特点,所测结果是可靠的。此法解决了侵蚀针或标桩法可能干扰径流和风流场的问题,且不妨碍犁耕,可广泛应用于流水侵蚀、风蚀和犁耕侵蚀的长期监测。标线法测得的是土壤点侵蚀和堆积量值,非常适用于侵蚀随坡长变化的研究。

The paper introduces a new method of monitoring soil loss and accumulation,named the marking string method and test results of tillage erosion carried out in the karst area of Puding County of Guizhou Province.The test results of dry-sloped land of lime soil with slope length of 24.2 m and gradient of 3°after 10 times' tillage show that: a) the tillage erosion rate at the head of land is 0.67 cm/a,which consists with the actual situation and;b) the tillage flux is 52.6 kg/(m·a),which is close to the values derived by the isotope tracing techniques with 137Cs or 210Pbex and the small stone tracing method used by other researchers.The marking string method has the advantages of low cost,simple and practicable operation and good seclusion.The test results are reliable too.This method has solved the problems of the marking pole or needle methods that might affect the runoff and wind flow fields.It not only does not hamper tillage,but also can be widely used to the long-term monitoring of water erosion,wind erosion and tillage erosion.The values of soil erosion and accumulation measured by the marking string method are greatly suitable for the study on erosion along with the variation of slope length.