Reprint Summary

     An easy to use, field based procedure for estimating soil erosion caused by soil disturbances in mountainous areas is discussed in detail. Measurements are taken two or more times a season using an inexpensive erosion bridge, a four foot aluminum masonry level placed on two fixed support pins. A sampling unit consits of two erosion bridges placed end-to-end; the distance to the soil surface is measured at 10 fixed points along each bridge. An unbiased estimator of the surface change is obtained by an initial random selection of both sampling units and erosion bridge orientation. These data are used to calculate the average change in the soil surface elevation. Examples show how to use t-statistics to calculate a confidence interval for the mean, compare a measured mean with a standard value, or compare the values of two measured means. Resultinginformation can be used to evaluate cause and effect relationships between management practices and soil erosion as well as soil erosion effects on vegetative productivity and sediment production.