Experience has shown that rain erosion-induced microtopographic features can be grouped into seven types: original or resistant clods, eroding clods, flow paths, prerills, rills, depressions and possibly basal cover. The features represent the erosion that has occurred during a period previous to observation. Features are recorded per 25 cm on lines of 12.5 m along the contour. An indicator of erosion intensity can be derived from the erosion feature distribution. The indicator is calculated as the percentage of eroded clods plus two times the percentage prerill and rill area. It shows significant to highly significant correlation with measured soil loss. This opens up the possibility of evaluating cropping systems and conservation practices for their protective effect against erosion. The erosion intensity can be compared for sites that represent the situation with and without conservation practices. The method can be used to monitor the development of erosion during a rain shower, a rainy season, or a series of years by recording the presence of the features at time intervals. Case studies in Colombia, Nepal, Tanzania and Thailand demonstrate the use of the microtopographic features for monitoring erosion density.
