Application of historical and recent aerial imagery in monitoring water erosion occurrences in Czech highlands

Abstract

This study is focused on the historical evolution of a heavily eroded field with discontinuous grass cover on a major thalweg (ephemeral gully). Tens of parcels originally formed a protective pattern in the study area, and the thalweg was permanently covered with grass. During the period of collectivization, the field structure had been unified into a compact 34 ha parcel, which resulted in the formation of ephemeral gullies after every heavy rainfall event. Historical and recent aerial photographs were used to analyze the erosion occurrences, vegetation degradation connected with the erosion processes, and the land-use pattern. The visual erosion pattern assessment has indicated that in this field, rills and other erosion manifestations have repeatedly developed in the same locations in different time periods. The soil erosion hazard was also modelled by the new Czech erosion model Atlas EROZE. A comparison between the modelling results and the assessment of real visual data shows that areas at risk can be identified by both these methods. In addition, the land-use pattern was modelled using two different scenarios. The results suggest that soil erosion can be significantly reduced by segmentation of the field into smaller plots.