Quantifying Ephemeral Gully Erosion with Photogrammetry Surveying

Abstract.

Soil erosion causes severe soil degradation and significantly contributes to total soil loss in agricultural fields. Sheet, rill and ephemeral gully erosion highly contributes to soil loss on farming lands. Majority of soil erosion models do not account for sedimentation occurring from both sheet-rill and ephemeral gully erosion, thus, they may lead to a difference between predicted and actual volumes of eroded soil. Therefore, it is needed to improve soil erosion models that account for both sheet-rill and ephemeral gully erosion. Lack of accurate and repetitive field measurements limit the understanding of soil erosion processes and computer model development. Moreover, accurate measurements are necessary to validate soil erosion models. To address these issues, low elevation photogrammetry based survey was used for assessing ephemeral gully erosion on three gullies in a field in northeast Kansas. Six repetitive measurements were obtained at different stages of 2016 growing season in each of the three gullies. After major storm events, total soil loss of each gully was calculated and topographic changes of the gully bed were observed. Areas which has soil deposition and soil erosion were identified.