Location: Watershed Physical Processes ResearchTitle: A measurement method for rill and ephemeral gully erosion assessments
|Wells, Robert - Rob|
|MOMM, HENRIQUE - Middle Tennessee State University|
|BENNETT, SEAN - State University Of New York (SUNY)|
|GESCH, KARL - Iowa State University|
|CRUSE, RICHARD - Iowa State University|
Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/23/2015
Publication Date: 2/25/2016
Citation: Wells, R.R., Momm, H.G., Bennett, S.J., Gesch, K.R., Dabney, S.M., Cruse, R., Wilson, G.V. 2016. A measurement method for rill and ephemeral gully erosion assessments. Soil Science Society of America Journal. 80:203-214. doi:10.2136/sssaj2015.09.0820.
Interpretive Summary: This manuscript describes a technique to monitor soil erosion in ephemeral gullies. Twelve field sites were established in Iowa and monitored using photogrammetric methods. One person, using one camera, collected millimeter scale topographic information of 114 sites in 12 small watersheds in one day. The costs associated with equipment were less than $35 per site and the time investment of personnel was less than 30 minutes per site for site establishment, initial and secondary photo pair collection, photo pair processing, and time period comparison. Single-person photogrammetry of concentrated flow erosion can be conducted rapidly, cheaply, and with high spatial resolution (and low error), providing capture of discrete erosion processes responsible for soil loss and degradation (such as migrating headcuts, rill incision, bank failure, etc.).
Technical Abstract: When flowing water concentrates, the eroding force of the water may only be limited by the binding potential of the soil. Over time, concentrated flow paths may become permanent drainage pathways that often have negative impacts on crop yield and downstream sedimentation. Spatiotemporal topographic assessments of channel dimensions compliment hydraulic erosion estimates, providing process understanding, and model validation data. However, highly accurate and detailed assessments can be cost prohibitive. The character and timeliness of the assessment data, all too often, leave much to be desired and lead to inaccurate process theory and assumptions. A study site (12 small watersheds) was instrumented with survey monuments in central Iowa to quantify changes in concentrated flow paths. Within each watershed, multiple sites were monitored using photogrammetric techniques. This manuscript describes the study area, methods used to quantify concentrated flow path changes, and reports early results. Single-person photogrammetry of concentrated flow erosion can be conducted rapidly, cheaply, and with high spatial resolution (and low error), providing capture of discrete erosion processes responsible for soil loss and degradation (such as migrating headcuts, rill incision, bank failure, etc.).