A Simplified Close‐Range Photogrammetric Technique for Soil Erosion Assessment

Abstract

Surface reconstruction using digital pbotogrammetry offers a great advantage for soil erosion researcb. Tbe tecbnology can be cumbersome for field application because it relies on tbe accurate measurement of control points, often using a survey-grade instrument. Also, even tbougb digital pbotogrammetry bas been used in mucb soil erosion researcb, its sensitivity in detecting soil elevation cbanges bas rarely been assessed. Tbis study aimed at simplifying tbe digital pbotogrammetric procedure for soil erosion researcb and assessing tbe sensitivity of tbis tecbnology to detect soil erosion. To simplify tbe tecbnology, we propose to combine a pbotogrammetric procedure for control point generation in a first step, followed by a conventional pbotogrammetric digital elevation model (DEM) extraction procedure. Tbe performance of tbe metbod was assessed in tbe laboratory and tested in tbe field to digitize epbemeral gullies. In tbe accuracy test of pbotogrammetric survey step, we found tbat tbe maximum lengtb measurement error was 3.4 mm, wblle tbe maximum angular deviation from tbe vertical or borizontal axes was 0.93°. Tbe maximum error between control point coordinates generated by pbotogrammetry and tbose generated by a survey-grade total station was 26 mm on tbe borizontal axes and 10 mm on tbe vertical axis. We also found tbat tbe sensitivity of digital pbotogrammetry in detecting soil surface elevation cbanges was similar to tbat of a laser scanner wben tbe detection was performed on smootb soil surfaces and wbcn tbe standard deviation of tbe elevation cbanges was approximately tbree times the precision of tbe pbotogrammetric DEM.

Monitoring Riverbank Erosion in Mountain Catchments Using Terrestrial Laser Scanning

“…Since the 1990s, close-range photogrammetry [40] has been increasingly applied to investigate fluvial processes (e.g., [41]) and has recently become a consolidated technique for the monitoring of erosion processes, such as ephemeral gully geometry measurement, stream bank erosion, and gully headcut evolution [42]. This is mainly due to the flexibility of the photogrammetric data acquisition, the low budget required for both hardware and software components, and the high degree of automation that has been reached in the image-based surface reconstruction process [43].…”

Estimating machine impact on strip roads via close-range photogrammetry and soil parameters: a case study in central Italy

“…Although the use of close-range photogrammetry in mapping soil surface structure was demonstrated more than 20 years ago (Warner 1995), the advent of structure-from-motion (SfM) photogrammetry (James & Robson 2012) has generated an improvement in topographic methods, due to its better accessibility to a wider variety of users, low cost, and increased automatization of routines and workflow (Nadal-Romero et al 2015). The advantages introduced by SfM in geosciences have been demonstrated by James & Robson (2012), and the reconstruction of high-resolution surface models (Turner et al 2012) has opened new possibilities of application in geoscience analysis (Castillo et al 2015), forestry (Pierzchala et al 2014, Pierzchala et al 2016) and agriculture (Nouwakpo & Huang 2012).…”

The Role of Subsurface Hydrology in Soil Erosion and Channel Network Development on a Laboratory Hillslope

“…Nouwakpo and Huang (2012) that this technology performed as good as a laser scanner when quantifying substantial elevation changes such as those observed in ephemeral gully erosion. In this study, digital photogrammetry was used to incrementally quantify soil erosion and channel evolution during rainfall-runoff events.…”