Assessment of crusting effects on interrill erosion by laser scanning

Yaxian Hu; Wolfgang Fister; Yao He; Nikolaus J Kuhn

doi:10.7717/peerj.8487

Assessment of crusting effects on interrill erosion by laser scanning

PeerJ. 2020 Jan 31:8:e8487. doi: 10.7717/peerj.8487. eCollection 2020.

Authors

Yaxian Hu^{1

2}, Wolfgang Fister², Yao He¹, Nikolaus J Kuhn²

Affiliations

¹ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi, China.
² Physical Geography and Environmental Change, Department of Environmental Sciences, University of Basel, Basel, Switzerland.

Abstract

Background: Crust formation affects soil erosion by raindrop impacted flow through changing particle size and cohesion between particles on the soil surface, as well as surface microtopography. Therefore, changes in soil microtopography can, in theory, be employed as a proxy to reflect the complex and dynamic interactions between crust formation and erosion caused by raindrop-impacted flow. However, it is unclear whether minor variations of soil microtopography can actually be detected with tools mapping the crust surface, often leaving the interpretation of interrill runoff and erosion dynamics qualitative or even speculative.

Methods: In this study, we used a laser scanner to measure the changes of the microtopography of two soils placed under simulated rainfall in experimental flumes and crusting at different rates. The two soils were of the same texture, but under different land management, and thus organic matter content and aggregate stability. To limit the amount of scanning and data analysis in this exploratory study, two transects and four subplots on each experimental flume were scanned with a laser in one-millimeter interval before and after rainfall simulations.

Results: While both soils experienced a flattening, they displayed different temporal patterns of crust development and associated erosional responses. The laser scanning data also allowed to distinguish the different rates of developments of surface features for replicates with extreme erosional responses. The use of the laser data improved the understanding of crusting effects on soil erosional responses, illustrating that even limited laser scanning provides essential information for quantitatively exploring interrill erosion processes.

Keywords: Crusting; Inter-replicate variability; Laser scanning; Microtopography; Temporal variation.

Grants and funding

This work was supported by the Natural Science Foundation of China (No. 41701318), the National Key Research and Development Project of China (2018YFC0507001), Innovative Research Program of the Ministry of Education, China (A315021608), and the University of Basel. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.