Abstract
Soil erodibility K factor is an important parameter for evaluating soil erosion vulnerability and is required for soil erosion prediction models. It is also necessary for soil and water conservation management. In this study, we investigated the spatial variability characteristics of soil erodibility K factor in a watershed (Changyan watershed with an area of 8.59 km2) of Enshi, southwest of Hubei, China, and evaluated its influencing factors. The soil K values were determined by the EPIC model using the soil survey data across the watershed. Spatial K value prediction was conducted by regression-kriging using geographic data. We also assessed the effects of soil type, land use, and topography on the K value variations. The results showed that soil erodibility K values varied between 0.039–0.052 t·hm2·h/(hm2·MJ·mm) in the watershed with a block-like structure of spatial distribution. The soil erodibility, soil texture, and organic matter content all showed positive spatial autocorrelation. The spatial variability of the K value was related to soil type, land use, and topography. The calcareous soil had the greatest K value on average, followed by the paddy soil, the yellow-brown soil (an alfisol), the purple soil (an inceptisol), and the fluvo-aquic soil (an entisol). The soil K factor showed a negative correlation with the sand content but was positively related to soil silt and clay contents. Forest soils had a greater ability to resist to erosion compared to the cultivated soils. The soil K values increased with increasing slope and showed a decreasing trend with increasing altitude.
Highlights
Erosion can directly or indirectly cause soil quality decline, land degradation, soil resource loss of arable land and even result in serious natural disasters [1,2,3]
The mechanical composition of soils in the Changyan watershed was dominated by silt and clay particles (63.94~85.21%), and the organic matter content was generally increased with decreased altitude
The soil erodibility, mechanical composition, and organic matter content all showed positive spatial autocorrelation in which clay content was the most significant followed by the sand content, the organic matter content, the K value, and the silt content
Summary
Erosion can directly or indirectly cause soil quality decline, land degradation, soil resource loss of arable land and even result in serious natural disasters [1,2,3]. Plenty of researchers have investigated the effects of soil and environmental properties on erodibility, compared the performance of different soil K factor estimation methods, and evaluated spatial variability characteristics and influencing factors of the. Martínez-Murillo et al (2020) verified the validity of the RUSLE K factor by the stability of agglomerates in the Mediterranean mountains of southern Spain [16]. These methods did not consider the spatial autocorrelation of soil erodibility K values and influencing factors in small watersheds, resulting in the loss of information on the degree of spatial aggregation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
