Abstract
Rainwater-induced soil erosion occurring in the forest is a special phenomenon of soil erosion in many red soil areas. Detection of such soil erosion is essential for developing land management to reduce soil loss in areas including southern China and other red soil regions of the world. Remotely sensed canopy cover is often used to determine the potential of soil erosion over a large spatial scale, which, however, becomes less useful in forest areas. This study proposes a new remote sensing method to detect soil erosion under forest canopy and presents a case study in a forest area in southern China. Five factors that are closely related to soil erosion in forest were used as discriminators to develop the model. These factors include fractional vegetation coverage, nitrogen reflectance index, yellow leaf index, bare soil index and slope. They quantitatively represent vegetation density, vegetation health status, soil exposure intensity and terrain steepness that are considered relevant to forest soil erosion. These five factors can all be derived from remote sensing imagery based on related thematic indices or algorithms. The five factors were integrated to create the soil erosion under forest model (SEUFM) through Principal Components Analysis (PCA) or a multiplication method. The case study in the forest area in Changting County of southern China with a Landsat 8 image shows that the first principal component-based SEUFM achieves an overall accuracy close to 90%, while the multiplication-based model reaches 81%. The detected locations of soil erosion in forest provide the target areas to be managed from further soil loss. The proposed method provides a tool to understand more about soil erosion in forested areas where soil erosion is usually not considered an issue. Therefore, the method is useful for soil conservation in forest.
Highlights
Soil erosion is a serious problem common in many areas of the world
It shows that FVClinear has higher accuracy than FVCquadratic as its scatters spread closer to 1:1 line than those of FVCquadratic and its RMSE (4.63) is much lower than that of FVCquadratic (18.42)
The croplands were masked out from the thematic images since this study focuses on forest areas
Summary
Soil erosion is a serious problem common in many areas of the world. It causes severe land degradation and affects soil fertility, agriculture productivity, water quality and regional ecosystems and environments [1]. Liao et al [6] investigated soil erosion in forests based on 9-year monitoring data of seven sub-catchments in Zhejiang Province, southern China and summarized the processes of soil erosion under forest canopy. Lei [3] studied soil loss in forests in a granite region of Xingguo County, Jiangxi Province and provided suggestions to control soil erosion in the forest. He et al [2] discussed the status and causes of soil erosion in Pinus massoniana woodlands in hilly red soil regions of southern China and found that the lack of vegetation mulch under trees and human disturbance were the main factors causing the erosion. Zhang et al [5] assessed soil erosion from remote sensing data in rehabilitated high-density forests of Hetian, a typical red soil region in southern China and found that the eroded areas were primarily distributed in locations with elevations between 300 to 500 m
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
