The potential for soil erosion control associated with socio-economic development in the hilly red soil region, southern China

Abstract

Socio-economic development greatly affects soil erosion and the implementation of soil and water conservation (SWC) techniques. Here, we proposed a new index, the potential for soil erosion control (P), and investigated socio-economic determinants for ΔP using Partial Least Squares Regression (PLSR) during 2005–2015 in the hilly red soil region of southern China. P was defined as 1 minus the ratio of the minimum possible soil erosion to the actual soil erosion, which can reflect the gap between the actual soil erosion and the minimum possible soil erosion. According to P, it would be impossible for 100% of the study area to experience a soil erosion rate of less than the tolerable soil erosion rate due to the biophysical limits, which would avoid waste caused by excessive governance. The two PLSR models were statistically significant and the selected socio-economic factors can account for 37% and 28% of the variations in the positive and negative |ΔP|, respectively. Base on the PLSR model for the positive |ΔP|, the VIP value of urban population growth (URBPOP_GR) and rural population growth (RURPOP_GR) were −1.31 and 1.71, respectively, demonstrating that URBPOP_GR suppressed erosion while RURPOP_GR increased erosion. Government investment in afforestation can significantly reduce soil erosion (VIP greater than 1). Increasing grain output per km2 would reduce the positive |ΔP|, indicating that advanced farming practices can balance production and soil protection. These results emphasized that policies for soil erosion control should be developed from not only a simplistic technological perspective but also a social-ecological perspective, and economic growth will control soil erosion effectively if it can provide more positive feedback to rural areas.