Evaluating of the spatial heterogeneity of soil loss tolerance and its effects on erosion risk in the carbonate areas of southern China

Abstract

Abstract. Soil loss tolerance (T value) is one of the criteria in determining the necessity of erosion control measures and ecological restoration strategy. However, the validity of this criterion in subtropical karst regions is strongly disputed. In this study, T value is calculated based on soil formation rate by using a digital distribution map of carbonate rock assemblage types. Results indicated a spatial heterogeneity and diversity in soil loss tolerance. Instead of only one criterion, a minimum of three criteria should be considered when investigating the carbonate areas of southern China because the "one region, one T value" concept may not be applicable to this region. T value is proportionate to the amount of argillaceous material, which determines the surface soil thickness of the formations in homogenous carbonate rock areas. Homogenous carbonate rock, carbonate rock intercalated with clastic rock areas and carbonate/clastic rock alternation areas have T values of 20, 50 and 100 t/(km 2 a), and they are extremely, severely and moderately sensitive to soil erosion. Karst rocky desertification (KRD) is defined as extreme soil erosion and reflects the risks of erosion. Thus, the relationship between T value and erosion risk is determined using KRD as a parameter. The existence of KRD land is unrelated to the T value, although this parameter indicates erosion sensitivity. Erosion risk is strongly dependent on the relationship between real soil loss (RL) and T value rather than on either erosion intensity or the T value itself. If RL > > T , then the erosion risk is high despite of a low RL. Conversely, if T > > RL, then the soil is safe although RL is high. Overall, these findings may clarify the heterogeneity of T value and its effect on erosion risk in a karst environment.

RETRACTED ARTICLE: Assessment on erosion risk based on GIS in typical Karst region of Southwest China

“…Y. Li et al (2017) evaluated the spatial heterogeneity of soil loss tolerance and its effects on erosion risk. These studies provide valuable data for the control of water and soil loss in karst areas.…”

Relationship among land surface temperature and LUCC, NDVI in typical karst area

“…6). In terms of the special geological environment of the study area, the karst area had a vulnerable calcium environment 27 . Barren and shallow soil leads to low vegetation coverage 28 , and the infiltration of surface water, water loss 29,30 , human disturbance and destruction cause serious soil erosion 31 , thus resulting in the exposure of bare rocks and rocky desertification 32,33 .…”

Estimates of Soil Renewal Rates: Applications for Anti-Erosion Arrangement of the Agricultural Landscape

“…The estimates of the rate of soil formation and of its most important indicator-the rate of formation of the humus horizon of soils-have been used to solve various scientific and practical problems: for the normalization of erosion losses of soil in the determination of T-values [42,43]; for correcting the necessary efficiency of erosion control measures [44]; for calculating the location of erosion control boundaries in agricultural landscape conditions [45]; for determining the durability of soil use in the presence of anthropogenically caused water and wind erosion [46]; and as an indicator of the regenerative capacity of an ecosystem [47].…”