Quantifying complex rock-soil architectures is fundamental to Critical Zone science. The karst Critical Zone, formed by carbonate dissolution, stands out as the most heterogeneous end-member. Yet, detailed characterization of karst system remains a major bottleneck, hindered by its inherent structural complexity and limited accessibility. This study integrated high-resolution geophysical surveys and hydrogeological borehole to quantify soil and epikarst distributions across a dolomite peak-cluster depression catchment. Results revealed that hillslope dominated the catchment (78.8% of total area), yet soils accumulated disproportionately in the depression, where 46.8% of total soil volume was concentrated. Mean soil thickness differed markedly between hillslope (Upslope: 0.17 ± 0.30 m) and depression (1.47 ± 1.30 m). Additionally, the area without soil cover reached 48.8% on hillslopes, compared to only 13% in the depression. The mean epikarst thickness was 6.6 m, and its spatial heterogeneity (CV: 64%) was smaller than that of the soil (CV: 105%). In contrast, the difference in epikarst thickness between hillslopes and depressions was less pronounced than that of soil thickness. Given the differentiation of soil-rock thicknesses, combined with fault and permeability, it was identified that hillslopes are predominantly characterized by a "thin soil (< 0.3 m) and thick epikarst" type, whereas depressions are dominated by a "thick soil (∼ 3.0 m) and epikarst" type. Accordingly, these findings imply a significant differentiation in the endowment of soil and water resources at the catchment scale, contributing to their management in the peak cluster-depression system of southwest China.
Zhang et al. (Mon,) studied this question.