Research Progress and Outlook on Soil Erosion and Leakage in Karst Regions of Southwest China

Abstract

As the world's largest and most fully developed karst distribution zone, the karst regions of Southwest China possess an extremely fragile ecological environment. Their unique surface-subsurface dual three-dimensional hydrogeological structure results in a distinctive feature of concurrent surface runoff and subsurface seepage, posing a major constraint to regional ecological governance and sustainable socioeconomic development. This paper systematically reviews research progress on soil erosion/leakage in the Southwest Karst region, focusing on the core characteristics of the regional natural environment (poor soil, karst development, concentrated rainfall) and human activities (overcultivation, vegetation destruction, engineering disturbances). It summarizes the primary pathways of soil erosion (surface slope runoff migration, subsurface fissure/pipeline transport) , research methodologies (traditional runoff plot observation, erosion line method, ground-penetrating radar, and application of new techniques like radionuclide tracers), and fundamental findings (contribution quantification, driving factors, relationships with rock desertification and nutrient loss). It also categorizes control technologies including engineering, agricultural, biological measures, and agroforestry models. Building on this foundation, it delves into critical challenges in current research: Controversy persists over primary pathways for subsurface leakage - Multiscale coupling mechanisms of driving factors remain unclear - Proportions of surface-subsurface loss lack consensus - Mechanisms linking soil erosion/leakage to nutrient cycling are understudied Finally, future research directions are proposed, including clarifying leakage pathways, quantifying coupling relationships between drivers, standardizing proportion estimation criteria, and deepening understanding of nutrient impact mechanisms. These findings provide scientific references for precise soil erosion control, karst desertification management, and ecosystem restoration in the karst regions of Southwest China.