Relationship of benggang number, area, and hypsometric integral values at different landform developmental stages

In south China, benggang erosion causes intensive soil loss and land degradation. However, the mechanisms underlying its development remain unclear. In this study, the relationship between soil erosion, landform development, and benggang development in Jiangxi and Fujian provinces of China was investigated by using a soil erosion model and hypsometric integral (HI) values. Benggang number and area density are shown to increase first and then decrease with HI, with the highest benggang number density (0.27 benggang km−2) at a HI value between 0.18 and 0.20, the largest benggang area density (0.0016 km2 km−2) at a HI value between 0.14 and 0.16, and 78.66% of benggang in the stage of HI > 0.16. The current regional benggang erosion shows an aggravating trend, with a denudation rate of 0.04–5.7 mm yr−1，reducing HI by 1 × 10−7–1.03 × 10−4 per year in each watershed. The active period of regional benggang varies from 2,029 to 53,999 years with an average of 26,371 years. The landform development shows a close relationship with benggang evolution and can be divided into four zones: no benggang, historical benggang, current benggang, and potential benggang. Current benggang dominated (70.52%) in Jiangxi Province, while potential benggang (68.60%) in Fujian Province, suggesting a fall‐rise pattern for this erosion in the future. This study contributes to the understanding of the regional benggang development and the adoption of corresponding measures to control it.