Objective In semi-arid regions, soil erosion and water loss pose a significant threat to the sustainable development of local agriculture and forestry. Rainfall is a major driving factor of soil erosion, and rainfall-induced soil erosion mainly depends on factors such as rainfall volume, rainfall duration, and rainfall intensity. Therefore, studying the comprehensive impacts of different rainfall types and various governance measures on slope soil erosion and water loss is of extremely important practical significance for implementing slope soil and water conservation practices.

Methods This study took the slope runoff observation field in Xiaoqingshan, Lanzhou as the research object, and set up runoff plots with two slope gradients (10° and 20°) and five different vegetation cover types: bare land, Solanum tuberosum, Linum usitatissimum, Lolium perenne and Caragana korshinskii. Rainfall data as well as runoff and sediment yield data from 2021 to 2024 were collected. The K-means clustering method was used to classify erosive rainfall, and an in-depth analysis was conducted on the characteristics and key influencing factors of slope runoff and sediment yield under different rainfall types.

Results 1) A total of 55 erosive rainfall events were recorded, accounting for 71.80% of the total rainfall amount. 2) Erosive rainfall was categorized into four types: Type Ⅰ (moderate frequency, low rainfall amount, high rainfall intensity, short rainfall duration); type Ⅱ (low frequency, moderate rainfall amount, low rainfall intensity, long rainfall duration); type Ⅲ (high frequency, moderate rainfall amount, moderate rainfall intensity, medium rainfall duration); and type Ⅳ (low frequency, high rainfall amount, high rainfall intensity, long rainfall duration). Type Ⅰ and type Ⅱ rainfall generated relatively small amounts of runoff and sediment yield. Type Ⅲ rainfall had a high occurrence frequency and yielded large amounts of runoff and sediment yield. Type Ⅳ rainfall, characterized by large rainfall amounts, high rainfall intensity and long duration, thus also yielded substantial runoff and sediment yield. 3) Under different erosive rainfall types, the runoff and sediment yield characteristics of each runoff plot varied significantly. Bare land had the highest amounts of runoff and sediment yields, while C. korshinskii-covered land, agricultural land (S. tuberosum and L. usitatissimum), and grassland had relatively lower yields. Additionally, the overall runoff and sediment yield on the 20° slope were higher than those on the 10° slope. 4) Rainfall amount and rainfall erosivity were the main factors influencing runoff and sediment yield, followed by average rainfall intensity and maximum 30-minute rainfall intensity (I₃₀), with rainfall duration having a relatively smaller impact.

Conclusions This study analyzes the impacts of various surface vegetation types and slope gradients on slope soil erosion and water loss under different types of erosive rainfall, providing data support for the rational planning of vegetation planting and land use. It also identifies rainfall amount and rainfall erosivity as the main factors influencing runoff and sediment yield, offering scientific guidance for rational allocation of resources in soil and water conservation practices.