Response of runoff and soil erosion to erosive rainstorm events and vegetation restoration on abandoned slope farmland in the Loess Plateau region, China

It has been widely known that vegetation restoration plays a vital importance in controlling surface runoff and soil erosion. The most of soil erosion were caused by erosive rainstorm events. Yet, the response of surface runoff and soil erosion to erosive rainstorm events and vegetation types has not been fully understood. In this study, we monitored the vegetation, rainfall, runoff and soil erosion on ten runoff plots under field conditions from 2015 to 2019 and examined the impact of erosive rainstorm events on runoff and soil erosion among different vegetation types (Artemisia scoparia → Stipa bungeana → Lespedeza davurica (Asc → Sb → Ld), Stipa bungeana → Artemisia gmelinii (Sb → Agm), Bothriochloa ischaemum (Bi), Artemisia gmelinii + Stipa bungeana (Agm + Sb), Artemisia gmelinii + Stipa grandis (Agm + Sg), Sophora viciifolia (Sv), Artemisia gmelinii + Artemisia giraldii (Agm + Agi)) and bare land on abandoned land slopes. The results showed that vegetation restoration could decrease 68.0% to 97.4% of runoff and 98.0% to 99.9% of soil erosion compared to the bare land and there were no significant difference of surface runoff and soil loss among different vegetation types under the 11 erosive rainstorm events. The average soil loss of erosive rainstorm events among vegetation types could be 2.1 to 15.6 times as those of ordinary erosive rainfall events. The erosive rainstorm events caused a significant variance of surface runoff and soil erosion because of variant antecedent soil moisture and rainfall intensity. In practice, the natural vegetation restoration should be recommended in semi-arid environment and, the erosive rainstorm events should be paid enough attention in causing intense soil erosion in the rainy reasons.