Scenario analysis of high and steep cutting slopes protection in the loess hilly region: A case study of the Yangjuangou catchment in Yan'an, China.

• The elasticity index is adopted to tradeoff the benefits and ecological effects of land consolidation. • Soil erosion of slopes with vegetation is tolerable under climate change. • Slopes below 63° are stable in 6 slope scenarios. • The slope of 53° with Caragana microphylla is the optimal combination scheme. Soil erosion and slope instability restrict the cutting slopes, especially the high and steep slopes of a construction site. It is difficult for present research of observation experiments and investigation to deal with these problems under climate change. Focusing on gully land consolidation in the loess plateau of China, this paper put forward a technical procedure to explore the optimal combination scheme of slope-cutting and vegetation-planting in future climate change. The technical procedure includes scenarios design, model calculation, and scheme optimization. This paper selected a back catchment in Yangjuangou catchment of Yan'an City as a case study and designed 54 combined scenarios consisting of 6 slopes, 3 types of vegetation (including bare land), and 3 climate scenarios. The soil erosion and slope stability under different scenarios were quantified using FLAC/Slope software and Water Erosion Prediction Project (WEPP) model. This paper innovatively designed elasticity indicators to trade off the increase of the flat land area formed by land consolidation and the resulting reduction in slope stability and increase in soil erosion. It is found that the slope of 53° with Caragana microphylla could be the optimal combination scheme considering flat land creating and the safety of slopes. The technical procedure and the resulting parameters could support gully land consolidation in related areas and be referenced by other construction projects. [ABSTRACT FROM AUTHOR]