Assessing the Effects of Ecological Restoration Technology on Soil Erosion, Runoff and Sediment in Luoyugou Watershed of the Loess Plateau

The Loess Plateau is a densely populated, important ecological security frontier and a major grain-producing region in China. Conversely, it is highly susceptible to soil erosion. In response to soil erosion, a series of restoration technologies were launched, including afforestation, check dams, terraces and so on. Research on the restoration of the soil erosion is a key to regional sustainable development, and ecological protection and high-quality development in the Yellow River Basin. In this research, we analyzed the spatial and temporal patterns of soil erosion and compared the changes in runoff and sediment transportation in the whole watershed using spatial data, statistical data and GIS spatial analysis tools and RUSLE models. The main results include: (1) from 1990 to 2015, the soil erosion modulus in the Luoyugou Watershed dropped from 3706.2 t km–2 yr–1 to 2176.5 t km–2 yr–1, among which, the decline from 1990 to 1995 and 2000 to 2005 was the largest, with decrease of 827.8 t km–2 yr–1 and 480.7 t km–2 yr–1, respectively. (2) From 1988 to 2018, the M-K test of runoff and sediment transportation in the Luoyugou Watershed showed a downward trend. In the early period (1988–1998), the average annual runoff, annual sediment transportation, and sediment transportation per runoff were 2.23 million m3, 351000 t, and 182.2 kg m–3, respectively. In the later period (2008–2018), these values dropped to 852000 m3, 114000 t and 115.2 kg m–3, showing the decreases of 61.8%, 67.5% and 36.7%, respectively. (3) From 1988 to 2018, the runoff and sediment transportation showed a significant correlation with the annual rainfall in the Luoyugou Watershed. With the increase in rainfall, the runoff of Luoyugou increased rapidly in the early period (1988–1998) and the sediment transportation increased rapidly in the later period (2008–2018). The findings of this research provide reference for understanding the ecological and environmental effects of restoration technology and scientifically guiding ecological restoration practices.