Effects of Extreme Precipitation on Runoff and Sediment Yield in the Middle Reaches of the Yellow River

Abstract

Understanding the link between extreme precipitation and changes in runoff and sediment yield is of great significance for regional flood disaster response and soil and water conservation decision-making. This study investigated the spatial and temporal distribution of extreme precipitation (characterized by 10 extreme precipitation indices recommended by the Expert Team on Climate Change Detection and Indices) in the Toudaoguai–Longmen section of the middle Yellow River from 1960 to 2021 and quantified the effects of extreme precipitation on runoff and sediment yield based on the method of partial least squares regression (PLSR). The extreme precipitation index showed an obvious upward trend in the last 20 years, with the increases in the central and northern regions (upstream) being stronger than the increase in the southern region (downstream). However, the runoff and sediment yield decreased significantly due to the implementation of large-scale soil and water conservation measures on the Loess Plateau, with average rates of 94.7 million m3/a and 13.3 million t/a during 1960–2021, respectively. The change points of runoff and sediment yield change occurred in 1979. Compared with those in the period from 1960 to 1979, the reductions in runoff and sediment yield in the years 1980–2021 were 52.7% and 70.6%, respectively. Moreover, extreme precipitation contributed 35.3% and 6.2% to the reduction in runoff in the 1980–1999 and 2000–2021 periods, respectively, and contributed 84.3% and 40.0% to the reduction in sediment yield, respectively. It indicated that other factors (such as large-scale soil and water conservation construction) played main roles in the decrease in runoff and sediment yield in the study area in recent 20 years.

Future Joint Probability Characteristics of Extreme Precipitation in the Yellow River Basin

“…To place these findings in context, it is important to compare them with previous research in this area. Previous studies have also examined the relationship between extreme precipitation and runoff in various regions [37,38]. However, our research uniquely focused on the Yellow River Basin, where extreme precipitation events have significant implications for flood risk.…”

CMIP6 Simulation-Based Daily Surface Air Temperature and Precipitation Projections over the Qinghai-Tibetan Plateau in the 21st Century

“…Notably, IDR exhibits the highest change rate among the 10 sub-regions in the vast majority of scenarios and periods, with growth rates reaching 22.9 to 41.2% in the distant future. The significant increase in the annual maximum five-day precipitation, as an indicator of extreme precipitation, implies an elevated risk of hydrogeological disasters, such as floods, landslides, and debris flow [85][86][87]. Most areas in IDR are above 4000 m, given its higher elevation (Figure 1).…”