Changes in Different Classes of Precipitation and the Impacts on Sediment Yield in the Hekouzhen-Longmen Region of the Yellow River Basin, China

Abstract

The sediment yield of the Yellow River Basin has obviously decreased since the 1980s, and the impacts of precipitation on sediment yield changes have become increasingly important with the global climate change. The spatial and temporal variations in annual precipitation and different classes of precipitation in the Hekouzhen-Longmen region (HLR) in the middle reaches of the Yellow River Basin were investigated using data collected from 301 rainfall stations from 1966 to 2016. The impacts of precipitation variation on sediment yield were evaluated, and the hydrological modeling method was used to quantitatively assess the attribution of precipitation and other factors to sediment yield changes in the HLR. The results show that the annual precipitation and P10 increased from the northwest to the southeast of the HLR, suggesting it was drier in the northwest region of the HLR. P25 and P50 were mainly concentrated in the northwestern and southwestern parts of the HLR, reflecting that heavy rain was more likely to occur in these regions of the HLR. All of the annual precipitation and different classes of precipitation had no significant changing trends from 1966 to 2016, and the relationship between rainfall and sediment yield obviously changed in 2006. Compared with the average annual mean values from 1966 to 2016, both the annual precipitation and the different classes of precipitation were higher in the HLR during 2007–2016. The sediment yield decrease during 1990–1999 was mainly influenced by precipitation, while other factors were the main driving factor for the sediment yield decrease in the periods of 1980–1989, 2000–2009, and 2010–2016, and other factors have become the dominant driving factors of the sediment yield change in the HLR since 2000.

Jianghan plain, the locale of China’s Great Flood four thousand years ago

“…Only summer storms or early-spring ice melting over the Loess Plateau could generate floods that impacted the YRP. These floods generally carried enormous silty sediments onto the YRP, causing deposition and repeated channel avulsion e.g., (Chien 1961;Liu and Jiyang 1989;Kidder et al 2012;Dang et al 2018).…”

Prediction of Sediment Yield in the Middle Reaches of the Yellow River Basin Under Extreme Precipitation

“…The prediction of the sediment discharge is essential in the YRB, which directly affects the water resources management and planning, the allocation of sediment resources, and the application of water conservancy projects. Therefore, the causes of the changes in sediment yields have been the focus of previous studies on the YRB since the 1990s (Liu et al, 2014a;Shi and Wang, 2015;Xin et al, 2015;Dang et al, 2018;Zhao et al, 2018). Many studies have been carried out on the causes of sediment reduction, changes in precipitation and their effects on sediment discharge, and changes in extreme precipitation in the YRB (Miao et al, 2011;Wang et al, 2016;Gao and Wang, 2017;Zhang et al, 2018;Dang et al, 2019).…”