STUDY AREA

2.1 General description of the study area

The Yellow River is the second longest river in China and is well known worldwide for its high sediment load; it has a total length of 5,464 km, and its basin drainage area amounts to 795,000 km2, as shown in Figure 1. The LYR, with a length of approximately 785.6 km, extends from Mengjin in Henan Province to Lijin in Shandong Province and has been divided into three reaches in terms of geomorphological features, namely, the braided reach, the transitional reach and the meandering reach (see Figure 1). Heavy soil erosion on the Loess Plateau has led to intense sedimentation in the LYR (Miao, Yang, Chen, & Gao, 2012), and the total depositional volume in the LYR was approximately 5.52×109m3 during the period from 1950 to 1999 based on observational data, of which 60% was deposited in the braided reach (Xia et al., 2010). The main effect of the heavy sedimentation in the LYR has been the obvious shrinkage of the main channel accompanied by a sharp decrease in the flood discharge capacity, which has resulted in the phenomenon of a secondary suspended river in certain reaches and a flood risk to the local residents and river management.