Abstract:
Background The large-scale ecological construction of loess plateau has significantly reduced the amount of sediment transport in the Yellow River, but the amount of sediment transport of some typical tributaries is still high in the rainstorm condition. On July 26, 2017, heavy rainstorm hit the Wuding river, the peak discharge reached 4 480 m3/s, maximum sediment concentration was 837 kg/m3, which is the maximum recorded value since the construction of Baijiachuan hydrologic station.
Methods After rainstorm, we carried on an investigation on the erosion and sediment transport characteristics in typical watershed.
Results Under rainstorm, the soil erosion modulus of the small watershed is still very high, while due to the check dam system, the sediment delivery ratio is significantly reduced. In the background of the large-scale ecological governance, the main path of sediment transport in hilly gully region of Loess Plateau was terraced fields→sloping farmland→road→gully→check dam break→spoil in channel.
Conclusions In view of the sediment transport path, the author puts forward five countermeasures for the prevention and control of the Loess Plateau under the new situation:1) Improving the small watershed→a tributary→the mainstream of the Yellow River sediment transport channel, to ensure sediment transport fluently; 2) Keep promoting the Grain-for-Green Project and sloping to terrace project to strengthen the management of sloping farmland; 3) To strengthen the construction of rural road and control the capacity of slope runoff, prevention of road and gully erosion; 4) To enlargement the management of terraces; 5) To enhance the construction of project supervision, control construction projects spoil.