Variation of runoff and sediment transport in the huai river – A case study

Abstract

Changes in runoff and sediment transport in the Middle Reach of the Huai River have been studied by using 58 years of field data. The runoff yield from the Huai River watershed mainly occurs in the sub-watershed of the river. At the downstream Wujiadu station, the difference in total drainage area between the south and the north branches of the river is 43% while the difference in runoff yield is only 9%. Sediment yield mainly comes from the headwaters in the northern region with the upstream of the Huai River playing a secondary role. The data demonstrate that there has been little change in long-term average annual runoff in the Middle Reach of the Huai River (MRHR) but there has been a dramatic decrease in average annual sediment transport. This decrease in sediment transport in the Huai River has resulted in changes in the geomorphology of the Middle Reach of the Huai River with time. Further analysis indicates that both the main channel and the floodplain of the estuary of Hongzehu Lake have a tendency towards the deposition of sediment. A trend and regression analysis is used in the compilation of field data, calculations, and analysis.