Prediction of the Tendency of Variation in Water and Sediment Runoff in the Kuyehe River

Zhang Shengli (Institute of Hydraulic Research, YRCC)

coarse sediment-laden river development of coal mining field harnessment of river basin water and sediment variation tendency Kuyehe River

Kuyehe River is one of the heavily coarse sediment-laden tributary of the Yellow River between Hek-ouzhen and Longmen. Severe soil loss is observed in the river basin where the Shenfu-Dongsheng opencast coal mining is under development and human activities are intensive. Tendency of the variation of water and sediment runoff causes much concern. According to an estimate, the wasted earthy and stony disposed during the first and second phases of project construction in this area amounts to 630 million tons. It is predicted that average sediment output from the basin may be 11. 3~11. 5 million tons annually from 1987 to 2000. In the planning of bring the soil erosion under control, it is estimated that water and sediment runoff may be reduced by 37. 8% and 37. 1% respectively prior to the year 2000. It is known from the analysis, the sedi-ment scoured might increase the sediment load by 13. 3%~36. 5% during a flood event once a dam-break were to take place. River channel sedimentation may aggravate flood control difficulties, and the sediment may centrally eject into the Yellow River. Flood sedimentation may dramatically increase during a rainy year, while water amount may further reduce and even a water resources crisis may emerge during a dry year.