黄河乌兰布和沙漠段凌汛期河岸动态变化及影响因素

Dynamics Change of River Bank and Factor Analysis in Ulan Buh Desert Section of the Yellow River

黄河凌汛期间河水的扩张与萎缩导致河岸带变化,影响沿岸植物的生态补水与沙漠沙入黄。研究以乌海水利枢纽至三盛公段冬凌夏汛期河岸为研究对象,分析了1989—2010年河岸带动态变化及其影响因素。结果表明:夏季4个时段,河岸呈现萎缩—扩张—扩张—萎缩动态变化;当左岸以向右摆动为主时,河岸呈右偏萎缩趋势;当左、右岸分别由两侧向外摆动时,河岸呈扩张趋势。冬季3个阶段黄河以左岸向左摆动为主,冰面呈萎缩—扩张—萎缩动态变化;且岸线萎缩时表现出向右偏移,扩张时表现出向左偏移。冬季冰封期河岸向同侧偏移变化较夏季更为明显,且左岸移动幅度显著大于右岸移动幅度。夏季汛期河岸变化与上游降水显著相关,冬季凌期河岸变化主要与下游温差和两岸地势相关。

During the ice flood of the Yellow River, expansion and contraction of the river leads to riparian changes, affects the ecological water of plants in the coastal and desert sand flow into the river. We analyzed the dynamic change of the River ebb and flow dynamic process and its influencing factors during 1989--2010 between Wuhai hydro-junction to Sanshenggong. The results show that the water level change trend is shrinking-expansion-expansion-contraction during the summer of four periods. On the left bank, the banks show a trend of shrinking and shifting to the right when it mainly shifts to the right. On the contrary, when the river bank shifts to the left on the left side, and the right to the right, river bank shows a trend of expansion. In winters of three periods, the left river bank shifts the left, and ice shows contraction-expansion-contraction trend. The river bank shows the right deviation trend when the river is shrinking. On the contrary, the river bank shows the left deviation trend when the river is expanding. Compared with flood period in summer, winter icy period on the left bank is given priority to sifting to the left, right bank is given priority to sifting to the right, and on the left bank shift extent is significantly greater than that of the right. Through the correlation analysis, change of river bank and upstream rainfall are significantly correlated in summer, but in winter, the water level change is related to downstream temperature difference and the left bank terrain of Ulan Buh Desert in the Yellow River.