芦苇阻水河道内众多滩地和改道段生长着芦苇,致使水道河床糙率增大,行洪水位全面抬高,严重削弱了行洪能力,给安全度汛带来了很大威胁。例如,淮河入江水道的三河段,由于芦苇茂密,1991年汛期,三河闸下泄流量为3000m~3/s 时,金湖站水位抬高到10.33m,相当于设计5000m~3/s 的水位,致使入江水道大堤堤脚普遍窨潮渗水,堤上三处出现裂缝,13座涵闸岌岌可危,被迫打坎封闭。近几年来,国家虽然投入 Many reeds and diversions in reeds blocked the growth of reeds, resulting in the river channel roughness increased, the flood plain elevation, seriously weakened the flood capacity, flood safety has brought a great threat. For example, the water level of Jinhu Station rises to 10.33m due to dense reeds in flood season in 1991 and flood discharge of Sanhe River at flood season of 3000m ~ 3 / s, which is equivalent to the designed water level of 5000m ~ 3 / s, As a result, the levees of the levees of the inlets in the river were generally seeped into water infiltration. There were cracks in the three embankments, and 13 culverts were in danger and were forced to close the embankment. In recent years, although the country invested