Abstract: A physical model of Chenjiawan-Haoxue reach in the Yangtse River is established,by which experiments are carried out for researching the influence of discharge on river pattern transformations at the lower reaches of water conservancy projects.The results show that deformation of the cross section and the plane of the river are in direct proportion to the amount of discharge,and different flow processes can lead to different formations of the river,so unsteady flow may engender the transformation of river p...