Based on remote sensing synthetic analysis

the distribution regularities of strip collapsing and arc collapsing along middle-lower Yangtze River are explored. The mechanisms of the two types of bank collapsing

especially the plane eddy mechanism of arc collapsing are discussed. It is considered that the occurrence of arc collapsing is resulted from the forming of whirlpools near some special shores. Using the eddy theory of hydrodynamics

the principles and the method by means of critical negative pressure to evaluate the occurrence of arc collapsing are suggested.