Slope multi-flow-direction overflow analysis method considering surface accumulated water depth change

The invention relates to a slope multi-flow-direction overflow analysis method considering surface accumulated water depth change. The method comprises the steps of determining the surface accumulatedwater depth, determining the slope dynamic confluence path, determining the slope multi-flow-direction water quantity distribution weight and determining the slope multi-flow-direction overflow waterquantity. The method aims to solve the problem of small surface fluctuation in plain bumpy areas, large ponding area and fast change, achieves accurate depiction of dynamic change of the surface ponding depth and conversion of the water inflow and outflow relationship between the surface ponding depth and peripheral units, solves the problem of application distortion of a conventional digital elevation model, finely simulates the slope multi-flow-direction flooding process, and effectively improves simulation of the surface runoff production process of the plain low-lying area. The method isoriented to plain bumpy area hydrological simulation, and related results can provide basic support for plain bumpy area hydrological model construction and application.