Runoff frequency spectrum similarity calculation method for quantifying sponge effect and application thereof

The invention provides a runoff frequency spectrum similarity calculation method for quantitative sponge effect, which comprises the following steps: acquiring runoff daily value data of a long time sequence, and generating a runoff frequency spectrum matrix to represent runoff characteristics; generating a runoff spectrogram with an X matrix and a Y matrix which respectively represent a natural landform and a sponge city, and reflecting the difference of runoff characteristics; directly calculating the similarity of a matrix X and a matrix Y without calculating graph similarity, moving traffic with different cumulative frequencies in the matrix X and the matrix Y to a closest frequency position, aligning the cumulative frequencies of the matrix X and the matrix Y, and then calculating the similarity of the aligned matrix X and the matrix Y, calculating the similarity of the aligned matrix X and matrix Y according to each group of comparable difference degree and water volume weight, wherein the similarity re