Effects of LPI Interpolation Parameters on Building of Debris Flow Gully DEM

Yue Yanli;Luo Mingliang;Zhang Bin;Mu Kai;Land and Resource College, China West Normal University;

LPI interpolation parameters;;debris flow gully;;Xiejiadian landslide mass;;DEM;;interpolation accuracy

This study aims to use local polynomial interpolation(LPI) to build DEM model of debris flow gullywhich is caused by earthquake, analyze the effect of interpolation parameters on interpolation precision, andextract the optimum interpolation parameters. The debris flow gully of Xiejiadian landslide mass inYinchanggou, Pengzhou City was used as an example, mean error(ME), root mean square error(RMSE),maximum positive error and negative error(MPE and MNE) and the percentage of positive errors and negativeerrors(PPE and PNE) were used as accuracy evaluation indexes of the interpolated DEM, the accuracy ofDEMs that interpolated was analyzed by different powers(P), kernel functions [K(x)], bandwidth(H) and sectortypes, and the optimum interpolation parameters were contrastively analyzed and extracted. The results showedthat with the other parameters being defaulted, the interpolation accuracy was the highest when interpolatedwith P=2; the imitative accuracy was the best when interpolation K(x) was Exponential; the interpolationaccuracy of four different sector types in LPI interpolation process had little difference; the optimum choice ofH value was 2 in interpolation; the positive errors and negative errors of all experimental results with variousinterpolation parameters in LPI were approximately half-and-half distributed. The result of DEM model builtby LPI met the accuracy of large scale DEM in Xiejiadian debris flow gully, the parameters of P, K(x) and Hhad great effect on interpolation accuracy, but sector type had little effect on interpolation result, theoptimization of interpolation parameters could contribute to the DEM modeling in debris flow gully terrain.