Results - Response of Flood Events to Land Use and Climate Change - page 129

New DEM based on
observed point data

Original DEM Observed point data

30% observed
point data

30% point data
interpolation methods

RMSE

Drainage network

The best interpolation technique

Fig. 6.3 The processing of creating DEM based on different interpolation techniques

of surface derivatives. It should also be pointed out that no consideration is given
to how accurate the original DEM values are. When the interpolated values are
compared with the original data points, this provides a measure of error introduced
by the interpolation process, but says nothing about the absolute accuracy of the
elevation values compared with the true ground value.

6.2.2 Statistical Analysis

To quantify the results, first the RMSE was applied. The selection of an optimal set
of parameters to be used in deterministic and geostatistical methods required the
exploration of different combinations of values. Table 6.1 shows four statistical
analyses for each method: