The second step is data reduction. It aims to achieve an optimum balance between the volume of data and the density of sampling (Robinson, 1994, p.807). This helps in optimizing the cost of data collection. In optimal interpolation, incredibly detailed DEMS with high resolution and accuracy are obtained from high-density Airborne Laser Scanning data. However, since there is no scope for matching the acquisition frequency of data by terrain type during the Airborne Laser Scanning data collection process, some oversampling is typically unavoidable (Robinson, 1994, p.808). Consequently, the processing times and the data storage requirements become higher than usual. This calls for the strategies for dealing with greater volumes of terrain data to ensure accuracy. supposing efficiency is realized. Data reduction can result in an operationally sized and a more manageable terrain set of DEM generation data.&nbsp.Breakline extraction is another critical step. Breaklines are skeleton or structure lines such as valley lines or ridgelines. These are essential features of the terrain since they describe changes in the surface.