Generation of High Spatial Resolution Terrestrial Surface from Low Spatial Resolution Elevation Contour Maps via Hierarchical Computation of Median Elevation Regions

We proposed a simple yet effective morphological approach to convert a sparse Digital Elevation Model (DEM) to a dense Digital Elevation Model. The conversion is similar to that of the generation of high-resolution DEM from its low-resolution DEM. The approach involves the generation of median contours to achieve the purpose. It is a sequential step of the I) decomposition of the existing sparse Contour map into the maximum possible Threshold Elevation Region (TERs). II) Computing all possible non-negative and non-weighted Median Elevation Region (MER) hierarchically between the successive TER decomposed from a sparse contour map. III) Computing the gradient of all TER, and MER computed from previous steps would yield the predicted intermediate elevation contour at a higher spatial resolution. We presented this approach initially with some self-made synthetic data to show how the contour prediction works and then experimented with the available contour map of Washington, NH to justify its usefulness. This approach considers the geometric information of existing contours and interpolates the elevation contour at a new spatial region of a topographic surface until no elevation contours are necessary to generate. This novel approach is also very low-cost and robust as it uses elevation contours.Comment: 11 pages, 6 figures,1 table, 1 algorith

Increased Functionality of Floodplain Mapping Automation: Utah Inundation Mapping System (UTIMS)

Flood plain mapping has become an increasingly important part of flood plain management. Flood plain mapping employs mapping software and hydraulic calculation packages to efficiently map flood plains. Modelers often utilize automation software to develop the complex geometries required to reduce the time to develop hydraulic models. The Utah Inundation Mapping System (UTIMS) is designed to reduce the time required to develop complex geometries for use in flood plain mapping studies. The automated geometries developed by UTIMS include: flood specific river centerlines, bank lines, flow path lines, cross sections and areal averaged n-value polygons. UTIMS thus facilitates developing automated input to US Army Corps of Engineer\u27s HEC-RAS software. Results from HEC-RAS can be imported back to UTIMS for display and mapping. The user can also specify convergence criteria for water surface profile at selected locations along the river and thus run UTIMS and HEC-RAS iteratively till the convergence criterion is met. UTIMS develops a new flood specific geometry file for each iteration, enabling an accurate modeling of flood-plain. Utilizing this robust and easy to operate software within the GIS environment modelers can significantly reduce the time required to develop accurate flood plain maps. The time thus saved in developing the geometries allows modelers to spend more time doing the actual modeling and analyzing results. The time thus saved can also result in faster turn around and potential cost cutting in flood-plain modeling work. In this paper the authors describe UTIMS capabilities, compare them with other available software, and demonstrate the UTIMS flood plain automation process using a case study