Mark D. Stevens’s scientific contributions

A water budget is important for environmental models such as a fire potential model. For the eastern United States, water budget indices derived from the cumulative interplay of precipitation and evaporation characterizes moisture condi- tions better than the Keech-Byram drought index. Because there are various sources of precipitation and evaporation data, it is difficult to manage those data consistently through time in order to derive cumulative water budget indices. In this study, we developed a water budget management system (WBMS) that downloads climate data and calculates a water budget. A geodatabase was designed to support the WBMS. Finally, the WBMS was tested for mapping fire potential in Mississippi.

Three-dimensional topological data is essential for 3D modeling and application such as emergency management and 3D network analysis. This paper reviewed current 3D topological data model and developed a method to construct 3D topological node-relation data structure from 2D computer aided design (CAD) data. The method needed two steps with medial axis-transformation and topological node-relation algorithms. Using a medial-axis transformation algorithm, the first step is to extract skeleton from wall data that was drawn polygon or double line in a CAD data. The second step is to build a topological node-relation structure by converting rooms to nodes and the relations between rooms to links. So, links represent adjacency and connectivity between nodes (rooms). As a result, with the conversion method 3D topological data for micro-level sub-unit of each building can be easily constructed from CAD data that are commonly used to design a building as a blueprint.