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<br />The implementation of nonstructural flood loss reduction measures <br />typically modify the elevation-damage function of the damage reach and <br />have little effect on the hydrologic response of the system (2). The <br />computer program 'used to construct elevation-damage functions at damage <br />reach index locations for existing or alternative future land use patterns <br />is also used in developing these functions for modified conditions. The <br />types of nonstructural alternatives for which elevation-damage functions <br />may be constructed by the automatic spatial analysis method'are: 1) flood <br />proofing specified land use categories a desired number of feet above or <br />below the ground floor level. 2) flood proofing specified land use cate- <br />gories within a damage reach to a uniform flood protection level, 3) <br />temporary protection of structures and evacuation of contents for damage <br />reaches in response to a flood warning dissemination, 4) permanent relo- <br />cation of structures from flood prone areas. and 5) regulatory policies <br />restricting development in the flood plain. Each of these nonstructural <br />alternatives are evaluated by modifying either the appropriate land use <br />category composite stage _ damage function and/or the elevation-damage <br />function of the grid cells which are to be aggregated to a specified <br />damage index location. <br /> <br />Flood Proofing Land Uses to a Specified Stage;--The flood proofing of <br />selected land use categories to a specified stage results in all grid <br />cells of the land use category being protected to a designated non-damage <br />stage. The assessment of the potential flood damage reduction resulting <br />from uniform flood proofing of specified land use categories is accomplished <br />either by directly modifying the inputted composite stage-damage function <br />or by automatically truncating the composite stage-damage function at the <br />appropriate stage. Fig. 4 Flood Proofing Land Uses tG a Specified Stage <br />schematically illustrates and describes the method used to perform the <br />analysis. The evaluation of existing and alternative future land use <br />patterns for the without condition requires that the nonmodified composite <br />damage function be used to construct the elevation-damage relationship for <br />each cell. When the with condition is analyzed. all 'of the grid cells of <br />land uses categories that are to be flood proofed use the modified composite <br />damage function to construct the elevation-damage function. To illustrate the <br />evaluation of flood proofing only future development. the grid cell in Fig. 4 <br />that is classified as land use 6 is converted to land use 1. In the aggregation <br />process, the base condition composite damage function would be used for the four <br />original grid cells and the modified composite damage function would be used <br />for the converted grid cell. It is possible in a single computer run to <br />uniformly flood proof as many land use categories as desired and each land <br />use category may have its own unique flood proofing level. <br /> <br />,Flood Proofing to' Selected Protection Levels.--Flood proofing specified <br />land uses to a selected protection level within a damage reach requires <br />the computation of the depth of flooding resulting from the protection <br />level event for each grid cell and if a cell is flooded. it is flood <br />proofed to that elevation. As an example. flood proofing a damage reach <br />to a 50-year frequency protection level may require some grid cells of a <br /> <br />10 <br />