FLOOD02048 - Laserfiche WebLink

Home Browse Search

SPATIAL DATA ANALYSIS OF NONSTRUCTURAL MEASURES . 1 1 R. P. Webb, and M. W. Burnham, A.M., ASCE ABSTRACT Consistent and expedient evaluations of nonstructural flo~d loss reduction measures for existing and alternative future land use patterns can be performed using spatial analysis concepts. The techniques developed center about the processing of spatial geographic data into a grid cell data bank and the sub- sequent accessing and manipulation of pertinent data variables by a computer program. The results are an automatically constructed elevation-damage function at damage reach index locations for selected land use patterns. The modification of the damage function resulting from specific nonstructural alternatives may be performed by inputting into the computer program a target protection level or a specified stage of protection for selected land use categories. These functions may be analyzed conventionally by damage frequency integration methods or used as input into more complex system models. INTRODUCTION Water resource planners are charged in the plan formulation process to evaluate a broad range of alternative flood loss management measures that will provide flood damage reduction for existing and alternative future land us~ conditions. The plan formulation process is comprised of developing alternative means for accomplishing performance targets and selecting from those alternatives the ones which are the most attractive. One criteria of an attractive alternative is the minimization of environmental impact which has resulted in an increased emphasis in the evaluation of nonstructura1 alternatives. Even with this increased emphasis on less construction >- intensive measures which are less disruptive to the environment, there con- tinues to be a need for the systematic assessment of the economic value of the proposed alternatives. It is desirable that alternatives be compared quickly, with the comparisons based on a consistent methodology. Spatial analysis methods can provide the mechanism for expedient and consistent economic evaluation of alternative flood loss management measures. The methods used include the evaluation of geographic information which has been digitized and stored in computer files in digital form. Each geographic data variable is encoded separately and a registered grid cell representation of each data variable is stored in a sequential grid cell record on a computer file which then represents the data bank. lPlanning Analysis Branch, Corps of,Engineers ~rologic Engineering.Center, Davis,Ca. . .J'