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Spatial-data management techniques allow convenient, cost-effective representation of the spatially-varying data that are necessary for effective water and related-land resources planning. Application of the techniques began in the U.S. Army Corps of Engineers in the early 1970's as an experiment. Since then, the techniques have been used for regional planning studies, major flood-control studies, and limited-scope investigations. The HEC-SAM software, developed and supported by the staff of the Hydrologic Engineering Center (HEC), has made practical these applications. Keywords: Geographic information systems; Data bases.

An ensemble of analytic tools is used to identify capacity expansion alternatives for the Delaware River dredged-material disposal system. Characteristics of the river and riparian area are stored and analyzed with a geographic information system. Site attractiveness maps produced with these data yield an array of potential expansion sites. The least-costly schedule for acquisition of these sites is identified with branch-and-bound enumeration. For the enumeration, the operation cost of alternative expansion plans is evaluated with a network-flow programming model of the disposal system. (Author)

The goals of nonstructural flood-control planning are formulation, evaluation, selection, and implementation of a practicable management plan that provides optimal protection from the adverse effects of flooding. Many alternative flood-control measures can be dismissed by the water resources planner on the basis of judgement, but a substantial number will require detailed analysis before a suitable plan can be selected. This analysis is an iterative process, requiring input from the planar at each step. Software developed at the Hydrologic Engineering Center (HEC) allows efficient data storage in a structure-oriented data bank and provides for selective retrieval and manipulation of the data from an interactive terminal. Thus the planner is able to propose nonstructural measures and to evaluate rapidly the economic and technical feasibility of those measures in a iterative scheme that allows the required input from the planner. An application of the interactive plan evaluation software is presented. Steps in creating the data bank are defined, and use of the software for subsequent accessing and manipulating the data for plan evaluation is discussed. (Author)

Computer program HEC-1, a precipitation-runoff model widely used throughout the United States, includes the capability to estimate automatically any of twelve parameters necessary to model the precipitation-runoff process and the channel routing process. The parameter estimation scheme employs Newton's method to minimize a weighted sum of squares of differences between observed and computed hydrograph values. Applications of this parameter estimation procedure are presneted, and typical steps of the procedure for deterimining optimal parameter estimates are outlined. Recent efforts to improve the estimation algorithm and recent use of the calibration capability to update sequentially parameter estimates in a flood forecasting application are discussed. (Author)

The Dredged Material Disposal Management Model (D2M2) is a simulation-optimization model designed to provide information required to answer the following disposal management questions: a. If a specified long-term operation policy is followed for an existing or proposed dredged material disposal system, what is the final status of the system, given the initial conditions, system physical and economic characteristics, and dredged material volume estimates? Must additional disposal site capacity be provided? b. What is the least costly long-term operation policy for an existing or proposed disposal system, given initial conditions, system physical and economic characteristics, and dredged material volume estimates? c. What is the least costly method to provide the additional volume required? Should expired leases be extended, or should new sites be acquired? d. If new sites are to be acquired, what is the least costly combination of sites? What is the least costly combination of sites? What is the least costly sequence for acquiring these sites. e. Are material management alternatives, such as transferring material or resting sites, cost effective?, This article is from 'United States - The Netherlands Meeting on Dredging and Related Technology (3rd) Held in Charleston, South Carolina on 10-14 September 1984,' AD-A182 670, p77-83.