Conference Papers

A tide-gate algorithm was added to a one-dimensional unsteady flow model that was calibrated, verified, and used to determine the locations of as many as five tide gates that would maximize flushing in two canal systems. Results from the flow model were used to run a branched Lagrangian transport model to simulate the flushing of a conservative constituent from the canal systems both with and with

The system design is premised on a proven, areal two-dimensional, finite-difference flow/transport model which is supported by an operational set of computer programs for input data management and model output interpretation. The purposes of the project are (1) to demonstrate the utility of the model for providing useful highway design information, (2) to develop guidelines and procedures for usin

Recently, new identification methods have been developed by using the concept of optimal-recursive filtering and stochastic approximation. These methods, known as stochastic identification, are based on the statistical properties of the signal and noise, and do not require the assumptions of current methods. The criterion for stochastic system identification is that the difference between the reco

This paper describes a current national analysis of streamflow data being conducted by the U.S. Geological Survey to identify and map, in a consistent State-by-State format, the frequency and areal distribution of major floods and droughts in the United States. The work is being performed as the latest in a series of National Water Summaries published as Geological Survey Water-Supply Papers. The

No abstract available 

Concentrations of numerous potentially toxic trace elements and pesticides were determined in water, sediment, and biota from the Salton Sea area in southestern California. Comparison of results with data from other studies in this area and from other areas, and with various water-quality standards or criteria, indicate that selenium probably is the principal contaminant of concern in the Salton S

No abstract available.

The National Fisheries Research Center-Great Lakes of the U.S. Fish and Wildlife Service has extensively used a side scan sonar to survey and pinpoint lake trout spawning grounds in the Great Lakes. The Geographic Information System (GIS) of the National Ecology Research Center produced maps from the side scan sonar data showing the exact location of the spawning grounds; this will enable current

No abstract available.

Gridded surface data sets are often incorporated into digital data bases, but extracting information from the data sets requires specialized raster processing techniques different from those historically used on remotely sensed and thematic data. Frequently, the information desired of a gridded surface is directly related to the topologic peaks and pits of the surface. A method for isolating these

No abstract available.

Vector-based geographic information systems usually require annotation, such as a polygon number or attribute data, in a suitable location within a polygon. Traditional methods usually compute the polygon centroid, test the centroid for inclusion or exclusion, and select some alternative point when the centroid falls outside the polygon. Two problems are associated with this approach: (1) the text