CSBAT was developed using a combination of Visual Basic programming and ArcGIS customization, utilizing spatial and non-spatial data stored within a geodatabase environment. The CSBAT was designed around six components: Sediment Sources; Receiver Sites; Transportation Modes and Cost; Recreational Usage and Benefit; Cost Benefit Analyses, and Environmental Considerations. Each component was developed with regional data and finite options. However, the model has been designed to accommodate future expansion of data sources and model capabilities.Sediment Sources
The CSBAT was designed to have the option of sediment sources from offshore, harbors and inland (such as dams and debris basins) with user-specified sediment volumes at each sediment source. For each sediment source, a geo-spatial location is identified and tied into the transportation network for cost calculations. Sediment volumes are also tied into the beach nourishment calculations.
Available beach characteristics of the receiver sites are stored within the geodatabase and used with the beach nourishment calculations. The beach nourishment calculations to determine the increase in beach width over time are based on site-specific characteristics. The CSBAT application has also been designed to accommodate an extendable list of potential beach receiver sites.
Transportation Modes and Cost
CSBAT calculates costs associated with various transportation modes once a Source and Receiver site has been selected. This was accomplished by developing a multi-nodal transportation network that has the Source and Receiver sites built into it as transportation stops (nodes) along a network of roads, rail lines, coastlines, and ocean tow routes. The transportation networks were built using ArcGIS 9.1 Network Analyst. All GIS data originally came from sources such as the Army Corps of Engineers and the State of California. Transportation costs are calculated based on the distance traveled along the network from the source to the receiver sites including all the mobilization and demobilization of equipment.
Recreational Usage and Benefit
The CSBAT application calculates the existing and estimated increase in recreational value at the receiver site after beach nourishment assuming some increment in beach width. Elements used to calculate the recreational benefit increase include: Weather, Water Quality, Beach Width and Quality, Overcrowding, Facilities/Services, and Availability of Substitutes. Additional information on Annual Attendance and Overnight/Day Use spending are used to convert the day use values into Annual Recreational Value, Local and State Spending, and Local and State Tax Generation.
Cost and Benefit Analyses
The CSBAT application calculates the Benefit/Cost (B/C) Ratio based on the selected source and receiver site, the calculated recreational benefits, quantity of sediment used for beach nourishment, and the transportation mode.
The CSBAT application has been designed to report on environmental considerations associated with transporting sediments from the source to the receiver site, and those associated with beach nourishment activities at each receiver site. The data tables for the Receiver beaches were developed by a review of historical records.