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Geo Tab


Click on the Geo tab to obtain the following:



This tab contains the functions and parameters associated with performing a geospatial analysis. A geospatial analysis refers to modeling information or behavior on a spatial scale. The well known contour map is an example of a geospatial analysis. SADA provides five major spatial routines: inverse distance, ordinary kriging, indicator kriging, nearest neighbor, and natural neighbor. These routines appear in the drop down box at the top of the tab. See Overview of Geospatial Modeling.


Depending on the selected routine, certain parameters become important. The Block Size parameters are used to divide the site into a series of blocks. See Overview of Geospatial Modeling and Setting up the Grid.


The Geospatial Model Parameters are used to define what data the interpolant will use in contouring. See Defining a Neighborhood. The Power parameter is associated with the inverse distance method only.


Near the bottom of the tab is the Use Only Selected Data option. Select this box to only use data enclosed within a polygon in geospatial calculations. Note: this does not automatically apply to the experimental variography functions. A separate option on the experimental variography window must be checked in order to enforce this constraint.


The next option is Start Estimation at Depth Zero. This option becomes active for three-dimensional data and forces SADA to start the contouring grid at a depth equal to zero. Otherwise, the top of the contouring grid will begin at the smallest depth value found in the data set.


The last option on the tab is Assume Lognormal (see Setting Normality/Lognormality Assumption).


If you choose Pooled Data from the drop down list in the contaminant names box (middle of the second toolbar), the Geo tab looks like this. (See Pooling Data.)





During Pooled data operations, geospatial modeling is constrained to risk mapping and risk-based remedial design (See Risk Maps and Area of Concern Maps.) The Geospatial Model Parameters, which previously showed parameters for a given contaminant, now changes to Registered Contaminants. This allows the user to see what contaminants have been registered for the current analysis. In general, all contaminants in the current media should be visible. Note: the individual geospatial parameters are no longer visible but still apply in modeling their respective contaminants. During pooled data geospatial modeling, each contaminant is independently contoured with separate specified interpolation schemes. The results are then summed within the spatial risk framework. (See Spatial Risk Issues.)