Tab: Forecasting

The Forecasting Tab allows you to forecast the shoreline position based on the Kalman Filter algorithm.

Fig. 36 User interface of Forecasting Tab

Layer

Fig. 37 Layer section in Forecasting Tab

Allows you to select the transects layer to be used for forecasting. In QSCAT, the requirement for forecasting is a transect layer unlike DSAS. This allows you to run the forecasting algorithm without the need to run the shoreline change statistics.

Algorithm

Fig. 38 Algorithm section in Forecasting Tab

Kalman Filter

Based on [Long and Plant, 2012], according to DSAS [Himmelstoss et al., 2018].

Time period

Fig. 39 Time period section in Forecasting Tab

Allows you to select the forecast period (10 or 20 years) from now. “From now” refers to system date when the forecasting algorithm is executed.

Vector layer output

The Kalman Filter forecasting algorithm output three vector layers:

1. Forecasted points is the forecasted points for each transect.

2. Forecasted line is a line string geometry connected by forecasted points.

3. Forecasted polygon is a polygon geometry connected by positive and negative forecasted uncertainty points.

Layers

Table 2 Vector layer output geometry type and name

Layer	Geometry	Name
Forecasted points	Point	forecast_points [<datetime>]
Forecasted line	LineString	forecast_line [<datetime>]
Forecasted polygon	Polygon	forecast_polygon [<datetime>]

Attributes

Forecast points

Table 3 Forecast points attribute table

Field name	Data type	Description
period	integer	Selected forecast year period (10 or 20).
year	integer	Forecasted year calculated based from period.
distance	double	Magnitude value of forecasted distance.
uncertainty	double	Value of forecasted uncertainty.
intersect_x	double	X coordinate of the forecasted point.
intersect_y	double	Y coordinate of the forecasted point.

Forecast line

Table 4 Forecast line attribute table

Field name	Data type	Description
period	integer	Selected forecast year period (10 or 20).
year	integer	Forecasted year calculated based from period.
length	double	Line length of connected forecasted points.

Forecast polygon

Table 5 Forecast polygon attribute table

Field name	Data type	Description
period	integer	Selected forecast year period (10 or 20).
year	integer	Forecasted year calculated based from period.
area	double	Polygon area of connected forecasted uncertainty.