Transects_OpenOcean.shp - Digital Shoreline Analysis System version 4.3 Transects with Linear Regression Rate Calculations for the Open Ocean coast of Dauphin Island, Alabama.

Unique identification number of the baseline segment. If BaselineID=0 no transects will be generated. Used by DSAS to determine transect ordering alongshore if multiple baseline segments exist.

Assigned by DSAS based on ordering of transects along the baseline. Used to allow user to sort transect data along the baseline from baseline start to baseline end.

Assigned by DSAS, automatically, to record the date and time a transect was processed.

Assigned by DSAS to indicate whether or not a transect was automatically created by DSAS (1= transect was auto generated by DSAS; 0=transect was not auto-generated).

Assigned by DSAS, automatically, to record the X coordinate of the beginning of the transect.

Assigned by DSAS, automatically, to record the Y coordinate of the beginning of the transect.

Assigned by DSAS, automatically, to record the X coordinate of the end of the transect.

Assigned by DSAS, automatically, to record the Y coordinate of the end of the transect.

Assigned by DSAS to record the azimuth of the transect, measured in degrees clockwise from North.

The transect change distance - or distance of the transect along shore, in meters.

For all MHW (lidar) shorelines from 1998-2014: A linear regression rate-of-change statistic was calculated by fitting a least-squares regression line to all shoreline points for a particular transect. The best-fit regression line is placed so that the sum of the squared residuals (determined by squaring the offset distance of each data point from the regression line and adding the squared residuals together) is minimized. The linear regression rate is the slope of the line. The rate is reported in meters per year with positive values indicating accretion and negative values indicating erosion. Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.

For all MHW (lidar) shorelines from 1998-2014: The R-squared statistic, or coefficient of determination, is the percentage of variance in the data that is explained by a regression. It is a dimensionless index that ranges from 1.0 to 0.0 and measures how successfully the best-fit line accounts for variation in the data. The smaller the variability of the residual values around the regression line relative to the overall variability, the better the prediction (and closer the R-squared value is to 1.0). Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.

For all MHW (lidar) shorelines from 1998-2014: The predicted (or estimated) values of y (the distance from baseline in meters) are computed for each shoreline point by using the values of x (the shoreline date) and solving the equation for the best-fit regression line (y=mx+b). The standard error is also called the standard deviation. Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.

For all MHW (lidar) shorelines from 1998-2014: The standard error of the slope with confidence interval describes the uncertainty of the reported rate. The LRR rates are determined by a best-fit regression line for the shoreline data at each transect. The slope of this line is the reported rate of change (in meters/year). The confidence interval (LCI) is calculated by multiplying the standard error (also called the standard deviation) of the slope by the two-tailed test statistic at the user-specified 90 percent confidence. This value is often reported in conjunction with the slope to describe the confidence of the reported rate. For example: LRR = 1.2 LCI90 = 0.7 could be reported as a rate of 1.2 (+/-) 0.7 meters/year. Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.

For all WDL (aerial) shorelines from 1940-2015: A linear regression rate-of-change statistic was calculated by fitting a least-squares regression line to all shoreline points for a particular transect. The best-fit regression line is placed so that the sum of the squared residuals (determined by squaring the offset distance of each data point from the regression line and adding the squared residuals together) is minimized. The linear regression rate is the slope of the line. The rate is reported in meters per year with positive values indicating accretion and negative values indicating erosion. Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.

For all WDL (aerial) shorelines from 1940-2015: The R-squared statistic, or coefficient of determination, is the percentage of variance in the data that is explained by a regression. It is a dimensionless index that ranges from 1.0 to 0.0 and measures how successfully the best-fit line accounts for variation in the data. The smaller the variability of the residual values around the regression line relative to the overall variability, the better the prediction (and closer the R-squared value is to 1.0). Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.

For all WDL (aerial) shorelines from 1940-2015: The predicted (or estimated) values of y (the distance from baseline in meters) are computed for each shoreline point by using the values of x (the shoreline date) and solving the equation for the best-fit regression line (y=mx+b). The standard error is also called the standard deviation. Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.

For all WDL (aerial) shorelines from 1940-2015: The standard error of the slope with confidence interval describes the uncertainty of the reported rate. The LRR rates are determined by a best-fit regression line for the shoreline data at each transect. The slope of this line is the reported rate of change (in meters/year). The confidence interval (LCI) is calculated by multiplying the standard error (also called the standard deviation) of the slope by the two-tailed test statistic at the user-specified 90 percent confidence. This value is often reported in conjunction with the slope to describe the confidence of the reported rate. For example: LRR = 1.2 LCI90 = 0.7 could be reported as a rate of 1.2 (+/-) 0.7 meters/year. Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.

For all WDL (aerial) and MHW (lidar) shorelines from 1940-2015: A linear regression rate-of-change statistic was calculated by fitting a least-squares regression line to all shoreline points for a particular transect. The best-fit regression line is placed so that the sum of the squared residuals (determined by squaring the offset distance of each data point from the regression line and adding the squared residuals together) is minimized. The linear regression rate is the slope of the line. The rate is reported in meters per year with positive values indicating accretion and negative values indicating erosion. Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.

For all WDL (aerial) and MHW (lidar) shorelines from 1940-2015: The R-squared statistic, or coefficient of determination, is the percentage of variance in the data that is explained by a regression. It is a dimensionless index that ranges from 1.0 to 0.0 and measures how successfully the best-fit line accounts for variation in the data. The smaller the variability of the residual values around the regression line relative to the overall variability, the better the prediction (and closer the R-squared value is to 1.0). Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.

For all WDL (aerial) and MHW (lidar) shorelines from 1940-2015: The predicted (or estimated) values of y (the distance from baseline in meters) are computed for each shoreline point by using the values of x (the shoreline date) and solving the equation for the best-fit regression line (y=mx+b). The standard error is also called the standard deviation. Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.

For all WDL (aerial) and MHW (lidar) shorelines from 1940-2015: The standard error of the slope with confidence interval describes the uncertainty of the reported rate. The LRR rates are determined by a best-fit regression line for the shoreline data at each transect. The slope of this line is the reported rate of change (in meters/year). The confidence interval (LCI) is calculated by multiplying the standard error (also called the standard deviation) of the slope by the two-tailed test statistic at the user-specified 90 percent confidence. This value is often reported in conjunction with the slope to describe the confidence of the reported rate. For example: LRR = 1.2 LCI90 = 0.7 could be reported as a rate of 1.2 (+/-) 0.7 meters/year. Null values are locations where there were not enough shoreline data (minimum of four shorelines) present to generate a linear regression rate of change (or any associated statistics) and are identified as 9999.