Add Topographic Attributes Low
------------------------------


This tool add a number of topographic attributes to the input bathymetric low feature class.

The following attributes are calculated from the bathymetry and slope-gradient rasters to describe the topographic properties of each bathymetric high feature.

1. *headDepth*: water depth at the head point of the feature polygon, along the long axis
2. *footDepth*: water depth at the foot point of the feature polygon, along the long axis
3. *head_foot_depthRange*: the difference in water depth between the head point and the foot point of the feature polygon
4. *head_foot_gradient*: the slope-gradient between the head point and the foot point of the feature polygon, which is calculated by equation :eq:`slope-gradient-low`

   .. math::
     :label: slope-gradient-low
   
     \arctan(\frac{head\_foot\_depthRange}{head\_foot\_length})

5. *minDepth*: the minimum water depth within the feature polygon
6. *maxDepth*: the maximum water depth within the feature polygon
7. *depthRange*: the difference in water depth within the feature polygon, which is calculated by equation :eq:`depth-range-low`

.. math::
   :label: depth-range-low

    (maxDepth - minDepth)

8. *meanDepth*: the mean water depth within the feature polygon
9. *stdDepth*: the standard deviation of the water depths within the feature polygon
10. *minGradient*: the minimum slope-gradient within the feature polygon
11. *maxGradient*: the maximum slope-gradient within the feature polygon
12. *gradientRange*: the difference in slope-gradient within the feature polygon, which is calculated by equation :eq:`gradient-range-low`

   .. math::
     :label: gradient-range-low
   
     (maxGradient - minGradient)

13. *meanGradient*: the mean slope-gradient within the feature polygon
14. *stdGradient*: the standard deviation of the slope-gradients within the feature polygon


.. image:: images/topographic_attributes1_2.png
   :align: center


.. code-block:: python
   :linenos:

   import arcpy
   from arcpy import env
   from arcpy.sa import *
   arcpy.CheckOutExtension("Spatial")
   
   # import the python toolbox
   arcpy.ImportToolbox("C:/semi_automation_tools/User_Guide/Tools/AddAttributes.pyt")
   
   env.workspace = 'C:/semi_automation_tools/testSampleCode/Gifford.gdb'
   env.overwriteOutput = True
   
   # specify input and output parameters of the tool
   inFeat = 'test_BL'
   inBathy = 'gifford_bathy'
   inSlope = 'gifford_slope'
   headFeat = 'test_BL_head'
   footFeat = 'test_BL_foot'
   
   # execute the tool
   arcpy.AddAttributes.Add_Topographic_Attributes_Low_Tool(inFeat,inBathy,inSlope,headFeat,footFeat)