[1pt] PR: Unmask leveed areas update

docs/CHANGELOG.md

@@ -377,6 +377,16 @@ This hotfix address a bug within the SRC adjustment routine to filter out USGS g
 
 <br/><br/>
 
+## v4.x.x.x - 2024-04-30 - [PR#1136](https://github.com/NOAA-OWP/inundation-mapping/pull/1136)
+
+Levee-protected areas are associated with levelpaths based on a 1000 m buffer on each side of the levee line. However, not all levees are designed to protect against all associated levelpaths, especially where the levelpath flows through the levee-protected area. Levee-protected areas are unmasked by removing levelpaths from association that don't intersect levees but instead flow around them which allows inundation by these branches.
+
+### Changes
+
+- `src/associate_levelpaths_with_levees.py`: Finds levelpaths that don't intersect levees and removes them from their association with their levee-protected area.
+
+<br/><br/>
+
 ## v4.4.15.0 - 2024-04-17 - [PR#1081](https://github.com/NOAA-OWP/inundation-mapping/pull/1081)
 
 This enhancement includes changes to the SRC calibration routine that uses the USGS published rating curve database. The modifications attempt to mimic the technique used in the stage-based CatFIM where the USGS WSE/flow is propagated upstream and downstream of the gauge location. This closes #892 

src/associate_levelpaths_with_levees.py

@@ -22,7 +22,7 @@ def associate_levelpaths_with_levees(
     out_filename: str,
 ):
     """
-    Finds the level path associated with each levee. Ignores level paths that cross a levee exactly once.
+    Finds the levelpath(s) associated with each levee. Ignores levelpaths that cross a levee exactly once.
 
     Parameters
     ----------
@@ -177,7 +177,6 @@ def associate_levelpaths_with_levees(
                 .reset_index(drop=True)
             )
 
-        # Remove levelpaths that cross the levee exactly once
         for j, row in out_df.iterrows():
             # Intersect levees and levelpaths
             row_intersections = gpd.overlay(
@@ -193,9 +192,23 @@ def associate_levelpaths_with_levees(
             # Select Point geometry type
             row_intersections = row_intersections[row_intersections.geom_type == 'Point']
 
+            # Remove levelpaths that cross the levee exactly once
             if len(row_intersections) == 1:
                 out_df = out_df.drop(j)
 
+            # Find associated levelpaths that don't intersect levees
+            elif row_intersections.empty:
+                # Get levelpaths that intersect leveed areas
+                leveed_area_levelpaths = gpd.overlay(
+                    levelpaths[levelpaths[branch_id_attribute] == row[branch_id_attribute]],
+                    leveed_areas[leveed_areas[levee_id_attribute] == row[levee_id_attribute]],
+                    how='intersection',
+                    keep_geom_type=False,
+                )
+
+                if not leveed_area_levelpaths.empty:
+                    out_df = out_df.drop(j)
+
         out_df.to_csv(out_filename, columns=[levee_id_attribute, branch_id_attribute], index=False)