Update README.md

README.md

@@ -68,6 +68,8 @@ The Curvature layer was calculated from the DEM after applying a smoothing filte
  - Curvature = A + B + C + D
 
 ![image/png](https://cdn-uploads.huggingface.co/production/uploads/651d578a1819d9e5754ffc47/yTA2LxPIXivCDI91R6DlU.png)
+Image source: https://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//00q90000000t000000
+
 A fixed distance L = 10 meters was used to ensure the output captures broader terrain features and appears smoother.
  - The <b>raw</b> folder contains curvature values directly computed from the formula above
    - Edge artifacts were cropped