SAC_Head_Buhrig_Metrics

SAC_Head_Buhrig_Metrics v1.0.1 Public Stable Release This release documents the first stable and fully reproducible implementation of a geometric and computational pipeline for Bührig-type transverse and longitudinal morphometric metrics applied to the head of the San Antonio Submarine Canyon System (Chile). PROJECT ARCHITECTURE SAC_Head_Buhrig_Metrics/│├── channels/│ ├── CCh_Cartagena_Channel/│ ├── ECh_Emily_Channel/│ ├── MCh_Main_Channel/ ← Fully documented open example│ ├── SACh_SanAntonio_Channel/│ └── SDCh_SantoDomingo_Channel/│├── common_data/│ ├── DEM/│ │ └── SAC_HEAD_TIFF_UTM18S.tif│ └── canyon_edges/│ └── SAC_Head_Edges.shp│├── docs/│ └── METHODOLOGY.md│├── README.md├── LICENSE├── CITATION.cff└── requirements.txt The directory common_data stores shared regional datasets, including: DEM generated from SHOA bathymetric CSV data (WGS84) Ordinary kriging interpolation Reprojection to WGS 1984 UTM Zone 18S (EPSG:32718) 32-bit floating GeoTIFF 30.37 m spatial resolution 635 × 598 pixels Bathymetric range: -12.7 m to -794.9 m Each channel folder represents an independent geometric unit processed under an identical reproducible workflow. Only MCh_Main_Channel is fully documented as an open reference example. MCh_Main_Channel INTERNAL STRUCTURE channels/MCh_Main_Channel/│├── data/│ ├── raw/│ │ ├── MCh_thalweg.shp│ │ └── MP_transects_CLEAN.shp│ ││ └── processed/│ ├── MCh_profile_keypoints_P1_P2_P3.shp│ ├── MCh_profile_P4.shp│ └── MCh_profile_keypoints_P1_P2_P3_P4.shp│├── outputs/│ ├── validation_profiles/│ ├── all_profiles_MP/│ ├── tables/│ │ └── MCh_thalweg_metrics.csv│ └── figures/│└── src/ ├── 01_MCh_extract_profile_keypoints_P1_P2_P3.py ├── 02_MCh_calculate_P4_Wmax_Dmax_intersection.py ├── 03_MCh_integrate_keypoints_P1_P2_P3_P4.py ├── 04_MCh_calculate_buhrig_metrics.py ├── 05_MCh_test_single_profile_geometry.py ├── 06_MCh_all_profiles.py └── 07_MCh_Thalweg_Metrics.py PIPELINE LOGIC (DETERMINISTIC SEQUENCE) 01 → Extract P1 (thalweg), P2 (left edge), P3 (right edge)02 → Compute P4 via vector projection onto Wmax segment (P2–P3)03 → Integrate P1–P4 keypoints into unified dataset04 → Compute transverse Bührig-type morphometric metrics05 → Single-profile geometric validation06 → Batch validation of all transverse profiles07 → Compute longitudinal thalweg metrics TRANSVERSE METRICS (Script 04) W1 (m) W2 (m) Wmax (m) Dmax (m) H1 (m) H2 (m) B1 (°) B2 (°) SWmax (°) Wmax/Dmax (–) LONGITUDINAL METRICS (Script 07) Computed from 500 equidistant normalized sampling points: L (m) L_straight (m) SIav (–) Δz (m) thGav (m/m) Gradient_max (m/m) GEOMETRIC FRAMEWORK The implementation preserves full geometric rigor: No assumption of orthogonality No symmetry assumptions Explicit vector formalization of P4 Scalene triangle geometry solved using the Law of Cosines Deterministic coordinate system (UTM 18S) All outputs are reproducible, traceable, and version-controlled. SCIENTIFIC SCOPE Application case:Head of the San Antonio Submarine Canyon System (Chile) Channels analyzed: MCh – Main Channel SACh – San Antonio Channel SDCh – Santo Domingo Channel ECh – Emily Channel CCh – Cartagena Channel This release documents the geometric and computational methodology.It does not introduce new scientific interpretations, but formalizes a reproducible implementation framework for Bührig-type metrics. TECHNICAL SPECIFICATIONS Python version: 3.12.5 Libraries: geopandas, rasterio, shapely, numpy, pandas, matplotlib GIS validation environment: ArcGIS (expert geomorphological curation) Author: Marco Antonio Viveros VelásquezYear: 2026All rights reserved.