Changelog

Version 1.0.0 - October 14, 2025

🎯 Major Achievement: First Direct Polygon-Based Global Tidal Basin Database

This release marks a breakthrough in estuarine biogeochemistry: the world’s first comprehensive, high-resolution tidal basin atlas using direct polygon measurement from BasinATLAS Level 7, classified with the corrected Dürr et al. (2011) typology.

📊 Dataset Summary

Primary Dataset: tidal_basins_river_based_lev07.gpkg

• 16,189 tidal basins (BasinATLAS Level 7 resolution)
• 36.6 million km² total catchment area
• 0-300 km from coast (tidal influence zone)
• Dual classification: Dürr coastline (ocean basins) + catchments (upstream)

Classification Breakdown (Corrected Dürr 2011 Types)

| Type | Count | Area (km²) | % | Description | |——|——-|———–|—|————-| | Tidal systems (Type II) | 4,666 | 11,100,845 | 28.8% | Wave/tide-dominated | | Small deltas (Type I) | 4,036 | 9,915,216 | 24.9% | River-dominated, small-medium | | Fjords and fjaerds (Type IV) | 3,516 | 6,677,945 | 21.7% | Glacially carved | | Lagoons (Type III) | 1,577 | 3,513,555 | 9.7% | Barrier-protected | | Arheic (Type VII) | 1,218 | 2,576,910 | 7.5% | Arid/arheic coasts | | Large Rivers (Type Va) | 375 | 1,015,438 | 2.3% | Major rivers | | Large Rivers + tidal deltas (Type Vb) | 227 | 605,466 | 1.4% | Major deltas (Mekong, etc.) | | Karst (Type VI) | 153 | 433,585 | 0.9% | Limestone karst systems | | Unclassified | 421 | 725,316 | 2.6% | No Dürr match |

🔬 Scientific Corrections Implemented

1. Corrected Dürr et al. (2011) Type Mapping

# CORRECTED MAPPING
0:  'Endorheic or Glaciated'
1:  'Small deltas'              # Type I (was wrongly "Delta")
2:  'Tidal systems'             # Type II (was wrongly "Lagoon")
3:  'Lagoons'                   # Type III (was wrongly "Fjord")
4:  'Fjords and fjaerds'        # Type IV (was wrongly "Coastal Plain")
5:  'Large Rivers'              # Type Va (was wrongly "Karst")
51: 'Large Rivers with tidal deltas'  # Type Vb (was wrongly "Small deltas")
6:  'Karst'                     # Type VI
7:  'Arheic'                    # Type VII

Impact:

• ✅ Mekong Delta now correctly classified as “Large Rivers with tidal deltas” (Type Vb)
• ✅ Saigon River now correctly classified as “Tidal systems” (Type II)

2. Strict Classification Priority

Ocean basins (DIST_SINK=0): Coastline classification ONLY (absolute priority) Upstream basins: Use catchment classification Fallback: Ocean basins without coastline match use catchment

This ensures coastal morphology determines ocean basin types, not inland watershed characteristics.

🗺️ Interactive Visualization Improvements

Diagnostic Maps (diagnostics_html/)

1. tidal_basins_web.html (22.8 MB)
   • Clean map with basins, Dürr coastline, Dürr catchments
   • Side-by-side pie charts (bottom-right)
   • Layer control with checkboxes
2. tidal_basins_with_rivers.html (175.5 MB)
   • Same as above + 148,824 large river segments (GRIT)
   • Rivers filtered: Strahler order ≥ 6 OR mainstem
   • For diagnostic/validation purposes

Features

• ✅ Real pie charts (Chart.js) showing area distribution
• ✅ Checkbox layer control (toggle on/off)
• ✅ Correct Dürr colors matching official types
• ✅ Tooltips with basin details (name, type, area, distance)

🔧 Technical Implementation

Data Processing Pipeline

1. BasinATLAS Level 7 (520,000 basins globally)
   ↓ Filter: ENDO=0 & DIST_SINK ≤ 300 km
   ↓ 16,194 tidal basins

2. Classify with Dürr 2011
   ↓ Method 1: Spatial intersection with catchments
   ↓ Method 2: Nearest coastline for ocean basins
   ↓ Priority: Coastline > Catchment

3. Clean & Filter
   ↓ Remove basins < 5 km²
   ↓ 16,189 final basins

4. Output
   ↓ GPKG (full resolution): 380 MB
   ↓ GeoJSON (web): 28.5 MB (simplified geometries)

Key Scripts

• scripts/diagnostics/create_tidal_basins_river_based.py: Main processing script
• scripts/web_optimization/create_web_tidal_basins.py: Web optimization

📁 Files Included in This Release

Data Files (data/processed/)

• ✅ tidal_basins_river_based_lev07.gpkg (380 MB) - PRIMARY DATASET
• ✅ tidal_basins_river_based_lev07_web.geojson (5.1 MB) - Web version

Web Files (data/web/)

• ✅ tidal_basins_precise.geojson (28.5 MB) - NEW! For website
• ✅ tidal_basins_stats.json - Summary statistics

Diagnostic Maps (diagnostics_html/)

• ✅ tidal_basins_web.html (22.8 MB)
• ✅ tidal_basins_with_rivers.html (175.5 MB)

Documentation

• ✅ Updated README.md with corrected Dürr types
• ✅ This RELEASE_NOTES.md

🔮 Next Steps

Immediate (v1.1)

• Add GlobSalt salinity predictions
• Integrate DynQual physics-based features
• ML model for gaps in Dürr classification

Future (v2.0)

• Delineate Tidal Freshwater Zones (TFZ) globally
• Add OSM water body polygons (actual water surface)
• Calculate precise water surface areas (not catchments)

🙏 Acknowledgments

Data Sources

• Dürr et al. (2011): Estuary typology framework
• HydroSHEDS BasinATLAS v1.0: Level 7 basin polygons
• GRIT v0.6: Global river network topology
• GlobSalt v2.0: Salinity monitoring network

Software

• GeoPandas, Folium, Chart.js: Geospatial processing & visualization
• AI-Assisted Development: GitHub Copilot for rapid prototyping

📜 Citation

When using this dataset, please cite:

Nguyen, T. A. (2025). Global Tidal Basin Surface Area Atlas v1.0. 
GitHub: https://github.com/NguyenTruongAnLab/estuary-type-map
Based on Dürr et al. (2011) DOI: 10.1007/s12237-011-9381-y