How Can I Integrate Sentinel-2's 20m Resolution Multispectral Data With The Australian Geoscience Data Cube's (AGDC) High-resolution Digital Elevation Model To Develop A More Accurate Fuel Load Estimation Model For Eucalyptus-dominated Forests In Southeastern Australia, Particularly For Areas With High Spatial Heterogeneity In Vegetation Cover And Topography?
To develop a more accurate fuel load estimation model for eucalyptus-dominated forests in southeastern Australia, integrating Sentinel-2 multispectral data with the AGDC's high-resolution DEM, follow this structured approach:
1. Data Preparation
- Coordinate System Alignment: Ensure both Sentinel-2 and AGDC DEM are in the same spatial reference system.
- Spatial Extent Matching: Clip both datasets to the study area of interest.
- Resolution Handling: Resample the AGDC DEM to match Sentinel-2's 20m resolution to maintain consistency.
2. Feature Extraction
- Sentinel-2 Bands: Extract relevant bands (e.g., B4, B3, B2, B8, B11, B12) and compute vegetation indices (NDVI, EVI, NBR).
- DEM Derivatives: Calculate topographical features such as slope, aspect, and curvature using GIS tools.
3. Temporal Consideration
- Use Sentinel-2 time-series data to capture seasonal variations in vegetation, which can inform fuel load dynamics.
4. Model Development
- Machine Learning Approach: Use Random Forest for its ability to handle diverse data and capture non-linear relationships.
- Feature Combination: Stack Sentinel-2 indices with DEM derivatives. Consider PCA for dimensionality reduction if needed.
- Ground Truth Data: Collect field measurements for training and validation, ensuring a robust dataset.
5. Model Training and Application
- Training: Split data into training and validation sets. Use cross-validation to assess model performance.
- Application: Apply the trained model to predict fuel loads across the study area, generating a detailed fuel load map.
6. Validation and Refinement
- Accuracy Assessment: Compare predictions with validation data to evaluate accuracy.
- Model Adjustment: Refine the model by adjusting features or algorithms as needed, considering existing studies for insights.
7. Considerations and Tools
- Software: Use Python libraries (GDAL, scikit-learn, Geopandas) and QGIS for data processing and visualization.
- Limitations: Address potential issues like cloud cover and spatial resolution mismatches with appropriate techniques.
8. Documentation and Interpretability
- Documentation: Thoroughly document the process for reproducibility and transparency.
- Interpretability: Analyze feature importance from Random Forest to understand key factors influencing fuel loads.
By systematically integrating multispectral and topographical data, this approach aims to enhance fuel load estimation accuracy, particularly in areas with high spatial heterogeneity.