| --- | |
| --- | |
| # Vector Layers | |
| The heart of this application design is a vector dataset serialized as both (Geo)Parquet and PMTiles. | |
| The parquet version allows for real-time calculations through rapid SQL queries via duckdb, | |
| and the PMTiles version allows the data to be quickly visualized at any zoom through maplibre. | |
| maplibre can also efficiently filter the PMTiles data given a feature ids returned by duckdb. | |
| `gdal_translates` can generate both PMTiles and geoparquet, though `tippecanoe` provides more | |
| options for PMTiles generation and can produce nicer tile sets. | |
| The demo uses the CDC Social Vulnerability data because it is built on the hierachical partitioning | |
| used by the Census (Country->State->County->Tract) hierarchy. | |
| # Raster Layers | |
| ## Generating static tiles | |
| ## Zonal statistics calculations | |
| The application is essentially driven by the vector layer data using SQL. | |
| I find it helpful to pre-process 'zonal' calculations, e.g. the mean value of each raster layer | |
| within each feature in the 'focal' vector data set(s). | |