31:T52c,makeMap = (year, { w = width / 4, h = width / 4, grouped = false } = {}) => { const maxYear = year === 2016 ? 2021 : year + 4; const yearFormat = d3.format(""); return Plot.plot({ width: w, insetTop: 30, height: h, marks: [ // Boundaries Plot.geo(boundariesProj, { stroke: "#f3f3f3", strokeWidth: 0.5, strokeOpacity: 0.3, fill: "#f3f3f3", fillOpacity: 0.1 }), // Wildfire shapes Plot.geo(fires, { filter: (d) => year === "all" ? true : grouped ? d.id > year && d.id <= maxYear : +d.id === year, strokeWidth: 1, stroke: (d) => +d.id, fill: (d) => +d.id }), // label Plot.text([year], { frameAnchor: "top", dy: 10, fontSize: 14, fontFamily: "sans-serif", text: (d) => year === "all" ? "Wildfies, 1986 - 2021" : grouped ? `${yearFormat(year)} - ${yearFormat(maxYear)}` : yearFormat(year), fill: "white" }), // outline Plot.frame({ stroke: "#f3f3f3" }) ], x: { axis: null }, y: { axis: null }, color: { scheme: "Reds" }, style: { backgroundColor: "black" } }); }32:T9f9,```bash #!/bin/bash # Make sure these are installed # npm install -g shapefile # npm install -g ndjson-cli # npm install -g @mapbox/geojson-merge # Track number of fires per year num_fires=() # A quick variable to switch in case you need to download the data download=false # Iterate through available years for i in {1986..2021} do # Variation in file name for 2021 version='20210810' if [ $i -eq 2021 ]; then version='20220624' fi STUB='nbac_'$i'_r9_'$version # Download files if [ $download = true ]; then FOLDER='nbac_'$i'.zip' curl 'https://cwfis.cfs.nrcan.gc.ca/downloads/nbac/'$STUB'.zip' --output $FOLDER unzip -o $FOLDER for extension in .zip .CPG .dbf .prj .sbx .sbn .shp.xml .shx do rm $STUB''$extension done rm $FOLDER fi # Couldn't figure out how to structure these steps with pipes.... # Convert shapefile to geojson shp2json $STUB'.shp' -o nbac_geo.json # Quite redundant, but convert to ndjson to count the number of fires shp2json -n $STUB'.shp' -o nbac_ndgeo.json # Count the number of fires (stored separately in metadata) num_fires+=($(ndjson-reduce < nbac_ndgeo.json "p + 1" "0")) # Convert geojson to topojson geo2topo fires=nbac_geo.json > nbac_topo.json # Quantize values (remove unnecessary decimals in coordinates) topoquantize 1e5 < nbac_topo.json > nbac_quantized.json # Simplify: the parameter of 10 was a bit of a guess toposimplify -s 10 -f < nbac_quantized.json > nbac_topo_simple.json # Merge all years into a single feature topomerge fires=fires < nbac_topo_simple.json -k $i -o nbac_merged.json # Convert back to geojson for Plotting topo2geo fires=- < nbac_merged.json > 'nbac_geo_'$i'.json' done # Clean up rm nbac_geo.json rm nbac_topo.json rm nbac_topo_simple.json rm nbac_quantized.json rm nbac_merged.json rm nbac_ndgeo.json # Merge into a single geojson file geojson-merge ./nbac_geo*.json > fires.json # Quantize the merged file to make it smaller (surprised this makes it smaller) geo2topo fires=fires.json > nbac_topo_TMP.json topoquantize 1e5 < nbac_topo_TMP.json > nbac_quantized_TMP.json topo2geo fires=- < nbac_quantized_TMP.json > simple.json # Remove these "TMP" files: is this bad....? ls | grep TMP | xargs rm # Save the metadata as a .csv file file="metadata.csv" echo '"year", "numFires"' > $file for i in "$\{!num_fires[@]}"; do year=$((1986 + $i)) printf '"%s","%s"\n' "$\{year}" "$\{num_fires[i]}" done >> "$file" ```33:[{"id":"40086fd8b32e4228abc6c9244ce41e077843441ef8d9f161e12ed487e39e8e789dfca6292f4f27b525f1fbe05e9c44516410b76e35c824affb7f8376075e0983","href":"https://static.observableusercontent.com/files/40086fd8b32e4228abc6c9244ce41e077843441ef8d9f161e12ed487e39e8e789dfca6292f4f27b525f1fbe05e9c44516410b76e35c824affb7f8376075e0983","name":"boundaries@2.json","type":"application/json","lastModified":1687380324982.294,"size":7099371},{"id":"45aacbb54c420be02550f728ea744726c4f27341b2c32f31148f6206168578c950b65b4d1da47fa58481f3177884cd90b2306eeb67382059289d83848291aaf6","href":"https://static.observableusercontent.com/files/45aacbb54c420be02550f728ea744726c4f27341b2c32f31148f6206168578c950b65b4d1da47fa58481f3177884cd90b2306eeb67382059289d83848291aaf6","name":"simple@3.json","type":"application/json","lastModified":1687285682314.879,"size":29599848},{"id":"545f8d989e22b86314fc5d3d1ccf20e437bdc1d48a2dbf14f9426c7c2b26c54096093b6cd844b6e72f14eaff078713b21ea170c5d79d7ba74d9df2f159afb7d7","href":"https://static.observableusercontent.com/files/545f8d989e22b86314fc5d3d1ccf20e437bdc1d48a2dbf14f9426c7c2b26c54096093b6cd844b6e72f14eaff078713b21ea170c5d79d7ba74d9df2f159afb7d7","name":"mismatch.png","type":"image/png","lastModified":1687889152347.828,"size":499309}] 2f:{"title":"Canadian Wildfires","cells":[{"id":0,"value":"# Canadian Wildfires\nData was downloaded from [Natural Resources Canada](https://cwfis.cfs.nrcan.gc.ca/datamart/download/nbac), discovered via [Data Is Plural](https://www.data-is-plural.com/). \n\n\nSee this [alternative notebook](https://observablehq.com/@mkfreeman/canadian-wildfires-2) for a faster rendering of each incident as a circle. ","pinned":false,"hidden":false,"mode":"md"},{"id":640,"value":"viewof view = Inputs.radio([\"Single map\", \"5 year groups\"], {\n label: \"Choose a view (~10s loading time)\",\n value: \"Single map\"\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":172,"value":"{\n await visibility();\n return view !== \"Single map\"\n ? html`

\n ${d3.range(1986, 2021, 5).map((d) => makeMap(d, { grouped: true }))} \n

`\n : makeMap(\"all\", { w: width, h: width / 2 });\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":682,"value":"Plot.legend({\n color: {\n type: \"linear\",\n scheme: \"reds\",\n domain: [1986, 2021],\n tickFormat: (d) => d,\n label: \"Year\"\n }\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":658,"value":"---\n## Mapping code","pinned":false,"hidden":false,"mode":"md"},{"id":54,"value":"$31","pinned":true,"hidden":false,"mode":"ojs"},{"id":425,"value":"boundaries = FileAttachment(\"boundaries@2.json\").json()","pinned":true,"hidden":false,"mode":"ojs"},{"id":84,"value":"fires = FileAttachment(\"simple@3.json\").json()","pinned":true,"hidden":false,"mode":"ojs"},{"id":203,"value":"---\n## Data \nData was downloaded from [Natural Resources Canada](https://cwfis.cfs.nrcan.gc.ca/datamart/download/nbac). While they provide a single \"combined\" file from 1986 - 2021, that file was too large (1.5G) to process using command line tools, and obviously too large to host and work with on Observable.\n\nBelow is a bash script used to: \n- Download the shapefiles\n- Convert to geojson\n- Convert to topojson (for simplification)\n- Simplify the shapefiles to reduce their size\n- Merge files into a single geojson file\n\nLuckily, this [set of tutorials](https:#medium.com/@mbostock/command-line-cartography-part-1-897aa8f8ca2c) helped outline the necessary steps!\n","pinned":false,"hidden":false,"mode":"md"},{"id":216,"value":"$32","pinned":false,"hidden":false,"mode":"md"},{"id":206,"value":"---\n## Province Shapefile\nThe province [shapefile.zip](https://www12.statcan.gc.ca/census-recensement/2021/geo/sip-pis/boundary-limites/files-fichiers/lpr_000b21a_e.zip) was downloaded from [statistics Canada](https://www12.statcan.gc.ca/census-recensement/2021/geo/sip-pis/boundary-limites/index2021-eng.cfm?year=21). This file was also too large to process using command line tools, so was simplified using the UI tool [mapshaper](https://mapshaper.org/).","pinned":false,"hidden":false,"mode":"md"},{"id":305,"value":"Unfortunately, the shapefile's projection didn't match the projection of the wildfires. ","pinned":false,"hidden":false,"mode":"md"},{"id":666,"value":"mismatch = FileAttachment(\"mismatch.png\").image({ width: 640 })","pinned":false,"hidden":false,"mode":"ojs"},{"id":302,"value":"I tried using the [Canada Lambert Conformal Conic](https://spatialreference.org/ref/esri/canada-lambert-conformal-conic/) projection that was reference in the `.prj` file, but that was still misaligned.","pinned":false,"hidden":false,"mode":"md"},{"id":309,"value":"Finally, with a tip from [@Fil](https://observablehq.com/@fil) - and [stackexchange](https://gis.stackexchange.com/questions/55196/how-can-i-get-the-proj4-string-or-epsg-code-from-a-shapefile-prj-file) - , I used `gdalsrsinfo` to construct the proj4js string from the .prj file (). \n\nHad to download ~~[GDAL here](https://gdal.org/download.html#current-release)~~ \n\n`brew install gdal` (took a while, at least 30 mins on coffee shop wifi! Wow there were a lot of dependencies here...).\n\nThen retrieved the projections using: \n\n```bash\n# Get wildfire projection string\ngdalsrsinfo nbac.shp\n\n# Get the boundary projection string\nlpr_000b21a_e.prj\n```","pinned":false,"hidden":false,"mode":"md"},{"id":339,"value":"// gdalsrsinfo lpr_000b21a_e.prj\nboundaryProj = `+proj=lcc +lat_0=63.390675 +lon_0=-91.8666666666667 +lat_1=49 +lat_2=77 +x_0=6200000 +y_0=3000000 +datum=NAD83 +units=m +no_defs`","pinned":true,"hidden":false,"mode":"ojs"},{"id":343,"value":"// gdalsrsinfo nbac_2020_r9_20210810.prj\nfireProj = `+proj=lcc +lat_0=49 +lon_0=-95 +lat_1=49 +lat_2=77 +x_0=0 +y_0=0 +datum=NAD83 +units=m +no_defs`","pinned":true,"hidden":false,"mode":"ojs"},{"id":264,"value":"proj4 = require(\"proj4@2.8\")","pinned":true,"hidden":false,"mode":"ojs"},{"id":569,"value":"// A function to recursively project coordinates in a geoJSON object\nfunction recurseProject(coordsArr) {\n if (Array.isArray(coordsArr[0])) return coordsArr.map(recurseProject);\n return proj4(boundaryProj, fireProj, coordsArr); // project the coordinates from one projection to the other\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":261,"value":"// Do the projection of all coordinates\nboundariesProj = {\n return {\n type: \"FeatureCollection\",\n features: boundaries.features.map((feature) => {\n return {\n ...feature,\n geometry: {\n type: feature.geometry.type,\n coordinates: recurseProject(feature.geometry.coordinates)\n }\n };\n })\n };\n}","pinned":true,"hidden":false,"mode":"ojs"}],"files":"$W33","stdlib":"1","titling":"auto"}