{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Comparison of dNBR for three wild fires in 2018 and 2019\n", "\n", "This notebook contains the calculations necessary for mapping the burn severity of the previously selected products.\n", "This burn severity is measured as the ${\\Delta}NBR$, which is defined as:\n", "\n", "$$\n", "{\\Delta}NBR = NBR_\\text{pre-fire} - NBR_\\text{post-fire}\n", "$$\n", "\n", "Instead of only calculating values by overlaying different bands in one product, the ${\\Delta}NBR$ adds a time dimension to determine changes that have occured in the time span between the two chosen products.\n", "\n", "## Methodology\n", "\n", "The $NBR$ of the products downloaded in the previous notebook is calculated using the notebook **TODO**.\n", "These $NBR$ values are plotted side-by-side to get a visual impression of the changes that may have occured between two given dates.\n", "The ${\\Delta}NBR$ is calculated and, if showing signs of burned areas, compared to data given by the responsible German ministries.\n", "\n", "## Calculcations\n", "### Setup" ] }, { "cell_type": "code", "execution_count": 1, "metadata": {}, "outputs": [], "source": [ "from pathlib import Path\n", "import geopandas as gpd\n", "\n", "from sentinel_helpers import geodataframe_on_map, scihub_band_paths\n", "nbr_path = Path('output/spectral_indices/')\n", "product_path = Path('input/forest_fires/')" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Treuenbrietzen (Postdam-Mittelmark) 2018\n", "\n", "The first case is the wild fire in August 2018 that led to the evacuation of three villages (source).\n", "We load the pre-calculated NBR values and geometries we fetched from OpenStreetMap:" ] }, { "cell_type": "code", "execution_count": 2, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "[PosixPath('output/spectral_indices/T33UUT_20180807T101021_NBR_10m.tif'),\n", " PosixPath('output/spectral_indices/T33UUT_20180822T101019_NBR_10m.tif'),\n", " PosixPath('output/spectral_indices/T33UUT_20180919T102021_NBR_10m.tif')]" ] }, "execution_count": 2, "metadata": {}, "output_type": "execute_result" } ], "source": [ "potsdam_mittelmark_nbr_2018 = list(sorted(nbr_path.glob('*2018*NBR*.tif')))\n", "potsdam_mittelmark_nbr_2018" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "The `postdam_mittelmark_geom` is a collection of three points:" ] }, { "cell_type": "code", "execution_count": 3, "metadata": {}, "outputs": [ { "data": { "text/html": [ "
| \n", " | place_id | \n", "osm_type | \n", "osm_id | \n", "display_name | \n", "place_rank | \n", "category | \n", "type | \n", "importance | \n", "icon | \n", "geometry | \n", "
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | \n", "3285415 | \n", "node | \n", "387079362 | \n", "Frohnsdorf, Treuenbrietzen, Potsdam-Mittelmark... | \n", "19 | \n", "place | \n", "village | \n", "0.495 | \n", "https://nominatim.openstreetmap.org/ui/mapicon... | \n", "POINT (12.90217 52.05466) | \n", "
| 1 | \n", "554316 | \n", "node | \n", "226935349 | \n", "Klausdorf, Treuenbrietzen, Potsdam-Mittelmark,... | \n", "19 | \n", "place | \n", "village | \n", "0.495 | \n", "https://nominatim.openstreetmap.org/ui/mapicon... | \n", "POINT (12.94213 52.04879) | \n", "
| 2 | \n", "303964452 | \n", "node | \n", "282202396 | \n", "Tiefenbrunnen, Treuenbrietzen, Potsdam-Mittelm... | \n", "22 | \n", "place | \n", "isolated_dwelling | \n", "0.420 | \n", "None | \n", "POINT (12.94439 52.03532) | \n", "