import pystac_client import planetary_computer import odc.stac import geopandas as gpd import dask.distributed import matplotlib.pyplot as plt import rioxarray from datetime import datetime, timedelta def stac_search(box, datetime): # STAC Search for this imagery in space/time window items = ( pystac_client.Client. open("https://planetarycomputer.microsoft.com/api/stac/v1", modifier=planetary_computer.sign_inplace). search(collections=["sentinel-2-l2a"], bbox=box, datetime=datetime, query={"eo:cloud_cover": {"lt": 10}}). item_collection()) return items def compute_nbs(items, box): # Time to compute: client = dask.distributed.Client() # landsat_bands = ["nir08", "swir16"] sentinel_bands = ["B08", "B12", "SCL"] # NIR, SWIR, and Cloud Mask # The magic of gdalwarper. Can also resample, reproject, and aggregate on the fly data = odc.stac.load(items, bands=sentinel_bands, bbox=box ) # Compute the Normalized Burn Ratio, must be float swir = data["B12"].astype("float") nir = data["B08"].astype("float") # can resample and aggregate in xarray. compute with dask nbs = (((nir - swir) / (nir + swir)). # resample(time="MS"). # median("time", keep_attrs=True). compute() ) return nbs nps = gpd.read_file("/vsicurl/https://huggingface.co/datasets/cboettig/biodiversity/resolve/main/data/NPS.gdb") calfire = gpd.read_file("/vsicurl/https://huggingface.co/datasets/cboettig/biodiversity/resolve/main/data/fire22_1.gdb", layer = "firep22_1") # fire = gpd.read_file("/vsizip/vsicurl/https://edcintl.cr.usgs.gov/downloads/sciweb1/shared/MTBS_Fire/data/composite_data/burned_area_extent_shapefile/mtbs_perimeter_data.zip" # extract and reproject the Joshua Tree NP Polygon jtree = nps[nps.PARKNAME == "Joshua Tree"].to_crs(calfire.crs) # All Fires in the DB that intersect the Park jtree_fires = jtree.overlay(calfire, how="intersection") # Extract a polygon if interest. > 2015 for Sentinel, otherwise we can use LandSat recent = jtree_fires[jtree_fires.YEAR_ > "2015"] big = recent[recent.Shape_Area == recent.Shape_Area.max()].to_crs("EPSG:4326") # Get bounding box + dates before & after fire for STAC search box = big.buffer(0.01).bounds.to_numpy()[0] # Fire bbox + buffer alarm_date = datetime.strptime(big.ALARM_DATE.item(), "%Y-%m-%dT%H:%M:%S+00:00") before_date = alarm_date - timedelta(days=14) after_date = alarm_date + timedelta(days=14) search_dates = before_date.strftime("%Y-%m-%d") + "/" + after_date.strftime("%Y-%m-%d") def run(): # here we go! items = stac_search(box, search_dates) nbs = compute_nbs(items, box) # write first and last date to tif nbs.isel(time=0).rio.to_raster(raster_path="before.tif", driver="COG") nbs.isel(time=(nbs.time.size-1)).rio.to_raster(raster_path="after.tif", driver="COG") if __name__ == "__main__": run()