Fire Analysis

KrishV — Wed, 09 Dec 2020 04:25:13 GMT

Hi Everyone,

I'm trying to use California wildfires 2017 - Thomas Fire analysis Sample provided in ArcGIS Python API Samples.

I have used sentinel imagery to do the same analysis but I always end up getting black imagery (All 0s). Can you please suggest where I'm doing wrong?

import arcgis from arcgis import * from arcgis.mapping import MapImageLayer gis = GIS(profile="krishna_dev") #Sentinel2 sentinel_item = gis.content.search('title:Sentinel2', 'Imagery Layer', outside_org=True)[0] sentinel = sentinel_item.layers[0] sentinel_item aoi = {'spatialReference': {'latestWkid': 3857, 'wkid': 102100}, 'type': 'extent', 'xmax': 9028482.969, 'xmin': 8908018.212, 'ymax': 2478700.211, 'ymin': 2248166.133} arcgis.env.analysis_extent = {'xmax': 9028482.969, 'xmin': 8908018.212, 'ymax': 2478700.211, 'ymin': 2248166.133, "spatialReference":{"wkid":102100,"latestWkid":3857}} sentinel.extent = aoi import pandas as pd from datetime import datetime selected = sentinel.filter_by(where="(Category = 1)", time=[datetime(2020, 4, 3), datetime(2020, 4, 15)], geometry=arcgis.geometry.filters.intersects(aoi)) df = selected.query(out_fields="acquisitiondate, name, cloudcover", order_by_fields="acquisitiondate").sdf df['acquisitiondate'] = pd.to_datetime(df['acquisitiondate'], unit='ms') df.tail() prefire = sentinel.filter_by('OBJECTID in ( 10127407, 10187367)') # 2020-04-03 prefire = prefire.blend() midfire = sentinel.filter_by('OBJECTID in (10304749, 10304746)') # 2020-04-13 midfire = midfire.blend() from arcgis.raster.functions import * extracted_band = extract_band(midfire, [13,12,4]) extracted_band_prefire = extract_band(prefire, [13,12,4]) nbr_prefire = band_arithmetic(prefire, "(b9 - b13) / (b9 + b13) + 2000") nbr_postfire = band_arithmetic(midfire, "(b9 - b13) / (b9 + b13) + 2000") nbr_diff = nbr_prefire - nbr_postfir nbr_diff burnt_areas = colormap(remap(nbr_diff, input_ranges=[0.1, 0.27, # low severity 0.27, 0.44, # medium severity 0.44, 0.66, # moderate severity 0.66, 1.00], # high severity burn output_values=[1, 2, 3, 4], no_data_ranges=[-1, 0.1], astype='u8'), colormap=[[4, 0xFF, 0xC3, 0], [3, 0xFA, 0x8E, 0], [2, 0xF2, 0x55, 0], [1, 0xE6, 0, 0]]) burnt_areas

Thanks,

Krish

Re: Fire Analysis

DanPatterson — Tue, 08 Dec 2020 11:13:36 GMT

You would be better served if you posted your code...

Code formatting ... the Community Version - GeoNet, The Esri Community

Re: Fire Analysis

KrishV — Tue, 08 Dec 2020 12:42:49 GMT

Hi @DanPatterson ,

I attached the entire notebook in the zip file.

Thanks,

Krish

Re: Fire Analysis

DanPatterson — Tue, 08 Dec 2020 14:24:16 GMT

So you want people to run the notebook rather than examine the code?

Re: Fire Analysis

KrishV — Wed, 09 Dec 2020 04:23:03 GMT

Hi @DanPatterson ,

Updated the post with code!

Thanks,

Krish

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