5. Global flood hazard (GLOFAS)¶

Alongside the historic flood maps, hazard(...) queries the modelled CEMS-GLOFAS flood-hazard maps by return period (the depth expected on average once every N years). Hazard catalogues are just as actionable as historic ones — the same .download(), .stats(), .plot(), and .explore() all work.

This tutorial downloads real hazard tiles, so it needs network access.

In [1]:

from pathlib import Path

import euroflood as ef

ef.settings.output_dir = Path("out")

from pathlib import Path import euroflood as ef ef.settings.output_dir = Path("out")

Query the 100- and 500-year return periods for Zutphen. One row per return period (supported: 10, 20, 50, 75, 100, 200, 500):

In [2]:

haz = ef.hazard("Zutphen, Netherlands", return_period=[100, 500], shape="bbox")
haz

haz = ef.hazard("Zutphen, Netherlands", return_period=[100, 500], shape="bbox") haz

Out[2]:

EuroFlood catalogue: 2 hazard layers · RP 100, 500 yr · 166.3 km² total · ⬇ 2/2 downloaded

	collection	return_period	model_version	n_tiles	filename	area_km2	geometry	path
0	hazard	100	v2.1.2	1	hazard_RP100.tif	83.144	POLYGON ((6.14039 52.08873, 6.27499 52.08873, ...	out/hazard_RP100_8277ba1c.tif
1	hazard	500	v2.1.2	1	hazard_RP500.tif	83.144	POLYGON ((6.14039 52.08873, 6.27499 52.08873, ...	out/hazard_RP500_8277ba1c.tif

Download and measure them. GLOFAS depth is already in metres and is reported as-is (EFAS historic depth is centimetres; the scale is chosen automatically per catalogue).

In [3]:

haz = haz.download()
haz.stats()

haz = haz.download() haz.stats()

Out[3]:

	return_period	wet_pixels	max_depth_m	mean_depth_m	p95_depth_m	flooded_area_km2	volume_m3	volume_Mm3
0	100	13558	5.752	2.213	4.017	80.0169	177115974.3	177.1160
1	500	13823	6.139	2.548	4.384	81.5809	207891205.5	207.8912

Static and interactive depth maps¶

Render the 100-year hazard depth as a static image…

In [4]:

rp100 = haz[haz["return_period"] == 100]
rp100.plot(depth=True)

rp100 = haz[haz["return_period"] == 100] rp100.plot(depth=True)

Out[4]:

<Axes: title={'center': 'Flood depth — hazard_RP100_8277ba1c'}>

…and as an interactive folium overlay you can pan and zoom:

In [5]:

rp100.explore(depth=True, tiles="grayscale")

rp100.explore(depth=True, tiles="grayscale")

Out[5]:

Make this Notebook Trusted to load map: File -> Trust Notebook

The recurrence/footprint views are historic-only (hazard has no event index), so a hazard .explore() without depth= shows a context map of the queried area:

In [6]:

haz.explore(tiles="grayscale")

haz.explore(tiles="grayscale")

Out[6]:

Make this Notebook Trusted to load map: File -> Trust Notebook

In [ ]: