3. Visualize (no download)¶

With the viz extra (pip install "euroflood[viz]"), a FloodFrame renders straight from the index — no raster download. Static plots use matplotlib; interactive maps use folium. This tutorial tours the two main views (recurrence and footprints) and the options that make them presentation-ready.

From here on we query with shape="bbox" (introduced in tutorial 02) — a clean rectangular ROI, so the maps aren't clipped by Zutphen's jagged boundary that follows the IJssel.

In [1]:

import euroflood as ef

cat = ef.floods("Zutphen, Netherlands", shape="bbox")

import euroflood as ef cat = ef.floods("Zutphen, Netherlands", shape="bbox")

Flood-recurrence heatmap¶

A bare .plot() shows how often each ~90 m pixel flooded (darker = more recorded floods), derived from the index alone:

In [2]:

cat.plot()

cat.plot()

Out[2]:

<Axes: title={'center': 'Flood recurrence (recorded floods per pixel)'}>

It accepts matplotlib-style options — a different colormap, a fixed vmax, and whether to draw the query outline:

In [3]:

cat.plot(cmap="viridis", vmax=5, boundary=False)

cat.plot(cmap="viridis", vmax=5, boundary=False)

Out[3]:

<Axes: title={'center': 'Flood recurrence (recorded floods per pixel)'}>

Pass event_id= to see a single event's footprint instead of the recurrence count:

In [4]:

one = int(cat.iloc[0]["event_id"])
cat.plot(event_id=one)

one = int(cat.iloc[0]["event_id"]) cat.plot(event_id=one)

Out[4]:

<Axes: title={'center': 'Flood footprint — event 4049036842'}>

Add a basemap under any static plot with basemap=True (needs network for the tiles): cat.plot(basemap=True, tiles="grayscale") — presets are grayscale, dark, osm.

Per-event footprints¶

.footprints() returns a GeoDataFrame with one row per event, its extent_km2, and (when available) duration_days — useful as data:

In [5]:

foot = cat.footprints()
foot[["event_id", "date", "extent_km2", "duration_days"]].head()

foot = cat.footprints() foot[["event_id", "date", "extent_km2", "duration_days"]].head()

Out[5]:

	event_id	date	extent_km2	duration_days
0	3732793625	2015-01-12	1.042	42
1	1127339359	2015-03-09	0.492	42
2	436160978	2015-12-28	8.025	56
3	1434935811	2016-01-11	0.201	7
4	2231395711	2016-02-08	4.939	42

The same footprints as a static map, coloured by year:

In [6]:

cat.plot(footprints=True)

cat.plot(footprints=True)

Out[6]:

<Axes: title={'center': 'Flood extents by event'}>

Interactive maps¶

.explore() returns a folium map. The default recurrence view carries hover tooltips (how many floods, when) and a click popup listing the dates. Pass tiles= for a different basemap — "grayscale", "dark", or "osm":

In [7]:

cat.explore(tiles="grayscale")

cat.explore(tiles="grayscale")

Out[7]:

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

cat.explore(footprints=True, tiles="grayscale") instead puts each event on its own toggleable layer, foldered by year — the interactive twin of the static footprints above.