HydroBASINS lev08 watershed · #2080549270
Bassin de Olona
A watershed (drainage basin) is not a body of water — it is the land area where rainfall converges towards a single river that eventually reaches the sea (or an endorheic basin). Boundaries follow ridgelines.
Crosses 5 administrative regions : Como, Milano, Monza and Brianza, Pavia, Varese
Sub-basin area
949,6km²
Upstream area
949,6km²
Discharge
25,37m³/s
Mean elev.
203m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
5 dept-equivalent regions (GADM L2)
- 360.7 km²37.9% of basin
- 216.3 km²22.7% of basin
- 166.4 km²17.5% of basin
- 163.4 km²17.2% of basin
- 45.1 km²4.7% of basin
22 intersecting protected areas
Regional/Provincial Nature Park
36.76 km² overlap
Boschi delle Groane
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
6.91 km² overlap
Monte Legnone e Chiusarella
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
2.90 km² overlap
Pineta pedemontana di Appiano Gentile
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
2.20 km² overlap
Pineta di Cesate
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
1.82 km² overlap
Parco Regionale Campo dei Fiori
IUCN Not ReportedSpecial Protection Area (Birds Directive)
1.43 km² overlap
Regional/Provincial Nature Park
1.43 km² overlap
Regional/Provincial Nature Reserve
0.81 km² overlap
Garzaia di Porta Chiossa
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.81 km² overlap
13 more protected areassorted by overlap area
Garzaia di Porta Chiossa
IUCN Not ReportedSpecial Protection Area (Birds Directive)
0.81 km² overlap
Regional/Provincial Nature Reserve
0.40 km² overlap
Fontanile Nuovo
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.40 km² overlap
Riserva Regionale Fontanile Nuovo
IUCN Not ReportedSpecial Protection Area (Birds Directive)
0.37 km² overlap
Oasi di Lacchiarella
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.37 km² overlap
Garzaia della Carola
IUCN Not ReportedSpecial Protection Area (Birds Directive)
0.20 km² overlap
Garzaia della Carola
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.20 km² overlap
Regional/Provincial Nature Reserve
0.19 km² overlap
Bosco di Vanzago
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.17 km² overlap
Bosco di Vanzago
IUCN Not ReportedSpecial Protection Area (Birds Directive)
0.17 km² overlap
Regional/Provincial Nature Reserve
0.17 km² overlap
Po da Albaredo Arnaboldi ad Arena Po
IUCN Not ReportedSpecial Protection Area (Birds Directive)
0.04 km² overlap
Monte Martica
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.03 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
3 006 distinct species · 101 522 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 35 species (selected proportionally per kingdom among those with at least one documented interaction here) to keep the graph readable. Hover for details, click to explore the full ecosystem of a species.
ℹ️ The territory contains many more species than displayed and all their documented interactions: the graph is intentionally the structural skeleton (top-N species by composite local score, edges filtered by Serrano 2009 disparity filter α=0.2).
Indicateurs du tissu écologique
Tissu écologique de Bassin de Olona : 27 espèces dont 3 patrimoniales (LR IUCN CR/EN/VU) reliées par 90 interactions GloBI sur 5 types (connectance 14.3%, filtre Serrano α=0.2). 9 bulles taxonomiques (cascade genre/famille GloBI, ≥3 espèces).
Comparaison sur la connectance du réseau local complet vs distribution nationale (toutes les communes françaises).
Hydroclimate (BasinATLAS lev08)
Mean T°
12,3°C
Annual rain
1 098mm
Moisture idx (CMI)
0,15
Runoff
836mm/an
PET
925mm
AET
764mm
Mean slope
1,3°
Water table
60cm
Forest
13%
Crops
27%
Urban
72%
Protected
4%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)