HydroBASINS lev08 watershed · #2080484470
Bassin de Canal de Nantes à Brest - L'Oust Canalisé
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 1 administrative regions : Morbihan
Sub-basin area
245,1km²
Upstream area
1 149,2km²
Discharge
22,84m³/s
Mean elev.
97m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 2 basins
- Bassin du Lié475 km²
- Bassin de l'Oust429 km²
21 communes (GADM L5)Available for FRA, RWA
- Guégon53.49 km²100% commune
- Lanouée39.67 km²90% commune
- Pleugriffet28.69 km²74% commune
- Guéhenno18.15 km²77% commune
- Saint-Servant17.91 km²80% commune
- Cruguel15.21 km²87% commune
- Guillac13.27 km²60% commune
- Les Forges11.47 km²21% commune
- Billio8.50 km²70% commune
- Lantillac7.36 km²100% commune
- Buléon6.75 km²55% commune
- La Croix-Helléan6.07 km²42% commune
- Radenac4.98 km²23% commune
- Josselin4.60 km²100% commune
- Quily4.51 km²86% commune
- Plumelec2.89 km²5% commune
- Lizio1.13 km²7% commune
- Bignan0.81 km²2% commune
- Le Roc-Saint-André0.23 km²2% commune
- Bréhan0.10 km²0% commune
- Saint-Allouestre0.04 km²0% commune
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
1 399 distinct species · 39 598 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 45 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 Canal de Nantes à Brest - L'Oust Canalisé : 34 espèces dont 2 patrimoniales (LR IUCN CR/EN/VU) reliées par 104 interactions GloBI sur 5 types (connectance 10.5%, filtre Serrano α=0.2). 11 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°
11,1°C
Annual rain
831mm
Moisture idx (CMI)
0,12
Runoff
603mm/an
PET
731mm
AET
556mm
Mean slope
2,4°
Water table
182cm
Forest
1%
Crops
74%
Urban
0%
Protected
0%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)