HydroBASINS lev08 watershed · #2080021220
Bassin du Blavet
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 2 administrative regions : Côtes-d'Armor, Morbihan
Sub-basin area
2 054,1km²
Upstream area
2 054,2km²
Discharge
48,07m³/s
Mean elev.
148m
Administrative coverage
2 dept-equivalent regions (GADM L2)
- 1322.7 km²64.2% of basin
- 737.5 km²35.8% of basin
103 communes (GADM L5)Available for FRA, RWA
- Pluméliau68.18 km²100% commune
- Cléguérec63.26 km²100% commune
- Bubry57.97 km²83% commune
- Noyal-Pontivy54.06 km²100% commune
- Moréac53.91 km²90% commune
- Baud47.74 km²97% commune
- Languidic47.15 km²45% commune
- Guern45.88 km²98% commune
- Inzinzac-Lochrist44.90 km²100% commune
- Plounévez-Quintin43.11 km²100% commune
- Quistinic42.80 km²100% commune
- Naizin41.70 km²100% commune
- Plouguernével41.64 km²100% commune
- Saint-Nicolas-du-Pélem41.24 km²100% commune
- Glomel41.23 km²52% commune
- Melrand40.46 km²100% commune
- Malguénac38.39 km²100% commune
- Lanrivain37.56 km²100% commune
- Rostrenen32.52 km²100% commune
- Canihuel32.47 km²100% commune
- Plumelin32.00 km²100% commune
- Séglien31.89 km²83% commune
- Neulliac31.33 km²100% commune
- Mûr-de-Bretagne31.21 km²100% commune
- Kergrist-Moëlou31.05 km²65% commune
- Kergrist29.80 km²100% commune
- Moustoir-Ac29.48 km²87% commune
- Guénin29.11 km²100% commune
- Saint-Mayeux28.88 km²94% commune
- Réguiny27.66 km²100% commune
- Saint-Aignan27.39 km²100% commune
- Remungol27.10 km²100% commune
- Plélauff25.94 km²100% commune
- Inguiniel25.35 km²49% commune
- Laniscat25.16 km²100% commune
- Pontivy24.95 km²100% commune
- Maël-Pestivien24.16 km²75% commune
- Silfiac22.75 km²100% commune
- Plussulien22.38 km²100% commune
- Saint-Thuriau21.97 km²100% commune
- Saint-Barthélemy21.80 km²100% commune
- Kerien21.75 km²98% commune
- La Chapelle-Neuve21.57 km²100% commune
- Mellionnec20.54 km²84% commune
- Hennebont19.64 km²100% commune
- Bieuzy19.29 km²100% commune
- Kerfourn19.10 km²100% commune
- Lanvaudan18.51 km²100% commune
- Saint-Gelven18.11 km²100% commune
- Saint-Gérand18.06 km²100% commune
- Sainte-Brigitte18.01 km²100% commune
- Saint-Gilles-Vieux-Marché17.69 km²81% commune
- Lescouët-Gouarec17.46 km²91% commune
- Crédin17.29 km²52% commune
- Camors16.60 km²45% commune
- Radenac16.29 km²75% commune
- Le Sourn16.28 km²100% commune
- Peumerit-Quintin14.97 km²100% commune
- Saint-Guen14.96 km²82% commune
- Le Haut-Corlay14.75 km²57% commune
- Caudan14.47 km²33% commune
- Trémargat13.71 km²100% commune
- Caurel13.63 km²100% commune
- Saint-Igeaux12.95 km²100% commune
- Sainte-Tréphine12.56 km²100% commune
- Perret12.25 km²100% commune
- Moustoir-Remungol12.13 km²100% commune
- Saint-Connec10.88 km²100% commune
- Corlay10.78 km²77% commune
- Saint-Gilles-Pligeaux10.51 km²54% commune
- Kervignac7.33 km²18% commune
- Calan6.94 km²57% commune
- Gouarec6.74 km²100% commune
- Cléguer6.47 km²20% commune
- Le Quillio6.41 km²39% commune
- Gueltas6.17 km²30% commune
- Paule6.11 km²16% commune
- Plouay5.82 km²9% commune
- Locmalo5.29 km²22% commune
- Locminé5.00 km²100% commune
- Bignan4.82 km²10% commune
- Saint-Nicodème4.48 km²26% commune
- Lanester3.82 km²22% commune
- Saint-Caradec3.78 km²17% commune
- Magoar3.46 km²45% commune
- Croixanvec3.20 km²52% commune
- Bourbriac3.10 km²4% commune
- Pleugriffet2.97 km²8% commune
- Merléac2.89 km²9% commune
- Le Vieux-Bourg2.80 km²11% commune
- Saint-Gonnery1.88 km²11% commune
- Ploërdut1.87 km²2% commune
- Saint-Allouestre1.52 km²9% commune
- Plouray1.37 km²3% commune
- Kerpert1.21 km²6% commune
- Langoëlan1.07 km²5% commune
- Brandivy0.36 km²1% commune
- Hémonstoir0.24 km²2% commune
- Grand-Champ0.23 km²0% commune
- Pluvigner0.20 km²0% commune
- Bulat-Pestivien0.14 km²0% commune
- Colpo0.14 km²1% commune
- Saint-Servais0.05 km²0% commune
19 intersecting protected areas
Biotope Protection Order
39.41 km² overlap
Biotope Protection Order
17.40 km² overlap
Têtes de bassin du Blavet et de l'Hyères
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
16.79 km² overlap
Biotope Protection Order
16.48 km² overlap
Special Areas of Conservation (Habitats Directive)
9.25 km² overlap
Rivière Scorff, Forêt de Pont Calleck, Rivière Sarre
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
8.50 km² overlap
Biotope Protection Order
5.02 km² overlap
Complexe de l'est des montagnes noires
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
3.50 km² overlap
Saint-Aignan (De)
IUCN IaForest Integral Biological Reserve
1.13 km² overlap
10 more protected areassorted by overlap area
Landes Et Marais De Glomel
IUCN IVRegional Nature Reserve
0.75 km² overlap
Toul-Goulic
IUCN Not ReportedGeotope Protection Order
0.23 km² overlap
Rivière Elle
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.08 km² overlap
Le Breuil du Chêne
IUCN Not ReportedGeotope Protection Order
0.03 km² overlap
La butte de Malvran
IUCN Not ReportedGeotope Protection Order
0.02 km² overlap
Biotope Protection Order
0.02 km² overlap
Forêt de Lorge, landes de Lanfains, cime de Kerchouan
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.01 km² overlap
Chiroptères du Morbihan
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.00 km² overlap
Rivière Leguer, forêts de Beffou, Coat an Noz et Coat an Hay
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.00 km² overlap
Biotope Protection Order
0.00 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
4 028 distinct species · 219 052 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 38 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 du Blavet : 24 espèces dont 3 patrimoniales (LR IUCN CR/EN/VU) reliées par 101 interactions GloBI sur 6 types (connectance 14.4%, filtre Serrano α=0.2). 14 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°
10,8°C
Annual rain
912mm
Moisture idx (CMI)
0,24
Runoff
722mm/an
PET
695mm
AET
549mm
Mean slope
2,7°
Water table
169cm
Forest
1%
Crops
60%
Urban
2%
Protected
0%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)