HydroBASINS lev08 watershed · #2080488710
Bassin de l'Aff
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 : Ille-et-Vilaine, Morbihan
Sub-basin area
736,9km²
Upstream area
737km²
Discharge
12,28m³/s
Mean elev.
77m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
2 dept-equivalent regions (GADM L2)
- 373.2 km²50.5% of basin
- 365.8 km²49.5% of basin
40 communes (GADM L5)Available for FRA, RWA
- Maure-de-Bretagne63.95 km²96% commune
- Carentoir59.10 km²100% commune
- Paimpont55.70 km²51% commune
- Guer52.21 km²100% commune
- Campénéac49.25 km²81% commune
- Augan37.57 km²93% commune
- Sixt-sur-Aff35.24 km²80% commune
- Monteneuf29.84 km²100% commune
- Beignon25.56 km²100% commune
- Bains-sur-Oust21.91 km²48% commune
- Plélan-le-Grand19.87 km²40% commune
- Guignen19.47 km²37% commune
- Tréal18.09 km²94% commune
- Comblessac17.46 km²100% commune
- Mernel16.45 km²99% commune
- La Gacilly16.06 km²100% commune
- Porcaro15.64 km²100% commune
- Bruc-sur-Aff15.51 km²74% commune
- Quelneuc13.83 km²100% commune
- La Chapelle-Bouëxic13.10 km²63% commune
- Pipriac13.00 km²26% commune
- Saint-Nicolas-du-Tertre12.39 km²93% commune
- Les Brulais12.04 km²100% commune
- Bovel11.55 km²79% commune
- Lieuron11.38 km²68% commune
- Campel11.25 km²100% commune
- Maxent11.16 km²28% commune
- Cournon11.08 km²100% commune
- Saint-Séglin9.31 km²100% commune
- La Chapelle-Gaceline7.70 km²100% commune
- Loutehel7.47 km²100% commune
- Glénac6.80 km²51% commune
- Les Fougerêts4.97 km²24% commune
- Réminiac3.60 km²30% commune
- Saint-Malo-de-Beignon3.37 km²100% commune
- Ploërmel3.34 km²6% commune
- Ruffiac2.15 km²6% commune
- Caro0.45 km²1% commune
- Saint-Martin-sur-Oust0.20 km²1% commune
- Tréhorenteuc0.02 km²0% commune
4 intersecting protected areas
Forêt de Paimpont
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
4.01 km² overlap
Marais de Vilaine
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
2.33 km² overlap
Landes De Monteneuf
IUCN IVRegional Nature Reserve
1.22 km² overlap
Le Haut Sourdréac
IUCN IVBiotope Protection Order
0.04 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
3 833 distinct species · 230 112 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 43 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 l'Aff : 17 espèces reliées par 224 interactions GloBI sur 6 types (connectance 11.8%, filtre Serrano α=0.2). 45 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
771mm
Moisture idx (CMI)
0,00
Runoff
526mm/an
PET
774mm
AET
562mm
Mean slope
2,2°
Water table
212cm
Forest
5%
Crops
64%
Urban
0%
Protected
0%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)