HydroBASINS lev08 watershed · #2080497450
Bassin de la Loire - Bras Saint-Jean
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 : Maine-et-Loire
Sub-basin area
12km²
Upstream area
86 269,2km²
Discharge
782,82m³/s
Mean elev.
29m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 2 basins
- Bassin de L’Aubance193 km²
- Bassin de la Loire37 km²
1 dept-equivalent regions (GADM L2)
- 12.1 km²100.0% of basin
6 communes (GADM L5)Available for FRA, RWA
- Mûrs-Erigné4.69 km²27% commune
- Sainte-Gemmes-sur-Loire4.34 km²30% commune
- Saint-Jean-de-la-Croix1.82 km²93% commune
- Mozé-sur-Louet1.10 km²4% commune
- Denée0.11 km²1% commune
- Angers0.00 km²0% commune
2 intersecting protected areas
Vallée de la Loire de Nantes aux Ponts-de-Cé et ses annexes
IUCN Not ReportedSpecial Protection Area (Birds Directive)
4.61 km² overlap
Vallée de la Loire de Nantes aux Ponts-de-Cé et ses annexes
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
4.61 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
1 896 distinct species · 19 042 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 30 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 la Loire - Bras Saint-Jean : 28 espèces + 2 bulles famille, 73 interactions GloBI documentées sur 2 types (connectance 16.8%, filtre Serrano α=0.2). Les 2 bulles regroupent des espèces visuellement absorbées par famille (≥3 espèces visibles).
Comparaison sur la connectance du réseau local complet vs distribution nationale (toutes les communes françaises).
Hydroclimate (BasinATLAS lev08)
Mean T°
11,6°C
Annual rain
652mm
Moisture idx (CMI)
-0,25
Runoff
227mm/an
PET
868mm
AET
550mm
Mean slope
0,8°
Water table
83cm
Forest
0%
Crops
29%
Urban
22%
Protected
0%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)