HydroBASINS lev08 watershed · #2080574100
Bassin du Grand Valat
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 : Bouches-du-Rhône, Gard
Sub-basin area
82,4km²
Upstream area
95 065km²
Discharge
1 724,2m³/s
Mean elev.
36m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 2 basins
- Bassin de l'Alzon1992 km²
- Bassin de la Durance110 km²
2 dept-equivalent regions (GADM L2)
- 69.0 km²83.6% of basin
- 13.5 km²16.4% of basin
11 communes (GADM L5)Available for FRA, RWA
- Beaucaire22.26 km²26% commune
- Jonquières-Saint-Vincent20.44 km²96% commune
- Tarascon13.10 km²18% commune
- Manduel8.37 km²32% commune
- Comps6.76 km²80% commune
- Vallabrègues6.54 km²46% commune
- Redessan4.41 km²28% commune
- Boulbon0.42 km²2% commune
- Montfrin0.22 km²1% commune
- Bellegarde0.04 km²0% commune
- Meynes0.01 km²0% commune
3 intersecting protected areas
Costières nîmoises
IUCN Not ReportedSpecial Protection Area (Birds Directive)
18.20 km² overlap
Le Rhône aval
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
5.93 km² overlap
costieres de nimes
IUCN IVLand acquired by a regional conservatory of natural areas
0.27 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
2 631 distinct species · 36 847 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 Grand Valat : 31 espèces + 7 bulles famille, 58 interactions GloBI documentées sur 5 types (connectance 8.3%, filtre Serrano α=0.2). Les 7 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°
13,9°C
Annual rain
703mm
Moisture idx (CMI)
-0,31
Runoff
304mm/an
PET
1 019mm
AET
593mm
Mean slope
1,3°
Water table
129cm
Forest
2%
Crops
49%
Urban
17%
Protected
0%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)