HydroBASINS lev08 watershed · #2080568970
Bassin de Ruisseau de Merlet
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 : Tarn-et-Garonne
Sub-basin area
175,9km²
Upstream area
5 176km²
Discharge
56,79m³/s
Mean elev.
131m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 2 basins
- Bassin de la Lère411 km²
- Bassin de l'Aveyron227 km²
1 dept-equivalent regions (GADM L2)
- 176.2 km²100.0% of basin
17 communes (GADM L5)Available for FRA, RWA
- Montauban45.75 km²34% commune
- L'Honor-de-Cos23.43 km²73% commune
- Génébrières18.12 km²98% commune
- Saint-Étienne-de-Tulmont17.59 km²82% commune
- Léojac11.97 km²95% commune
- Lamothe-Capdeville11.61 km²100% commune
- Monclar-de-Quercy7.96 km²21% commune
- Albias7.58 km²35% commune
- Vaïssac7.24 km²19% commune
- Piquecos6.31 km²80% commune
- Mirabel5.08 km²16% commune
- Villemade4.60 km²49% commune
- Montastruc3.94 km²88% commune
- Lafrançaise3.67 km²7% commune
- Nègrepelisse0.68 km²1% commune
- Saint-Nauphary0.63 km²3% commune
- La Salvetat-Belmontet0.05 km²0% commune
2 intersecting protected areas
Vallées du Tarn, de l'Aveyron, du Viaur, de l'Agout et du Gijou
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
1.28 km² overlap
Biotope Protection Order
0.69 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
1 905 distinct species · 32 943 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 36 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 Ruisseau de Merlet : 30 espèces + 6 bulles famille, 62 interactions GloBI documentées sur 4 types (connectance 9.8%, filtre Serrano α=0.2). Les 6 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°
12,8°C
Annual rain
740mm
Moisture idx (CMI)
-0,26
Runoff
250mm/an
PET
995mm
AET
625mm
Mean slope
3,0°
Water table
162cm
Forest
6%
Crops
89%
Urban
3%
Protected
0%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)