HydroBASINS lev08 watershed · #2080572670
Bassin du Bès
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 : Landes
Sub-basin area
284,1km²
Upstream area
284,1km²
Discharge
5,31m³/s
Mean elev.
74m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
1 dept-equivalent regions (GADM L2)
- 284.6 km²100.0% of basin
13 communes (GADM L5)Available for FRA, RWA
- Morcenx46.33 km²75% commune
- Arengosse41.63 km²66% commune
- Ygos-Saint-Saturnin31.58 km²54% commune
- Arjuzanx29.42 km²100% commune
- Villenave27.12 km²98% commune
- Garrosse26.24 km²100% commune
- Ousse-Suzan24.39 km²100% commune
- Saint-Yaguen18.86 km²49% commune
- Rion-des-Landes15.47 km²13% commune
- Beylongue11.63 km²31% commune
- Sindères6.30 km²31% commune
- Saint-Martin-d'Oney3.21 km²9% commune
- Geloux2.46 km²5% commune
3 intersecting protected areas
Arjuzanx
IUCN IVNational Nature Reserve
22.06 km² overlap
Site d'Arjuzanx
IUCN Not ReportedSpecial Protection Area (Birds Directive)
21.23 km² overlap
Réseau hydrographique des affluents de la Midouze
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
5.41 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
3 378 distinct species · 83 781 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 44 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 Bès : 36 espèces dont 2 patrimoniales (LR IUCN CR/EN/VU) reliées par 119 interactions GloBI sur 5 types (connectance 12.6%, filtre Serrano α=0.2). 8 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°
12,8°C
Annual rain
1 107mm
Moisture idx (CMI)
0,13
Runoff
597mm/an
PET
967mm
AET
744mm
Mean slope
1,2°
Water table
113cm
Forest
95%
Crops
2%
Urban
0%
Protected
8%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)