HydroBASINS lev08 watershed · #2080425450
Bassin de l'Helpe Majeure
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 across 2 countries : Hainaut, Nord
Sub-basin area
323,9km²
Upstream area
323,9km²
Discharge
3,68m³/s
Mean elev.
208m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
2 dept-equivalent regions (GADM L2)
- 217.5 km²66.9% of basin
- 107.5 km²33.1% of basin
36 communes (GADM L5)Available for FRA, RWA
- Trélon20.50 km²52% commune
- Felleries19.46 km²100% commune
- Eppe-Sauvage16.88 km²100% commune
- Liessies12.98 km²75% commune
- Saint-Hilaire-sur-Helpe12.28 km²78% commune
- Dompierre-sur-Helpe11.84 km²88% commune
- Avesnelles11.59 km²88% commune
- Sémeries10.52 km²75% commune
- Ramousies9.79 km²100% commune
- Sains-du-Nord8.70 km²56% commune
- Taisnières-en-Thiérache8.20 km²99% commune
- Wallers-en-Fagne7.75 km²100% commune
- Baives7.75 km²100% commune
- Bas-Lieu7.32 km²96% commune
- Moustier-en-Fagne6.87 km²100% commune
- Marbaix6.36 km²94% commune
- Flaumont-Waudrechies5.54 km²100% commune
- Ohain5.48 km²46% commune
- Haut-Lieu5.14 km²61% commune
- Clairfayts4.30 km²56% commune
- Willies4.12 km²100% commune
- Sars-Poteries2.98 km²39% commune
- Solre-le-Château2.27 km²17% commune
- Avesnes-sur-Helpe2.11 km²100% commune
- Noyelles-sur-Sambre1.89 km²30% commune
- Beugnies1.80 km²20% commune
- Petit-Fayt1.31 km²16% commune
- Saint-Aubin0.47 km²4% commune
- Rainsars0.46 km²8% commune
- Maroilles0.44 km²2% commune
- Dourlers0.22 km²2% commune
- Semousies0.10 km²4% commune
- Grand-Fayt0.07 km²1% commune
- Leval0.01 km²0% commune
- Monceau-Saint-Waast0.01 km²0% commune
- Lez-Fontaine0.00 km²0% commune
20 intersecting protected areas
Avesnois
IUCN VRegional Nature Park
217.92 km² overlap
Forêt, bocage, étangs de Thiérache
IUCN Not ReportedSpecial Protection Area (Birds Directive)
57.56 km² overlap
National park - core area
25.11 km² overlap
Special Areas of Conservation (Habitats Directive)
11.86 km² overlap
Bois de Vieux Sart et de Montbliart
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
9.69 km² overlap
Bois de Vieux Sart et de Montbliart
IUCN Not ReportedSpecial Protection Area (Birds Directive)
9.69 km² overlap
Bois Massart et forêts de Sivry-Rance
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
6.90 km² overlap
Bois Massart et forêts de Sivry-Rance
IUCN Not ReportedSpecial Protection Area (Birds Directive)
6.90 km² overlap
Forêts de Rance
IUCN Not ReportedSpecial Protection Area (Birds Directive)
6.83 km² overlap
11 more protected areassorted by overlap area
Forêts de Rance
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
6.83 km² overlap
Massifs forestiers entre Momignies et Chimay
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
3.49 km² overlap
Massifs forestiers entre Momignies et Chimay
IUCN Not ReportedSpecial Protection Area (Birds Directive)
3.49 km² overlap
La Fagne entre Bailièvre et Robechies
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
3.21 km² overlap
La Fagne entre Bailièvre et Robechies
IUCN Not ReportedSpecial Protection Area (Birds Directive)
3.21 km² overlap
rnr des monts de baives
IUCN IVLand acquired by a regional conservatory of natural areas
0.41 km² overlap
Monts De Baives
IUCN IVRegional Nature Reserve
0.19 km² overlap
Land acquired by a regional conservatory of natural areas
0.10 km² overlap
prairies d eppe sauvage
IUCN IVLand acquired by a regional conservatory of natural areas
0.03 km² overlap
prairies de la maresse
IUCN IVLand acquired by a regional conservatory of natural areas
0.02 km² overlap
Vallée de la Sambre
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
0.00 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
4 493 distinct species · 190 614 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 l'Helpe Majeure : 19 espèces reliées par 125 interactions GloBI sur 6 types (connectance 25.2%, filtre Serrano α=0.2). 13 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°
9,3°C
Annual rain
894mm
Moisture idx (CMI)
0,15
Runoff
350mm/an
PET
757mm
AET
595mm
Mean slope
2,4°
Water table
159cm
Forest
25%
Crops
14%
Urban
2%
Protected
67%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)