HydroBASINS lev08 watershed · #2080048900
Bassin de River Itchen
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 : NA
Sub-basin area
488,2km²
Upstream area
488,3km²
Discharge
7,46m³/s
Mean elev.
94m
Administrative coverage
2 dept-equivalent regions (GADM L2)
- NAEngland · United Kingdom472.4 km²96.4% of basin
- NAEngland · United Kingdom17.1 km²3.5% of basin
25 intersecting protected areas
South Downs
IUCN VNational Park
157.73 km² overlap
River Itchen
IUCN IVSite of Special Scientific Interest
7.49 km² overlap
River Itchen
IUCN Not ReportedEmerald Network
3.04 km² overlap
Hinton Ampner
IUCN VNature Reserve
1.07 km² overlap
Solent and Dorset Coast
IUCN Not ReportedEmerald Network
0.95 km² overlap
Solent and Dorset Coast
IUCN Not ReportedSpecial Protection Area (Birds Directive)
0.95 km² overlap
Crab Wood
IUCN IVSite of Special Scientific Interest
0.73 km² overlap
Magdalen Hill Down
IUCN VNature Reserve
0.48 km² overlap
St. Catherine's Hill
IUCN IVSite of Special Scientific Interest
0.43 km² overlap
16 more protected areassorted by overlap area
Crab Wood
IUCN IVLocal Nature Reserve
0.38 km² overlap
Solent and Southampton Water
IUCN Not ReportedWetland of International Importance (Ramsar Site)
0.37 km² overlap
Site of Special Scientific Interest
0.37 km² overlap
Solent and Southampton Water
IUCN Not ReportedEmerald Network
0.37 km² overlap
Solent and Southampton Water
IUCN Not ReportedMarine Protected Area (OSPAR)
0.34 km² overlap
Alresford Pond
IUCN IVSite of Special Scientific Interest
0.30 km² overlap
Trodds Copse
IUCN IVSite of Special Scientific Interest
0.26 km² overlap
Valley Park Woodlands
IUCN IVLocal Nature Reserve
0.25 km² overlap
Shawford Down
IUCN IVLocal Nature Reserve
0.20 km² overlap
Peartree Green
IUCN IVLocal Nature Reserve
0.18 km² overlap
Cheesefoot Head
IUCN IVSite of Special Scientific Interest
0.13 km² overlap
Chessel Bay
IUCN IVLocal Nature Reserve
0.13 km² overlap
Hocombe Mead
IUCN IVLocal Nature Reserve
0.08 km² overlap
Moorgreen Meadows
IUCN IVSite of Special Scientific Interest
0.07 km² overlap
Yew Hill
IUCN IVNature Reserve
0.06 km² overlap
Ratlake Meadows
IUCN IVSite of Special Scientific Interest
0.04 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
7 298 distinct species · 683 741 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 31 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 River Itchen : 26 espèces dont 1 patrimoniale (LR IUCN CR/EN/VU) reliées par 60 interactions GloBI sur 2 types (connectance 12.9%, filtre Serrano α=0.2). 5 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°
9,9°C
Annual rain
798mm
Moisture idx (CMI)
0,12
Runoff
449mm/an
PET
704mm
AET
534mm
Mean slope
2,5°
Water table
128cm
Forest
1%
Crops
55%
Urban
20%
Protected
33%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)