HydroBASINS lev08 watershed · #2080033540
Bassin de Såna
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 11 administrative regions : Frogn, Hobøl, Moss, Nesodden, Oppegård +6
Sub-basin area
635,7km²
Upstream area
635,7km²
Discharge
1,89m³/s
Mean elev.
91m
Administrative coverage
11 dept-equivalent regions (GADM L2)
- 125.7 km²19.7% of basin
- 104.1 km²16.3% of basin
- 78.1 km²12.2% of basin
- 63.4 km²9.9% of basin
- 52.9 km²8.3% of basin
- 52.4 km²8.2% of basin
- 37.6 km²5.9% of basin
- 35.5 km²5.6% of basin
30 intersecting protected areas
Eldøya-Sletter
IUCN Not ReportedEmerald Network
6.05 km² overlap
Eldøya-Sletter
IUCN IVProtected Landscape
5.49 km² overlap
Værne Kloster
IUCN VProtected Landscape
5.11 km² overlap
Søndre Jeløy
IUCN Not ReportedEmerald Network
3.93 km² overlap
Søndre Jeløy
IUCN VProtected Landscape
3.62 km² overlap
Svartskog
IUCN Not ReportedEmerald Network
2.29 km² overlap
Svartskog
IUCN VProtected Landscape
1.92 km² overlap
Ødemørk
IUCN IaNature Reserve
1.65 km² overlap
Vardåsen
IUCN IaNature Reserve
0.89 km² overlap
21 more protected areassorted by overlap area
Nærevann
IUCN Not ReportedEmerald Network
0.83 km² overlap
Nærevann
IUCN IaNature Reserve
0.83 km² overlap
Nordre Pollen
IUCN IaNature Reserve
0.81 km² overlap
Østmarka
IUCN IINational Park
0.67 km² overlap
Rambergåsen
IUCN IaNature Reserve
0.64 km² overlap
Trolldalen
IUCN IaNature Reserve
0.59 km² overlap
Kurefjorden
IUCN IaNature Reserve
0.52 km² overlap
Kurefjorden
IUCN IaWetland of International Importance (Ramsar Site)
0.52 km² overlap
Kurefjorden
IUCN Not ReportedEmerald Network
0.52 km² overlap
Malmøya
IUCN Not ReportedEmerald Network
0.50 km² overlap
Malmøya og Malmøykalven
IUCN IaNature Reserve
0.50 km² overlap
Pollevann
IUCN IaNature Reserve
0.44 km² overlap
Østensjøvann
IUCN IaNature Reserve
0.44 km² overlap
Rødsåsen
IUCN IaNature Reserve
0.43 km² overlap
Midtsjøvann
IUCN IaNature Reserve
0.43 km² overlap
Delingsdalen
IUCN IaNature Reserve
0.39 km² overlap
Ekebergskråningen
IUCN Not ReportedEmerald Network
0.37 km² overlap
Ekebergskråningen
IUCN IaNature Reserve
0.35 km² overlap
Reierskogen
IUCN IaNature Reserve
0.28 km² overlap
Eldøya
IUCN IaNature Reserve
0.26 km² overlap
Rambergbukta
IUCN IaNature Reserve
0.24 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
18 039 distinct species · 1 581 054 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 34 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 Såna : 26 espèces dont 1 patrimoniale (LR IUCN CR/EN/VU) reliées par 81 interactions GloBI sur 3 types (connectance 14.4%, 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°
6,1°C
Annual rain
762mm
Moisture idx (CMI)
0,30
Runoff
571mm/an
PET
533mm
AET
442mm
Mean slope
4,2°
Water table
285cm
Forest
67%
Crops
14%
Urban
23%
Protected
4%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)