HydroBASINS lev08 watershed · #2080033570
Bassin de Alna
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 6 administrative regions : Jevnaker, Lunner, Nittedal, Oslo, Ringerike +1
Sub-basin area
305,2km²
Upstream area
305,2km²
Discharge
4,94m³/s
Mean elev.
337m
Administrative coverage
6 dept-equivalent regions (GADM L2)
- 231.6 km²75.5% of basin
- 23.9 km²7.8% of basin
- 22.8 km²7.4% of basin
- 20.2 km²6.6% of basin
- 7.6 km²2.5% of basin
- 0.7 km²0.2% of basin
17 intersecting protected areas
Maridalen og Mellomkollen
IUCN Not ReportedEmerald Network
30.51 km² overlap
Maridalen
IUCN VProtected Landscape
27.31 km² overlap
Spålen-Katnosa
IUCN IaNature Reserve
19.13 km² overlap
Spålen-Katnosa
IUCN Not ReportedEmerald Network
19.13 km² overlap
Mellomkollen
IUCN IaNature Reserve
3.19 km² overlap
Lillomarka
IUCN IaNature Reserve
3.11 km² overlap
Blankvann og Lørensetertjern
IUCN Not ReportedEmerald Network
1.91 km² overlap
Blankvann
IUCN VProtected Landscape
1.56 km² overlap
Røverkollen
IUCN IaNature Reserve
1.34 km² overlap
8 more protected areassorted by overlap area
Slattumsrøa
IUCN IaNature Reserve
0.97 km² overlap
Langvassbrenna
IUCN IaNature Reserve
0.82 km² overlap
Østensjøvannet
IUCN IaNature Reserve
0.53 km² overlap
Lørensetertjern
IUCN IaNature Reserve
0.26 km² overlap
Karusspytten
IUCN IaNature Reserve
0.06 km² overlap
Blankvann
IUCN IVProtected Landscape
0.03 km² overlap
Linderud Gård
IUCN Not ReportedBotanical Protection of Species
0.02 km² overlap
Årvollåsen
IUCN IIINatural Monument
0.00 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
12 617 distinct species · 573 126 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 Alna : 25 espèces dont 1 patrimoniale (LR IUCN CR/EN/VU) reliées par 98 interactions GloBI sur 5 types (connectance 14.7%, filtre Serrano α=0.2). 12 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°
4,1°C
Annual rain
792mm
Moisture idx (CMI)
0,32
Runoff
585mm/an
PET
535mm
AET
453mm
Mean slope
6,8°
Water table
356cm
Forest
72%
Crops
6%
Urban
27%
Protected
17%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)