HydroBASINS lev08 watershed · #2080257170
Bassin de Hålandsbekken
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 4 administrative regions : Arendal, Birkenes, Froland, Grimstad
Sub-basin area
203,3km²
Upstream area
203,3km²
Discharge
6,04m³/s
Mean elev.
177m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
4 dept-equivalent regions (GADM L2)
- 160.6 km²78.6% of basin
- 17.1 km²8.4% of basin
- 16.6 km²8.1% of basin
- 10.1 km²4.9% of basin
9 intersecting protected areas
Skiftenes
IUCN IaNature Reserve
1.25 km² overlap
Bjorsund
IUCN IaNature Reserve
0.72 km² overlap
Skiftenes
IUCN Not ReportedEmerald Network
0.71 km² overlap
Rossefjellet
IUCN IaNature Reserve
0.66 km² overlap
Lauvåsen
IUCN Not ReportedEmerald Network
0.23 km² overlap
Lauvåsen
IUCN IaNature Reserve
0.23 km² overlap
Bjellandshaugane
IUCN Not ReportedEmerald Network
0.20 km² overlap
Bjellandshaugane
IUCN IaNature Reserve
0.20 km² overlap
Porsmyr
IUCN IaNature Reserve
0.13 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
3 946 distinct species · 45 453 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 35 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 Hålandsbekken : 29 espèces reliées par 85 interactions GloBI sur 5 types (connectance 14.3%, filtre Serrano α=0.2). 6 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°
6,3°C
Annual rain
1 211mm
Moisture idx (CMI)
0,61
Runoff
970mm/an
PET
467mm
AET
444mm
Mean slope
6,3°
Water table
262cm
Forest
90%
Crops
6%
Urban
1%
Protected
1%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)