HydroBASINS lev08 watershed · #2080033500
Bassin de Seutelven
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 8 administrative regions : Fredrikstad, Hvaler, Kraakeroey, Onsoey, Rolvsoey +3
Sub-basin area
339,7km²
Upstream area
339,7km²
Discharge
1,57m³/s
Mean elev.
28m
Administrative coverage
8 dept-equivalent regions (GADM L2)
- 108.2 km²31.7% of basin
- 88.6 km²25.9% of basin
- 46.5 km²13.6% of basin
- 21.3 km²6.2% of basin
- 18.5 km²5.4% of basin
- 9.8 km²2.9% of basin
- 1.9 km²0.6% of basin
- 0.7 km²0.2% of basin
30 intersecting protected areas
Ytre Hvaler
IUCN Not ReportedNational Park
22.72 km² overlap
Hvaler
IUCN Not ReportedEmerald Network
22.72 km² overlap
Ytre Hvaler
IUCN Not ReportedMarine Protected Area (OSPAR)
11.55 km² overlap
Kråkerøy-skjærgården
IUCN Not ReportedEmerald Network
3.33 km² overlap
Kråkerøy-skjærgården
IUCN IaNature Reserve
3.33 km² overlap
Rauerfjorden
IUCN Not ReportedMarine Protected Area
2.92 km² overlap
Skinnerflo
IUCN Not ReportedEmerald Network
1.76 km² overlap
Skinnerflo
IUCN IaNature Reserve
1.76 km² overlap
Kurefjorden
IUCN IaWetland of International Importance (Ramsar Site)
1.30 km² overlap
21 more protected areassorted by overlap area
Kurefjorden
IUCN Not ReportedEmerald Network
1.30 km² overlap
Kurefjorden
IUCN IaNature Reserve
1.30 km² overlap
Rauer
IUCN IaNature Reserve
0.97 km² overlap
Kråkstadfjorden
IUCN IaNature Reserve
0.74 km² overlap
Kråkstadfjorden
IUCN Not ReportedEmerald Network
0.74 km² overlap
Jerndalsfjellet
IUCN IaNature Reserve
0.50 km² overlap
Søndre Missingen
IUCN IaNature Reserve
0.40 km² overlap
Skjæløysundet
IUCN IaNature Reserve
0.40 km² overlap
Skårakilen
IUCN Not ReportedEmerald Network
0.38 km² overlap
Skårakilen
IUCN IaNature Reserve
0.37 km² overlap
Fuglevikbukta
IUCN IaNature Reserve
0.35 km² overlap
Lerdalen
IUCN IaNature Reserve
0.20 km² overlap
Verkenslund
IUCN IVHabitat management area
0.17 km² overlap
Rauerkalven
IUCN IaNature Reserve
0.14 km² overlap
Fjellsbergtangen
IUCN IaNature Reserve
0.13 km² overlap
Grindskjær
IUCN IVWildlife Conservation Area
0.13 km² overlap
Ilemyr
IUCN IaNature Reserve
0.12 km² overlap
Stordamsmyra
IUCN Not ReportedEmerald Network
0.10 km² overlap
Stordamsmyra
IUCN IaNature Reserve
0.10 km² overlap
Mærrapanna
IUCN IaNature Reserve
0.10 km² overlap
Garntangen
IUCN IaNature Reserve
0.10 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
10 330 distinct species · 725 848 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 33 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 Seutelven : 25 espèces dont 2 patrimoniales (LR IUCN CR/EN/VU) reliées par 90 interactions GloBI sur 3 types (connectance 15.1%, filtre Serrano α=0.2). 10 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°
7,0°C
Annual rain
746mm
Moisture idx (CMI)
0,34
Runoff
554mm/an
PET
492mm
AET
416mm
Mean slope
3,0°
Water table
158cm
Forest
72%
Crops
29%
Urban
7%
Protected
10%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)