Ruisseau· 6 segments
Havelse Å
Crosses 3 administrative regions : Frederikssund, Halsnæs, Hillerød
Total length
22km
Max discharge
1,8m³/s
Max Strahler
2
Segments matched
6
River geography3 admin regions · 0 communes
3 administrative regions crossed (GADM L2)
- HillerødHovedstaden · Denmark19.8 kmin this dpt
- HalsnæsHovedstaden · Denmark3.3 kmin this dpt
- FrederikssundHovedstaden · Denmark1.0 kmin this dpt
11 intersecting protected areas
Roskilde Fjord og Jaegerspris Nordskov
IUCN Not ReportedBaltic Sea Protected Area (HELCOM)
Roskilde Fjord
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
Roskilde Fjord, Kattinge Vig og Kattinge Sø
IUCN Not ReportedSpecial Protection Area (Birds Directive)
Hillerød Kommune public
IUCN IV§3 protected habitats (all lakes, bogs, streams, heaths and meadows etc.)
Halsnæs Kommune public
IUCN IV§3 protected habitats (all lakes, bogs, streams, heaths and meadows etc.)
Frederikssund Kommune private
IUCN Not Assigned§3 protected habitats (all lakes, bogs, streams, heaths and meadows etc.)
Hillerød Kommune private
IUCN Not Assigned§3 protected habitats (all lakes, bogs, streams, heaths and meadows etc.)
Frederikssund Kommune public
IUCN IV§3 protected habitats (all lakes, bogs, streams, heaths and meadows etc.)
Halsnæs Kommune private
IUCN Not Assigned§3 protected habitats (all lakes, bogs, streams, heaths and meadows etc.)
2 more protected areassorted by area
Freerslev hegn
IUCN Not ReportedSite of Community Importance (Habitats Directive)
Strø Bjerge
IUCN IIIProtected by conservation order, excl. Church surroundings
1 page = 1 named river (aggregation of 6 HydroRIVERS v10 segments). Spatial join cached after first hit.
Species present
1 179 distinct species · 15 079 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 23 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 Havelse Å : 12 espèces dont 1 patrimoniale (LR IUCN CR/EN/VU) reliées par 82 interactions GloBI sur 5 types (connectance 29.7%, 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).
Hydrology (HydroRIVERS v10)
Total length
22km
Max discharge
1,8m³/s
Max Strahler
2
Segments matched
6
HydroRIVERS v1.0 (Lehner et al. 2019) aggregated by name + main_riv → 1 entity = 1 named river.