HydroBASINS lev08 watershed · #4080558300
Bassin de 油川
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 : Kanuma, Katashina, Nikkō, Numata
Sub-basin area
264,3km²
Upstream area
264,3km²
Discharge
5,81m³/s
Mean elev.
1 321m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
4 dept-equivalent regions (GADM L2)
- 261.9 km²99.1% of basin
- 2.2 km²0.8% of basin
- 0.2 km²0.1% of basin
- 0.0 km²0.0% of basin
22 intersecting protected areas
Nikko
IUCN VNational Park
226.93 km² overlap
Nikko
IUCN IVPrefectural Wildlife Protection Area
141.16 km² overlap
Nikko Line
IUCN VGreen Corridor
81.98 km² overlap
Green Corridor
6.16 km² overlap
Oku-Nikko-shitsugen
IUCN IIWetland of International Importance (Ramsar Site)
2.62 km² overlap
Senjogahara Shitsugen
IUCN IVRare Population Protected Forest
1.77 km² overlap
Rare Population Protected Forest
0.99 km² overlap
Chanokidaira Urajiromomi
IUCN IVRare Population Protected Forest
0.76 km² overlap
Odashiro Shitsugen
IUCN IVRare Population Protected Forest
0.70 km² overlap
13 more protected areassorted by overlap area
Rare Population Protected Forest
0.57 km² overlap
National Natural Monument
0.49 km² overlap
Marunuma sugenuma
IUCN IVPrefectural Wildlife Protection Area
0.35 km² overlap
Rare Population Protected Forest
0.35 km² overlap
Kotoku Mizunara
IUCN IVRare Population Protected Forest
0.24 km² overlap
Osawa
IUCN IVPrefectural Wildlife Protection Area
0.23 km² overlap
Okukinu
IUCN IVBiocenosis Protected Forest
0.14 km² overlap
Kotoku Harunire
IUCN IVRare Population Protected Forest
0.13 km² overlap
Yutaki Mizunara Idenshigen
IUCN IVRare Population Protected Forest
0.13 km² overlap
Rare Population Protected Forest
0.13 km² overlap
Omanakoko Kometsuga
IUCN IVRare Population Protected Forest
0.12 km² overlap
Maenikko
IUCN VPrefectural Natural Park
0.06 km² overlap
Rare Population Protected Forest
0.04 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
2 441 distinct species · 25 358 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 37 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 油川 : 24 espèces reliées par 70 interactions GloBI sur 3 types (connectance 9.0%, filtre Serrano α=0.2). 16 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
2 118mm
Moisture idx (CMI)
0,63
Runoff
712mm/an
PET
766mm
AET
766mm
Mean slope
15,5°
Water table
453cm
Forest
39%
Crops
49%
Urban
7%
Protected
86%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)