HydroBASINS lev08 watershed · #4080039700
Bassin de 関川
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 7 administrative regions : Arao, Miyama, Nagasu, Nagomi, Nankan +2
Sub-basin area
223,2km²
Upstream area
223,2km²
Discharge
9,66m³/s
Mean elev.
49m
Administrative coverage
7 dept-equivalent regions (GADM L2)
- 75.2 km²33.7% of basin
- 59.0 km²26.4% of basin
- 34.3 km²15.4% of basin
- 22.1 km²9.9% of basin
- 19.9 km²8.9% of basin
- 3.1 km²1.4% of basin
- 0.7 km²0.3% of basin
11 intersecting protected areas
Shodai san
IUCN VPrefectural Natural Park
24.73 km² overlap
Ariake
IUCN IVPrefectural Wildlife Protection Area
13.14 km² overlap
Mitsukayama
IUCN IVPrefectural Wildlife Protection Area
5.99 km² overlap
Arao higata
IUCN IVNational Wildlife Protection Area
4.88 km² overlap
Common fishery right area
3.91 km² overlap
Common fishery right area
3.90 km² overlap
Amagiyama
IUCN IVPrefectural Wildlife Protection Area
3.12 km² overlap
Shodaisan
IUCN IVPrefectural Wildlife Protection Area
2.90 km² overlap
Yabe gawa
IUCN VPrefectural Natural Park
1.16 km² overlap
2 more protected areassorted by overlap area
Arao-higata
IUCN Not ReportedWetland of International Importance (Ramsar Site)
0.55 km² overlap
Otsuyama
IUCN IVPrefectural Wildlife Protection Area
0.46 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
424 distinct species · 2 668 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 27 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 関川 : 20 espèces dont 1 patrimoniale (LR IUCN CR/EN/VU) reliées par 47 interactions GloBI sur 2 types (connectance 12.4%, filtre Serrano α=0.2). 8 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°
16,2°C
Annual rain
1 836mm
Moisture idx (CMI)
0,39
Runoff
1 371mm/an
PET
1 126mm
AET
1 122mm
Mean slope
3,7°
Water table
132cm
Forest
18%
Crops
13%
Urban
53%
Protected
24%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)