HydroBASINS lev08 watershed · #4080043080
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 8 administrative regions : Iiyama, Iizuna, Itoigawa, Jōetsu, Myōkō +3
Sub-basin area
803,4km²
Upstream area
803,5km²
Discharge
52,1m³/s
Mean elev.
635m
Administrative coverage
8 dept-equivalent regions (GADM L2)
- 430.9 km²53.6% of basin
- 275.9 km²34.3% of basin
- 67.9 km²8.4% of basin
- 14.6 km²1.8% of basin
- 6.9 km²0.9% of basin
- 6.2 km²0.8% of basin
- 1.3 km²0.2% of basin
- 0.0 km²0.0% of basin
19 intersecting protected areas
Myokotogakushirenzan
IUCN IINational Park
191.94 km² overlap
Myokosan
IUCN IVPrefectural Wildlife Protection Area
86.45 km² overlap
Kubiki
IUCN VPrefectural Natural Park
30.33 km² overlap
Hiuchiyama
IUCN IVPrefectural Wildlife Protection Area
20.96 km² overlap
Togakushiyama
IUCN IVPrefectural Wildlife Protection Area
8.16 km² overlap
Nojiriko
IUCN IVPrefectural Wildlife Protection Area
6.50 km² overlap
Hiuchiyamashuhen Xxx
IUCN IVRare Population Protected Forest
3.92 km² overlap
Kasugayama
IUCN IVPrefectural Wildlife Protection Area
0.84 km² overlap
Imoriike
IUCN IVPrefectural Wildlife Protection Area
0.81 km² overlap
10 more protected areassorted by overlap area
Nojiri
IUCN IVPrefectural Wildlife Protection Area
0.75 km² overlap
Nakakubiki kaigan
IUCN IVPrefectural Wildlife Protection Area
0.74 km² overlap
Takadajoseki
IUCN IVPrefectural Wildlife Protection Area
0.62 km² overlap
Yamabe
IUCN IVPrefectural Wildlife Protection Area
0.55 km² overlap
Hanareyama
IUCN IVPrefectural Wildlife Protection Area
0.13 km² overlap
Amakazari・Tenguharayama
IUCN IVBiocenosis Protected Forest
0.10 km² overlap
Togakushiyama
IUCN IVBiocenosis Protected Forest
0.08 km² overlap
Okususobana
IUCN IVPrefectural Wildlife Protection Area
0.07 km² overlap
Common fishery right area
0.06 km² overlap
Amakazari and Togakushi
IUCN VGreen Corridor
0.00 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
1 892 distinct species · 9 181 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 30 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 : 24 espèces reliées par 37 interactions GloBI sur 5 types (connectance 8.0%, filtre Serrano α=0.2). 7 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°
10,1°C
Annual rain
1 851mm
Moisture idx (CMI)
0,49
Runoff
1 657mm/an
PET
914mm
AET
883mm
Mean slope
11,3°
Water table
295cm
Forest
67%
Crops
21%
Urban
12%
Protected
28%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)