HydroBASINS lev08 watershed · #4080580740
Bassin de 赤平川
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 6 administrative regions : Chichibu, Kamikawa, Kanna, Minano, Ogano +1
Sub-basin area
249,6km²
Upstream area
249,8km²
Discharge
3,92m³/s
Mean elev.
556m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
6 dept-equivalent regions (GADM L2)
- 161.2 km²64.6% of basin
- 73.5 km²29.4% of basin
- 8.0 km²3.2% of basin
- 5.3 km²2.1% of basin
- KamikawaSaitama · Japan1.3 km²0.5% of basin
- 0.3 km²0.1% of basin
19 intersecting protected areas
Nishi chichibu
IUCN VPrefectural Natural Park
92.44 km² overlap
Ryokami
IUCN VPrefectural Natural Park
54.89 km² overlap
Ryokamisan
IUCN IVPrefectural Wildlife Protection Area
16.95 km² overlap
Chichibu tama kai
IUCN VNational Park
12.69 km² overlap
Kannonyama
IUCN IVPrefectural Wildlife Protection Area
11.72 km² overlap
Nishi chichibu
IUCN IVPrefectural Wildlife Protection Area
5.57 km² overlap
Nagatoro tamayodo
IUCN VPrefectural Natural Park
3.09 km² overlap
Jobu
IUCN VPrefectural Natural Park
2.82 km² overlap
Ogano machi takimae
IUCN VPrefectural Nature Conservation Area
2.61 km² overlap
10 more protected areassorted by overlap area
Ryokami
IUCN IVPrefectural Wildlife Protection Area
1.59 km² overlap
Ogano machi onouchi
IUCN VPrefectural Nature Conservation Area
1.10 km² overlap
Buko
IUCN VPrefectural Natural Park
0.70 km² overlap
Ogano machi hannya
IUCN VPrefectural Nature Conservation Area
0.15 km² overlap
Kanoyama
IUCN IVPrefectural Wildlife Protection Area
0.12 km² overlap
Ogano machi yobake
IUCN VPrefectural Nature Conservation Area
0.12 km² overlap
Chichibu shi tanaka yama
IUCN VPrefectural Nature Conservation Area
0.10 km² overlap
Ryokami shogakko
IUCN IVPrefectural Wildlife Protection Area
0.10 km² overlap
Chichibu shi onagata
IUCN VPrefectural Nature Conservation Area
0.04 km² overlap
Chichibu shi shirasuna
IUCN VPrefectural Nature Conservation Area
0.03 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
1 824 distinct species · 8 800 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 赤平川 : 30 espèces reliées par 28 interactions GloBI sur 4 types (connectance 5.3%, filtre Serrano α=0.2). 3 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°
11,7°C
Annual rain
1 268mm
Moisture idx (CMI)
0,19
Runoff
582mm/an
PET
1 025mm
AET
955mm
Mean slope
17,4°
Water table
583cm
Forest
93%
Crops
6%
Urban
5%
Protected
71%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)