HydroBASINS lev08 watershed · #4080582840
Bassin de 荒川
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 19 administrative regions : Chichibu, Fukaya, Gyōda, Higashichichibu, Higashimatsuyama +14
Sub-basin area
417,9km²
Upstream area
1 220,6km²
Discharge
20,19m³/s
Mean elev.
118m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 2 basins
- Bassin de 荒川553 km²
- Bassin de 赤平川250 km²
19 dept-equivalent regions (GADM L2)
- 64.2 km²15.4% of basin
- 53.8 km²12.9% of basin
- 46.7 km²11.2% of basin
- 40.0 km²9.6% of basin
- 37.1 km²8.9% of basin
- 31.0 km²7.4% of basin
- 27.0 km²6.5% of basin
- HigashimatsuyamaSaitama · Japan26.5 km²6.3% of basin
20 intersecting protected areas
Nagatoro tamayodo
IUCN VPrefectural Natural Park
94.08 km² overlap
Hiki kyuryo
IUCN VPrefectural Natural Park
14.20 km² overlap
Namegawa
IUCN IVPrefectural Wildlife Protection Area
8.22 km² overlap
Orihara
IUCN IVPrefectural Wildlife Protection Area
7.50 km² overlap
Arakawa oaso
IUCN IVPrefectural Wildlife Protection Area
6.73 km² overlap
Nogami
IUCN IVPrefectural Wildlife Protection Area
2.99 km² overlap
Kitamoto
IUCN IVPrefectural Wildlife Protection Area
2.46 km² overlap
Akihara
IUCN IVPrefectural Wildlife Protection Area
0.94 km² overlap
Rissho daigaku-monjuji
IUCN IVPrefectural Wildlife Protection Area
0.93 km² overlap
11 more protected areassorted by overlap area
Kawamisegawara
IUCN IVPrefectural Wildlife Protection Area
0.74 km² overlap
Miyamae shogakko
IUCN IVPrefectural Wildlife Protection Area
0.63 km² overlap
Jobu
IUCN VPrefectural Natural Park
0.59 km² overlap
HondaWoods Minamiyorii Tsudoi no Sato
IUCN Not ApplicableOECM
0.26 km² overlap
Kawamoto
IUCN IVPrefectural Wildlife Protection Area
0.15 km² overlap
Obusuma chugakko
IUCN IVPrefectural Wildlife Protection Area
0.14 km² overlap
Ranzan machi sugiyama
IUCN VPrefectural Nature Conservation Area
0.12 km² overlap
Kumagaya shi onuma
IUCN VPrefectural Nature Conservation Area
0.09 km² overlap
Nagatoro daini shogakko
IUCN IVPrefectural Wildlife Protection Area
0.08 km² overlap
Misato
IUCN IVPrefectural Wildlife Protection Area
0.03 km² overlap
Ogawa genki plaza
IUCN IVPrefectural Wildlife Protection Area
0.02 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
2 144 distinct species · 16 859 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 36 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 荒川 : 23 espèces reliées par 77 interactions GloBI sur 5 types (connectance 10.4%, 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°
14,0°C
Annual rain
1 312mm
Moisture idx (CMI)
0,19
Runoff
514mm/an
PET
1 057mm
AET
984mm
Mean slope
4,3°
Water table
154cm
Forest
30%
Crops
8%
Urban
61%
Protected
31%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)