HydroBASINS lev08 watershed · #4080566690
Bassin de 吾妻川
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 : Higashiagatsuma, Karuizawa, Komoro, Kuni, Kusatsu +13
Sub-basin area
1 340,7km²
Upstream area
1 340,7km²
Discharge
25,95m³/s
Mean elev.
1 029m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
19 dept-equivalent regions (GADM L2)
- 329.8 km²24.6% of basin
- 252.6 km²18.8% of basin
- 226.3 km²16.9% of basin
- 197.7 km²14.7% of basin
- 131.0 km²9.8% of basin
- 72.0 km²5.4% of basin
- 57.0 km²4.2% of basin
- 53.5 km²4.0% of basin
29 intersecting protected areas
Joshinetsukogen
IUCN IINational Park
397.70 km² overlap
Asama
IUCN IVNational Wildlife Protection Area
89.92 km² overlap
Kusatsu
IUCN IVPrefectural Wildlife Protection Area
35.38 km² overlap
Shiga Highland
IUCN Not ApplicableUNESCO-MAB Biosphere Reserve
35.36 km² overlap
Ikaho
IUCN IVPrefectural Wildlife Protection Area
15.22 km² overlap
Yoshigadaira Wetlands
IUCN IIWetland of International Importance (Ramsar Site)
8.51 km² overlap
Mikuni Line
IUCN VGreen Corridor
7.32 km² overlap
Onogaminokuchi
IUCN IVPrefectural Wildlife Protection Area
3.12 km² overlap
Saburyuyama Shuhen
IUCN IbForest Ecosystem Reserve
2.26 km² overlap
20 more protected areassorted by overlap area
Yunomaru rengetsutsuji gunraku
IUCN IIINational Natural Monument
2.24 km² overlap
Nozori
IUCN IVPrefectural Wildlife Protection Area
1.96 km² overlap
Minakami
IUCN Not ApplicableUNESCO-MAB Biosphere Reserve
1.80 km² overlap
Asamayama
IUCN IVBiocenosis Protected Forest
1.40 km² overlap
Shirosato ikomochi
IUCN IVPrefectural Wildlife Protection Area
1.20 km² overlap
KARUIZAWA KOGEN GOLF CLUB
IUCN Not ApplicableOECM
1.17 km² overlap
Harunasan
IUCN IVPrefectural Wildlife Protection Area
0.87 km² overlap
Hoshi
IUCN IVPrefectural Wildlife Protection Area
0.73 km² overlap
Kurofuyama Karamatsu
IUCN IVRare Population Protected Forest
0.46 km² overlap
Saburuyama
IUCN IVPrefectural Wildlife Protection Area
0.42 km² overlap
Manza Karamatsu
IUCN IVRare Population Protected Forest
0.24 km² overlap
Tonohara
IUCN IVPrefectural Wildlife Protection Area
0.18 km² overlap
Yonago
IUCN IVRare Population Protected Forest
0.16 km² overlap
Azuma
IUCN IVPrefectural Wildlife Protection Area
0.14 km² overlap
Takai
IUCN IVPrefectural Wildlife Protection Area
0.13 km² overlap
Hanamagariyama
IUCN IVPrefectural Wildlife Protection Area
0.11 km² overlap
Oryojino mori
IUCN VPrefectural Nature Conservation Area
0.10 km² overlap
Shiga kogen
IUCN IVPrefectural Wildlife Protection Area
0.09 km² overlap
National Natural Monument
0.06 km² overlap
Hoshi Kurobe
IUCN IVRare Population Protected Forest
0.01 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
3 144 distinct species · 18 271 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 31 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 吾妻川 : 21 espèces dont 1 patrimoniale (LR IUCN CR/EN/VU) reliées par 50 interactions GloBI sur 5 types (connectance 10.1%, filtre Serrano α=0.2). 11 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°
8,2°C
Annual rain
1 520mm
Moisture idx (CMI)
0,40
Runoff
820mm/an
PET
882mm
AET
866mm
Mean slope
12,6°
Water table
421cm
Forest
81%
Crops
15%
Urban
3%
Protected
33%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)