HydroBASINS lev08 watershed · #4080536760
Bassin de 渋海川
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, Jōetsu, Kashiwazaki, Nagaoka, Ojiya +3
Sub-basin area
350,7km²
Upstream area
350,8km²
Discharge
22,08m³/s
Mean elev.
269m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
8 dept-equivalent regions (GADM L2)
- 177.6 km²50.6% of basin
- 133.0 km²37.9% of basin
- KashiwazakiNiigata · Japan17.6 km²5.0% of basin
- 14.1 km²4.0% of basin
- 7.8 km²2.2% of basin
- 0.6 km²0.2% of basin
- 0.1 km²0.0% of basin
- 0.0 km²0.0% of basin
6 intersecting protected areas
Matsunoyama
IUCN IVPrefectural Wildlife Protection Area
14.34 km² overlap
Nomi matsunoyama oike
IUCN VPrefectural Natural Park
9.93 km² overlap
Enmeijigahara
IUCN IVPrefectural Wildlife Protection Area
4.72 km² overlap
Nonomi
IUCN IVPrefectural Wildlife Protection Area
0.23 km² overlap
Hachikokusan
IUCN IVPrefectural Wildlife Protection Area
0.13 km² overlap
Asahi Castle Woodland
IUCN Not ApplicableOECM
0.03 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
651 distinct species · 3 792 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 渋海川 : 23 espèces reliées par 58 interactions GloBI sur 5 types (connectance 11.0%, filtre Serrano α=0.2). 10 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°
11,8°C
Annual rain
2 091mm
Moisture idx (CMI)
0,55
Runoff
1 854mm/an
PET
942mm
AET
921mm
Mean slope
10,0°
Water table
283cm
Forest
81%
Crops
7%
Urban
6%
Protected
6%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)