HydroBASINS lev08 watershed · #1081647410
Bassin de Holrivier
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 1 administrative regions : West Coast
Sub-basin area
252,4km²
Upstream area
17 077,1km²
Discharge
21,84m³/s
Mean elev.
121m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 2 basins
- Bassin de Varsrivier1026 km²
- Bassin de Soutrivier815 km²
1 dept-equivalent regions (GADM L2)
- 252.2 km²100.0% of basin
1 intersecting protected areas
Knersvlakte Nature Reserve
IUCN Not ReportedNature Reserve
81.17 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
434 distinct species · 1 464 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 40 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 Holrivier : 32 espèces reliées par 34 interactions GloBI sur 4 types (connectance 4.4%, filtre Serrano α=0.2). 8 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°
18,6°C
Annual rain
168mm
Moisture idx (CMI)
-0,89
Runoff
16mm/an
PET
1 549mm
AET
142mm
Mean slope
2,4°
Water table
800cm
Forest
0%
Crops
4%
Urban
0%
Protected
0%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)