HydroBASINS lev08 watershed · #7080041630
Bassin de The Big Swamp
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 2 administrative regions : Richmond, Westmoreland
Sub-basin area
186,4km²
Upstream area
186,4km²
Discharge
2,43m³/s
Mean elev.
38m
Administrative coverage
2 dept-equivalent regions (GADM L2)
- Richmond109.5 km²58.7% of basin
- Westmoreland76.7 km²41.1% of basin
3 intersecting protected areas
Marine Protected Area
6.77 km² overlap
Rappahannock River Valley
IUCN IVNational Wildlife Refuge
4.21 km² overlap
National Wildlife Refuge
3.54 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
822 distinct species · 33 565 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 39 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 The Big Swamp : 31 espèces reliées par 75 interactions GloBI sur 4 types (connectance 9.6%, filtre Serrano α=0.2). 9 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 073mm
Moisture idx (CMI)
-0,08
Runoff
400mm/an
PET
1 169mm
AET
868mm
Mean slope
1,5°
Water table
76cm
Forest
97%
Crops
27%
Urban
0%
Protected
2%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)