HydroBASINS lev08 watershed · #4080028830
Bassin de Vanjiyar River
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 3 administrative regions : Karaikal, Nagappattinam, Thiruvarur
Sub-basin area
340,8km²
Upstream area
340,8km²
Discharge
0,94m³/s
Mean elev.
7m
Administrative coverage
3 dept-equivalent regions (GADM L2)
- Nagappattinam257.3 km²75.8% of basin
- KaraikalPuducherry · India40.2 km²11.8% of basin
- Thiruvarur34.5 km²10.2% of basin
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
636 distinct species · 9 604 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 Vanjiyar River : 24 espèces dont 2 patrimoniales (LR IUCN CR/EN/VU) reliées par 38 interactions GloBI sur 3 types (connectance 8.2%, filtre Serrano α=0.2). 7 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°
28,5°C
Annual rain
1 224mm
Moisture idx (CMI)
-0,24
Runoff
479mm/an
PET
1 614mm
AET
829mm
Mean slope
0,0°
Water table
7cm
Forest
2%
Crops
73%
Urban
18%
Protected
0%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)