HydroBASINS lev08 watershed · #4080050150
Bassin de Valukki Aaru 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 17 administrative regions across 2 countries : Delft, Island South (Velanai), Islands North (Kayts), Jaffna, Kandawali +12
Sub-basin area
1 390,7km²
Upstream area
1 390,7km²
Discharge
4,77m³/s
Mean elev.
6m
Administrative coverage
17 dept-equivalent regions (GADM L2)
- 227.0 km²16.4% of basin
- 178.8 km²12.9% of basin
- Vadamaradchy EastJaffna · Sri Lanka153.0 km²11.0% of basin
- Valikamam EastJaffna · Sri Lanka118.6 km²8.6% of basin
- Island South (Velanai)Jaffna · Sri Lanka93.2 km²6.7% of basin
- Vadamaradchi South-WestJaffna · Sri Lanka86.7 km²6.3% of basin
- Valikamam WestJaffna · Sri Lanka75.4 km²5.4% of basin
- Valikamam NorthJaffna · Sri Lanka53.7 km²3.9% of basin
9 moreFull L2 list
- Valikamam South-West49.7 km² · 3.6%
- Delft49.4 km² · 3.6%
- Vadamaradchy North39.2 km² · 2.8%
- Valikamam South36.2 km² · 2.6%
- Islands North (Kayts)32.0 km² · 2.3%
- Nallur31.7 km² · 2.3%
- Jaffna14.0 km² · 1.0%
- Kandawali0.1 km² · 0.0%
- Ramanathapuram0.0 km² · 0.0%
5 intersecting protected areas
Nagarkovil NR
IUCN IbNature Reserve
78.36 km² overlap
Chundikulam NP
IUCN IVNational Park
59.14 km² overlap
Delft NP
IUCN IINational Park
17.98 km² overlap
Pallai
IUCN IbReserved Forest
4.25 km² overlap
Parititivu Island
IUCN IVSanctuary
0.11 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
1 729 distinct species · 24 626 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 25 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 Valukki Aaru River : 18 espèces reliées par 37 interactions GloBI sur 4 types (connectance 12.3%, 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°
27,8°C
Annual rain
1 281mm
Moisture idx (CMI)
-0,01
Runoff
445mm/an
PET
1 298mm
AET
788mm
Mean slope
0,2°
Water table
27cm
Forest
5%
Crops
8%
Urban
27%
Protected
3%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)