HydroBASINS lev08 watershed · #4080048930
Bassin de Polwatta Ganga
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 9 administrative regions : Akmeemana, Akuressa, Habaraduwa, Imaduwa, Malimbada +4
Sub-basin area
223,6km²
Upstream area
223,6km²
Discharge
10,07m³/s
Mean elev.
62m
Administrative coverage
9 dept-equivalent regions (GADM L2)
- 97.5 km²43.8% of basin
- 49.4 km²22.2% of basin
- 27.4 km²12.3% of basin
- 21.4 km²9.6% of basin
- 12.7 km²5.7% of basin
- 6.5 km²2.9% of basin
- 6.2 km²2.8% of basin
- 1.4 km²0.6% of basin
1 moreFull L2 list
- Habaraduwa0.0 km² · 0.0%
7 intersecting protected areas
Kottawa kombala
IUCN IaConservation Forest
3.47 km² overlap
Kudagalkanda
IUCN IbReserved Forest
2.36 km² overlap
Kanneliya-Dediyagala-Nakiyadeniya (KDN)
IUCN Not ApplicableUNESCO-MAB Biosphere Reserve
2.33 km² overlap
Pattaramoraketiya
IUCN IbReserved Forest
1.16 km² overlap
Nabadawamalandeniya
IUCN IbReserved Forest
0.51 km² overlap
Wellana
IUCN IbReserved Forest
0.18 km² overlap
Gallanda Kuttiya
IUCN IbReserved Forest
0.08 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
368 distinct species · 3 255 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 38 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 Polwatta Ganga : 34 espèces dont 4 patrimoniales (LR IUCN CR/EN/VU) reliées par 36 interactions GloBI sur 3 types (connectance 5.1%, filtre Serrano α=0.2). 4 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°
26,5°C
Annual rain
2 651mm
Moisture idx (CMI)
0,52
Runoff
1 338mm/an
PET
1 278mm
AET
1 257mm
Mean slope
5,7°
Water table
191cm
Forest
14%
Crops
67%
Urban
49%
Protected
1%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)