HydroBASINS lev08 watershed · #4080048910
Bassin de Nilwala 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 24 administrative regions : Akuressa, Athuraliya, Beliatta, Devinuwara, Dickwella +19
Sub-basin area
1 041,4km²
Upstream area
1 041,7km²
Discharge
44,74m³/s
Mean elev.
143m
Administrative coverage
24 dept-equivalent regions (GADM L2)
- 130.9 km²12.6% of basin
- 128.1 km²12.3% of basin
- 125.6 km²12.1% of basin
- 118.4 km²11.4% of basin
- 80.8 km²7.8% of basin
- 67.8 km²6.5% of basin
- 60.0 km²5.8% of basin
- 52.7 km²5.1% of basin
16 moreFull L2 list
- Malimbada46.9 km² · 4.5%
- Matara Four Gravets41.1 km² · 4.0%
- Katuwana36.1 km² · 3.5%
- Kirinda-Puhulwella32.9 km² · 3.2%
- Thawalama32.8 km² · 3.2%
- Devinuwara21.7 km² · 2.1%
- Neluwa13.6 km² · 1.3%
- Kolonna10.6 km² · 1.0%
- Hakmana9.3 km² · 0.9%
- Nagoda7.4 km² · 0.7%
- Okewela6.4 km² · 0.6%
- Weligama5.0 km² · 0.5%
- Welipitiya4.8 km² · 0.5%
- Dickwella2.3 km² · 0.2%
- Yakkalamulla1.6 km² · 0.2%
- Beliatta0.2 km² · 0.0%
23 intersecting protected areas
Kanneliya-Dediyagala-Nakiyadeniya (KDN)
IUCN Not ApplicableUNESCO-MAB Biosphere Reserve
61.63 km² overlap
Dediyagala
IUCN IbReserved Forest
37.29 km² overlap
Mulatiyana
IUCN IbReserved Forest
36.05 km² overlap
Diyadawa
IUCN IaConservation Forest
17.61 km² overlap
Ramalakanda
IUCN IbReserved Forest
17.12 km² overlap
Kanneliya
IUCN IbReserved Forest
14.50 km² overlap
Viharakele
IUCN IbReserved Forest
8.49 km² overlap
Masmullakele
IUCN IbReserved Forest
7.15 km² overlap
Nakiyadeniya
IUCN IaConservation Forest
6.15 km² overlap
14 more protected areassorted by overlap area
Panilkanda
IUCN IbReserved Forest
6.10 km² overlap
Dandeniya Aparakka
IUCN IbReserved Forest
5.88 km² overlap
Kakenadurekeke
IUCN IbReserved Forest
4.54 km² overlap
Oliyagankele
IUCN IbReserved Forest
4.37 km² overlap
Kanumuldeniya
IUCN IbReserved Forest
3.84 km² overlap
Kirinda Mahayaya
IUCN IbReserved Forest
3.47 km² overlap
Welihena
IUCN IbReserved Forest
3.37 km² overlap
Kiralakela
IUCN IVSanctuary
3.33 km² overlap
Badullakele
IUCN IbReserved Forest
1.80 km² overlap
Ulinduwewa
IUCN Not ReportedForest Reserve
1.05 km² overlap
Gallanda Kuttiya
IUCN IbReserved Forest
0.82 km² overlap
Wellana
IUCN IbReserved Forest
0.81 km² overlap
Kalubovitiyana
IUCN IaConservation Forest
0.23 km² overlap
Mapitakanda
IUCN IbReserved Forest
0.01 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
700 distinct species · 111 234 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 28 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 Nilwala Ganga : 22 espèces dont 2 patrimoniales (LR IUCN CR/EN/VU) reliées par 31 interactions GloBI sur 3 types (connectance 8.2%, filtre Serrano α=0.2). 6 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°
26,2°C
Annual rain
2 679mm
Moisture idx (CMI)
0,49
Runoff
1 270mm/an
PET
1 346mm
AET
1 331mm
Mean slope
7,2°
Water table
272cm
Forest
38%
Crops
62%
Urban
43%
Protected
18%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)