HydroBASINS lev08 watershed · #2080585850
Bassin de Fiume Merse
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 : Grosseto, Siena
Sub-basin area
673,9km²
Upstream area
674km²
Discharge
7,27m³/s
Mean elev.
369m
Administrative coverage
Hydrographic chain
▼ Drains into
▲ Receives from 0 basins
Source / headwater (no upstream basin)
2 dept-equivalent regions (GADM L2)
- 525.1 km²77.8% of basin
- 150.0 km²22.2% of basin
13 intersecting protected areas
Alta Val di Merse
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
94.90 km² overlap
Montagnola Senese
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
73.70 km² overlap
Val di Farma
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
69.72 km² overlap
Basso Merse
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
36.51 km² overlap
Riserva naturale Alto Merse
IUCN IVRegional/Provincial Nature Reserve
19.66 km² overlap
Riserva naturale Basso Merse
IUCN IVRegional/Provincial Nature Reserve
13.10 km² overlap
Riserva naturale Tocchi
IUCN IaState Nature Reserve
10.29 km² overlap
Riserva naturale Farma
IUCN IVRegional/Provincial Nature Reserve
8.12 km² overlap
Riserva naturale Cornocchia
IUCN IVState Nature Reserve
6.15 km² overlap
4 more protected areassorted by overlap area
Riserva naturale La Pietra
IUCN IVRegional/Provincial Nature Reserve
5.25 km² overlap
Poggi di Prata
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
2.51 km² overlap
Riserva naturale Palazzo
IUCN IVState Nature Reserve
1.90 km² overlap
Riserva naturale Belagaio
IUCN IVState Nature Reserve
1.35 km² overlap
Computed live · GADM 4.1 × HydroBASINS lev08 × WDPA · cached after first hit.
Species present
3 422 distinct species · 59 258 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 43 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 Fiume Merse : 30 espèces dont 2 patrimoniales (LR IUCN CR/EN/VU) reliées par 103 interactions GloBI sur 5 types (connectance 10.9%, filtre Serrano α=0.2). 14 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°
13,5°C
Annual rain
731mm
Moisture idx (CMI)
-0,23
Runoff
340mm/an
PET
950mm
AET
606mm
Mean slope
7,9°
Water table
337cm
Forest
75%
Crops
11%
Urban
0%
Protected
10%
HydroATLAS BasinATLAS v10 (Linke et al. 2019) · HydroBASINS lev08 (Lehner & Grill 2013)