Ruisseau· 12 segments
L'Yerre
Crosses 3 administrative regions : Eure-et-Loir, Loir-et-Cher, Sarthe
Total length
52km
Max discharge
1,9m³/s
Max Strahler
2
Segments matched
12
River geography3 admin regions · 21 communes
3 administrative regions crossed (GADM L2)
- Eure-et-LoirCentre-Val de Loire · France61.1 kmin this dpt
- Loir-et-CherCentre-Val de Loire · France3.7 kmin this dpt
- SarthePays de la Loire · France0.2 kmin this dpt
21 communes (L5)For countries with L5
- Arrou13.86 km
- La Bazoche-Gouet11.53 km
- Saint-Pellerin9.39 km
- Lanneray8.24 km
- Saint-Hilaire-sur-Yerre4.35 km
- Saint-Denis-les-Ponts3.94 km
- Le Gault-Perche2.95 km
- Langey2.57 km
- Chapelle-Royale2.49 km
- Chapelle-Guillaume1.86 km
- Châtillon-en-Dunois1.54 km
- Courtalain1.18 km
- Le Poislay0.74 km
- Gréez-sur-Roc0.24 km
- Autheuil0.15 km
- Soizé0.00 km
- Douy0.00 km
- Montigny-le-Gannelon0.00 km
- Saint-Avit0.00 km
- Boisgasson0.00 km
- Saint-Ulphace0.00 km
3 intersecting protected areas
Perche
IUCN VRegional Nature Park
Vallée du Loir et affluents aux environs de Châteaudun
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
Cuesta cénomanienne du Perche d'Eure-et-Loir
IUCN Not ReportedSpecial Areas of Conservation (Habitats Directive)
1 page = 1 named river (aggregation of 12 HydroRIVERS v10 segments). Spatial join cached after first hit.
Species present
1 188 distinct species · 14 183 observations
Source: GBIF Occurrence snapshot 2026-05-01.
Ecological tissue
Sample of 37 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 L'Yerre : 32 espèces dont 1 patrimoniale (LR IUCN CR/EN/VU) reliées par 81 interactions GloBI sur 5 types (connectance 12.2%, filtre Serrano α=0.2). 5 bulles taxonomiques (cascade genre/famille GloBI, ≥3 espèces).
Comparaison sur la connectance du réseau local complet vs distribution nationale (toutes les communes françaises).
Hydrology (HydroRIVERS v10)
Total length
52km
Max discharge
1,9m³/s
Max Strahler
2
Segments matched
12
HydroRIVERS v1.0 (Lehner et al. 2019) aggregated by name + main_riv → 1 entity = 1 named river.