Physico-chemical parameters of river water in Oir and its tributaries (Manche county - France)

The data consist of physico-chemical parameters of river water in Oir and its tributaries, collected since 2001. The parameters are water temperature (°C), hydrogen potential (pH), conductivity, turbidity, nitrates (NO3-), nitrites (NO2-), ammonium (NH4+) and ortophosphates (PO4 ---). This data is collected as part of the French Environmental Research Observatory (ERO) on Diadromous Fish in Coastal rivers (DiaPFC). ORE DiaPFC is a research infrastructure dedicated to the study of diadromous fish populations under the influence of anthropic pressure (e.g. agriculture) and environmental changes (e.g. climate). The river Oir is located at the southern edge of Normandy in the Manche county (latitude: from 48.6840 to 48.5985; longitude: from -1.2949 to -1.0994), it is a tributary of the river Sélune, a coastal river that flows into the Bay of Mont Saint-Michel. The river Oir is 21km long with a 85.4 km2 catchment area. The elevation ranges from 9 to 80 metres, the mean gradient is 1.1% and the mean discharge is 1.1m3/s. The geology of the catchment is characterised by sedimentary schists and metamorphic hornfels with granite inclusions, and land use is dominated by agricultural activities, e.g. crops and livestock.