2. Study Area:
The Ain River has an oceanic hydrologic regime and drains a basin of about 3630 km2. It is located in the southern Jura Mountains, France. The length of the Ain River is about 200 km and it is the right bank tributary of the Rhône River. The lower part of the Ain River, which is located between the Allement dam and the confluence with the Rhône River, was taken for the study purpose. Figure 1 shows the location of the lower Ain river area. Along this section, the average channel width is about 60 m and the slope is about 1.3%. The mean annual discharge of the river, between 1959 to 2019, was evaluated as 120 m3/s at the measuring station of Chazey-sur-Ain. Most floods occur between October and March (probability of occurring flood discharge of 1200 m3/s, once in 10 years, at Chazey-sur-Ain) and summer is characterized by low flow conditions. Further detail about the study area is provided in the groundwater model section.