High?resolution spatiotemporal analysis of hydrologic connectivity in the historical floodplain of straightened lowland agricultural streams

In agricultural watersheds, human interventions such as channel straightening have disrupted the hydrologic connectivity between headwater streams and their riparian environment thus undermined ecological services provided by these small streams. Knowledge of immediate (shallow groundwater in historical floodplain on adjacent hillslopes) human-impacted settings is critical for understanding restoring hydrological systems but remains largely incomplete. The objective this research to investigate hydrogeomorphological conditions controlling straightened lowland Detailed measurements spatiotemporal variability groundwater-surface water interactions reaches, including abandoned meanders, hillslopes were obtained using a dense network piezometers at two sites St. Lawrence Lowlands (Quebec, Canada). Results show that complex mechanisms naturally meandering rivers also operate highly disturbed despite backfilling practices. pre-straightening configuration partly explains patterns piezometric fluctuations observed sites. apex meanders stands out focal area levels indicate pressure transfer may reflect flows from stream, hillslopes, surrounding floodplain. These unique field observations suggest should be promoted key elements restoration strategies