Seasonal and spatial variation in groundwater quality along the hillslope of an agricultural research catchment (Western France)

摘要: Shallow groundwater that develops on hillslopes is the main compartment in headwater catchments for flow and solute transport to rivers. Although spatial temporal variations its chemical composition are reported literature, there no coherent description of way these organized, nor an accepted conceptual model mechanism involved. On basis results from experimental hillslope, we propose a variation patterns discuss mechanisms We instrumented catchment with network 42 nested piezometers along 200 m hillslope monitored major anion frequently over 2-year period. The demonstrated (i) anionic water table fluctuation zone varied significantly compared deeper portions aquifer confirming this layer constitutes mixing new recharge old groundwater, (ii) parts exhibited seasonal structured hysteretic patterns, suggesting processes also occurred at greater depths (iii) were dampered upslope downslope, indicating increased influence lateral downslope. recommend generality observations be assessed different environments, as they can constitute set include hydrological models. Copyright © 2010 John Wiley & Sons, Ltd.