Detailed hydrogeological studies are often necessary to assess the water balance of a watershed. Understanding the hydrogeological structures makes it possible to establish the watershed boundaries, to verify the congruence of the watershed hydrographic boundaries and the boundaries of the groundwater basin (Chapter 2), to locate the aquifers at various depths, and to establish the relationship between these aquifers and the surface water. In reminder, the groundwater system is connected to the hydrological cycle by various processes: infiltration through the unsaturated zone, contribution to ground-water by percolation and leakage, evaporation from the unsaturated zone, and finally, groundwater outflow. Definitions: Aquifers and Types of Groundwater Hydrogeology is based on the analysis of two essential entities: the aquifer and the groundwater table: An is a permeable geological formation (soil or rock) with pores or cracks that interconnect and that are sufficiently large that water can freely circulate under the effect of gravity (examples: sands, gravels, fissured chalk, sandstone, etc). In this way, the aquifer constitutes a reservoir for the groundwater tables. The is all the water contained in the saturated zone of the

DOI link for Detailed hydrogeological studies are often necessary to assess the water balance of a watershed. Understanding the hydrogeological structures makes it possible to establish the watershed boundaries, to verify the congruence of the watershed hydrographic boundaries and the boundaries of the groundwater basin (Chapter 2), to locate the aquifers at various depths, and to establish the relationship between these aquifers and the surface water. In reminder, the groundwater system is connected to the hydrological cycle by various processes: infiltration through the unsaturated zone, contribution to ground-water by percolation and leakage, evaporation from the unsaturated zone, and finally, groundwater outflow. Definitions: Aquifers and Types of Groundwater Hydrogeology is based on the analysis of two essential entities: the aquifer and the groundwater table: An is a permeable geological formation (soil or rock) with pores or cracks that interconnect and that are sufficiently large that water can freely circulate under the effect of gravity (examples: sands, gravels, fissured chalk, sandstone, etc). In this way, the aquifer constitutes a reservoir for the groundwater tables. The is all the water contained in the saturated zone of the

Detailed hydrogeological studies are often necessary to assess the water balance of a watershed. Understanding the hydrogeological structures makes it possible to establish the watershed boundaries, to verify the congruence of the watershed hydrographic boundaries and the boundaries of the groundwater basin (Chapter 2), to locate the aquifers at various depths, and to establish the relationship between these aquifers and the surface water. In reminder, the groundwater system is connected to the hydrological cycle by various processes: infiltration through the unsaturated zone, contribution to ground-water by percolation and leakage, evaporation from the unsaturated zone, and finally, groundwater outflow. Definitions: Aquifers and Types of Groundwater Hydrogeology is based on the analysis of two essential entities: the aquifer and the groundwater table: An is a permeable geological formation (soil or rock) with pores or cracks that interconnect and that are sufficiently large that water can freely circulate under the effect of gravity (examples: sands, gravels, fissured chalk, sandstone, etc). In this way, the aquifer constitutes a reservoir for the groundwater tables. The is all the water contained in the saturated zone of the