Advances in dynamics of groundwater circulation patterns

Abstract

As an essential part of hydrological cycle, groundwater circulation is a process including groundwater recharge, flow and discharge, which has been the primary research topic in hydrogeology.The spatial patterns of groundwater circulation are composed of different structure elements.There are two partitioning methods: the media structure determined from aquifer properties and the dynamic patterns determined according to the seepage field.A groundwater flow system (GFS) roles as a groundwater circulation cell within the concept of the dynamic patterns.In the last decade, significant advances have been achieved in the theory of GFSs, revealing groundwater circulation patterns in more comprehensive and deep ways.Studies on GFSs between parallel streams discovered that the top of water table is not the accurate position of groundwater divide.At the basin scale, the integrated impacts of the vale landform, precipitation infiltration rate, depth dependent permeability and basin thickness on the undulating shape of water table and groundwater circulation patterns were systematically investigated, with preliminary discovery on the evolution characteristics of dynamic patterns in periodicity and tendencies.Partitioning methods for three dimensional groundwater circulation cells were developed, according to fine-grained identification of paths or statistic analysis on residence times along a huge number of streamlines.For the hydrogeological effect, it has been found that the groundwater circulation patterns significantly influence the distribution of groundwater age.As an indication of hydraulic connection between recharge and discharge zones, groundwater circulation patterns play a key role in the geochemical processes at the basin scale and eco-hydrological processes at the catchment scale, which should be studied with more attentions on the dynamic and evolution behaviors of the three-dimensional groundwater circulation.

Keywords

• hydrological cycle
• groundwater flow system
• groundwater divide
• water table
• basin