Information entropy evolution of groundwater flow system affected by human activity

Groundwater flow system has characteristics of dissipative structure, and the groundwater flow system evolution could be described with the groundwater flow system information entropy variation. The groundwater flow system information entropies of Shijiazhuang City between 1960 and 2005 have been calculated using the field entropy methodology, and the results show that, the entropies of groundwater flow system have a decreasing trend through the research period, and four stages can be divided based on the groundwater flow system entropy variation as following: entropy steady period (1960-1965), entropy decreasing period (1965-1980), entropy increasing period (1980-1995) and secondary entropy decreasing period (1995-2005); understanding the major and significant driving forces to change patterns of groundwater levels is essential to groundwater management new method of grey correlation analysis have been presented, and the results show that, the grey correlation grade between groundwater flow system information entropies and precipitation series is γ01 = 0.749, the grey correlation grade between groundwater flow system information entropies and groundwater extraction series is γ02 = 0.814, as the groundwater extraction is the main driving force of groundwater flow system entropies variation.