THE GROUNDWATER FLOW SYSTEM IN CHAHANTAOHAI ECOLOGICAL ENVIRONMENT IMPROVEMENT AREA, INNER MONGOLIA

The groundwater flow system in the Chahantaohai ecological environmental improvement area, Inner Mongolia is composed of Upper Pleistocene alluvium pore water flow subsystem (Q₃^al), Middle Pleistocene alluvium pore water flow subsystem (Q₂^al), basement pore water flow subsystem, Holocene eolian sand pore water flow subsystem (Q₄^eol) and Holocene alluvium pore water flow subsystem (Q₄^al). Among them, the major mining bed is Q₃^al. All the other subsystems are the recharge beds for Q₃^al. The Q₃^al, Q₄^eol and basement groundwater flow subsystems receive the influent seepage recharge from the meteoric water, and then discharge at the eastern edge of Q₃^al. In natural condition, the Q₃^al subsystem receives recharge from Yellow River during flood peak and overflow stages, while discharges to Yellow River in other seasons.