eng Science and Education Publishing American Journal of Applied Mathematics and Statistics 2328-7292 2017-11-29 5 5 159 163 10.12691/ajams-5-5-1 AJAMS2017551 article Effect of Evaporation or Infiltration on the Free Surface of Groundwater in Certain Problems of Underground Hydromechanics E. N. Bereslavskii eduber@mail.ru 1 St. Petersburg State University for Civil Aviation, St. Petersburg, Russia Within the framework of the theory of plane steady filtration of an incompressible fluid according to Darcy's law, two limiting schemes modeling the filtration flows under the Joukowski tongue through a soil massive spread over an impermeable foundation or strongly permeable confined water bearing horizon are considered. http://pubs.sciepub.com/ajams/5/5/1/ajams-5-5-1.pdf filtration infiltrations evaporation groundwater free surface tongue of Zhukovsky Polubarinova-Cochina's method complex velocity conformal mappings Fuchsian equation