WPŁYW PROJEKTOWANEJ KOPALNI KRUSZYWA IŃSKO NA ŚRODOWISKO WÓD PODZIEMNYCH I POWIERZCHNIOWYCH – MODEL MATEMATYCZNY

Abstract

INFLUENCE OF THE SAND AND GRAVEL OPEN PIT AT IŃSKO (POLAND) ON WATER ENVIRONMENT – A NUMERICAL MODELAbstract. The Szczecin Mineral Raw Materials Pits Company Ltd is planning to build an open pit of sand and gravel close to Ińsko town. Rock extraction is planned without dewatering. There are conflicting opinions in the local community on the influence on the hydrology system in the vicinity of the open pit. The authors of the paper calculated influence of the open pit by a numerical modelling method.Twoaquifer are recognized in the research area. There is the unconfined aquifer comprising the outwash glacial sand and the confined aquifer under a glacial till layer.Asteady-state flow simulation was performed in MODFLOW Processing (PMWin ver. 5.3). The aquifer was simulated using the three model layers with a regular grid 50x50 m. Loss of water from the groundwater was evaluated by taking into account 1) increased evaporation after taking off the unsaturated zone, 2) loss of water from wet sand and gravel and 3) the amount of water taken for social purpose. The total loss of water was estimated at the amount of 65 ±10 m3/24h. This discharge was evenly distributed across the open pit area. The results of simulation provided information about the cone of depression.The cone of depression (isoline 0.3 m) did not reach the lake shore. The depression within the mine area was only 0.3 m, so it is not remarkable. Therefore there will be no influence of the open pit on water environment.