Appliance Of Hydrodynamical Model On Groundwater Source “Sava I”

APPLIANCE OF HYDRODYNAMICAL MODEL ON GROUNDWATER SOURCE “SAVA I” (SERBIA): POSSIBILITY OF ENLARGEMENT GROUNDWATER SOURCE

Dušan Polomčić¹, Veselin Dragišić¹, Miroslav Krmpotić¹, Vladimir Živanović¹

¹ Faculty of mining and geology, Belgrade

ABSTRACT: Groundwater source “Sava I” is used for water supplying of Ruma commune in Serbia. The latest explorations gave realistic foundation for exploitation regime simulation and for sanitary protection zones determination all around the groundwater source. Mentioned simulations are obtained by using hydrodynamical model that relies in this specific case on 3D groundwater flow simulation. Groundwater source “Sava I” model creating is carried out from the very beginning: from basic interpretation of input data, shematization of porous medium, flow field and terms of streaming, to model forming and measurements. In selection of basic model parameters, multilayer model with possibility of automatic flow field change that is dependent of groundwater flow conditions is produced. In hydrodinamical model of groundwater source “Sava I” following boundary conditions are applied: boundary with defined potential (piesometric head), river boundary condition, efective infiltration as residuum of infiltration by precipitation and evapotranspiration, and boundary condition with defined inflow. Among surface streams on terrain we can find river Sava and channel Jarčina. It is evident that river Sava has a dominant role on groundwater level in groundwater source while impact of pumping is bond for narrow zones within groundwater source “Sava I”. This is product of extraordinary good permeability characteristics of porous media and presence of river Sava that has very intensive hydraulic connection with groundwater of wide area of source “Sava I”. Groundwater flow in the model is calculated and simulated as real flow into confined or unconfined aquifer, in every field of diskretization separately. In measurements process of model for verification of obtained results, registered levels in observed wells are used. In analysis of groundwater balance for time period in which simulation of groundwater regime on investigation area is performed, dominant role has inflow from river Sava’s water (92.80%) unlike channel Jarčina with only 3.70%; infiltration by precipitation and inflow into groundwater source from east and south are almost negligible. The simulation of enlargement of the source „Sava I“ made for real conditions which planed in closely future. By this estimated, two new wells with 20 l/s each were simulated. The prognoses were computed for transient flow with time diskretization of one month for one year period.

Key words: hydrodynamical model, water supply, groundwater sources, hydrogeology, possibility of enlargement of groundwater sources.