Appliance of hydrodynamical model on groundwater source “Sava I” (Serbia): possibility of groundwater source protection

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

Dušan Polomčić¹, Veselin Dragišić¹, Miroslav Krmpotić¹

¹ Rudarsko-geološki fakultet Institut za hidrogeologiju, Beograd

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. These 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 hidrodinamical 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. Further analysis of groundwater source “Sava I” is performed in order to determine prevalency of sanitary protection zones nearby groundwater source. Partial tracking simulations is performed for time intersections of 50 and 200 days. Hydrodynamical model of groundwater source “Sava I” gave important parameters for conclusions making considering aquifer formed in it. The greatest contribution of derived analysis of groundwater source system is implementations of aquifer schematization, boundary term defining, quantified groundwater balance, and determining sanitary protection zones.

Key words: hydrodynamical model, water supply, groundwater sources, hydrogeology, sanitary protection zones.