Presentation of IWA Groundwater Specialist Conference 8-10 September 2011, Belgrade, Serbia - Page 10

Đurić et al. (2011) presented the groundwater component of the International Tisza River Basin Management Plan (ITRBMP). The Plan integrates the issues on water quality and water quantity, land and water management, floods and drought. Groundwater bodies (GWBs) are important sources for public water supply, industry and agriculture in the Tisza River Basin. The countries in the region, with the exception of Romania, depend mainly on groundwater sources to meet their drinking water needs. Based on common agreed criteria, 85 GWBs were identified as of basin-wide importance, putting them in focus concerning pressure analysis, status assessment and implementation of measures in order to achieve good quantitative and chemical status. The main reasons for pollution in the Tisza River Basin are similar to the Danube River Basin, such as: water pollution caused by intensive agriculture and livestock breeding; insufficient municipal wastewater collection and treatment; inappropriate waste disposal sites; urban land use; insufficient wastewater treatment at industrial enterprises. To prevent pollution of groundwater bodies by hazardous substances from point source discharges liable to cause pollution, an effective regulatory framework has to be put in place prohibiting direct discharge of pollutants into groundwater and setting all necessary measures required to prevent significant losses of pollutants from technical installations. It is also necessary to prevent and/or reduce the impact of accidental pollution incidents. Illegal water abstraction and indirect abstraction by drainage may be a significant and specific problem in the Tisza River Basin concerning quantitative status. Implementation of appropriate controls of the abstraction of fresh surface water and groundwater and impoundment of fresh surface waters including a register or registers of water abstractions are foreseen as key measures for addressing poor quantitative status of groundwater bodies in the Tisza River Basin. Since the agriculture is one of the key activities causing significant alterations mainly through water abstractions, other measures (change in drainage systems, cessation of illegal abstractions, the use of crops with low water demand, as well as the application of water-saving irrigation technology), should also be applied in order to avoid groundwater depletion.

Results of the status assessment clearly show that contamination by nitrate and ammonium from diffuse sources is the main reason for the poor status of groundwater bodies in the Tisza River Basin.

Cisotto et al. (2011) applied a Water Balance Tool (set of computational techniques and models) for studying the phreatic aquifer located in the High Veneto Plain - HVP (North East Italy). The water table in this aquifer has decreased during the last decade due to over-exploitation, a trend that will continue due to the negative impacts of climatic changes on groundwater. In order to reconstruct, by means of geostatistical methods, the aquifer's geometries and minimum, medium and maximum volumes (water-holding capacity related to water banking), and to monitor its time-space evolution, a specific Water Balance Tool has been implemented. This predictive tool is based upon the hydrodynamics schematisation of the HVP system, subdivided into distinct hydro-geological sectors; it has been built using Mike SHE software as a finite element model combining numerical algorithms with the implemented GIS database. In order to obtain data needed for the Balance Tool and the reconstruction of the HVP aquifer, a geodatabase has been set up; it includes hydrological data (rainfall, snow, temperature, humidity, wind, hydrometric levels, etc), land use, agronomic and hydro-geological data (water levels, pumping rates, total depths, permeability, etc.). In particular, groundwater raw data acquired since the '70s and coming from some 300 boreholes located in the area. The data have been acquired with both traditional (manual) and automatic (datalogger) methods, during measurement campaigns.

The water level grids for the extreme hydro-geological conditions have been computed considering the minimum and the maximum absolute values for all the geodatabase boreholes. They have allowed for the definition of 3D geometries of underground volume, to characterise its evolution in the last years and to quantify the effective amount of water reserves (once the aquifer's effective porosity is evaluated). The total aquifer is presented, even if in an elementary way, as a homogeneous volume superimposed on the bedrock surface. After the required model implementation with all the potential ins and outs, the groundwater simulations for the selected period were completed. The model set up has been validated with particular reference to water table statistic elaborations and average water balance information from previous studies, in order to assess the hydro-geological sector conditions.