This paper examines efficiency of building drainage system on the territory of Pancevo rit (south Banat). In this case, the research incorporates hydro-technical and economic indicators on which building of drainage systems depends. Analysed area covers over 80 000 ha of agricultural and building land. Hydro-technical solution offers 6 possible alternatives that can be applied in stages. For these alternatives total surface in risk of flood (ha) and total defended surface (ha) have been estimated. In addition to this, potential investments into building (€) and consumption of energy for powering pumping station (kWh) have been calculated for each alternative. Operational expenses of these systems include expenses of energy, expenses of maintenance and expenses of management. Expenses per defended ha, depending on the chosen alternative, amount from 45 to 110 €/ha. The effect of drainage for yield increase was calculated using differential calculation method on the example of corn. The difference in this case (using drainage - without use of drainage) amounted 1.6 t/ha in average or 3.5 million € per year for the entire area. Long-term effects by these systems are especially significant. Neto present value for the period exploitation of the system for 30 years and a discount rate of 6% was about 15,1 million €. Internal rate of return for the same input data was 10,3%,which is more compared to the basic discount rate. Risk assessment using the sensitive analysis showed that such projects are more sensitive on the reduction in income from the project that on increased investment in the construction of the system. Considering the fact that the efficiency of drainage was examined using hydro-technical and economic indicators, the order of building of particular alternative was determined using multi-criteria optimization. In this case, method Electra 2 has been chosen. The input data matrix contained 6 variants and 6 criteria. One criterion regarding defended surface (ha) converged to maximum, while total investment (€), consumed energy (kWh), investment per defended ha (€/ha), operational expenses per defended ha (€/ha), expenses per defended ha (€/ha) to the minimum. The result of ranking coincides with hydro-technical analysis.

drainage, efficiency, variants, ranking

Presentation: oral