WATER RETENTION POSSIBILITIES IN SOILS - HUNGARIAN PART OF TISZA-RIVER BASIN

In many regions of Europe (among others in Hungary) agricultural production has been affected by droughts over the past decades. Global Water Partnership (GWP) Central and Eastern Europe (CEE) wanted to supported European countries in developing of an early warning system, which consists of monitoring, prediction and combine national drought policies. In order to use risk assessment – in which prevention of drought is emphasized - available water content calculation of watershed should be prepared for drought impacted areas. The aim of our study was to create a high-resolution, trans - border database, which takes into account the most important water regime properties of soils and it can be uniformly used in other countries of Tisza River Basin. Based on traditional soil maps, a soil database was created, where soil water content - in 2m layer depth of soil - can be estimated for different horizons and for different soil types. First of all, digital soil maps of different countries were adjusted to WRB (World Reference Base for Soil Resources), and calculation mapping was worked out for the total area of the Tisza River Basin. After allocations of the soil layers, physical limit values of soils were estimated by using pedo-transfer functions. Water storage capacity and available water content were determined by the depth of the impermeable layer. Finally, spatial queries were carried out in the Tisza River Basin and in units of administration. These data were integrated into a geographic information system, in which the data clearly showed that the impact of drought was more severe in extreme water management soils. In case of large-scale long-term droughts, local differences decreased the reliability of the calculations to a lesser degree. However, with further methodological development, the effect of these local differences can be reduced