DROUGHT INTENSITY ON ARABLE LAND IN ROMANIA – PROCESSES AND TENDENCIES

Abstract

Drought is one of the factors which may determine land degradation by aridization occurence. Under drought conditions the soil productivity decreases with negative impact on socio-economic conditions. Over 60 % of arable land is affected by drought. In this paper drought risk is evaluated at country level, processes induced by its occurrence and tendencies in future time horizons. Drought intensity was evaluated by using different indicators. Values of Palfay index which was corrected by soil properties, relief and watertable showed that in the south and south-eastern part of the country there is a high intensity of drought. The aridity index showed that there is a high variability during the time. In dry years the highest semi-arid area affected by drought is located in south-eastern part and all the other plain areas under arable use are defined as sub-humid areas. The Bagnouls-Gaussen aridity index showed that the drought occurs mostly in south-eastern part of the country for the time period of 1961-1990. For the future time horizons (2011-2020, 2041-2050, 2071-2080) the drought intensity increases. Within the time horizon of 2041-2050 the predictions show that the entire south part of Romania will be affected by high drought intensity. The environmentally sensitive area to desertification index (ESAI) showed that most of the arable land is classified as critical. The cumulated annual water deficit, the active temperature annual sum over 4 °C, the active temperature annual sum over 10 °C and the number of days with drought increased in the period of 1991-2000, in comparison with 1961-1990 time interval, mostly in western and eastern parts of the country. The same tendency is predicted for the future time horizons. Climate changes lead also in changes of hybrid productivity. Thus, in case of maize, the predictions show that the lately hybrids has higher productivity than early and medium-early ones in the time horizon of 1991-2000 in the most important arable areas. For the future time horizons (2011-2020, 2041-2050) the early and medium-early hybrids are most productive.