The aim of this work was the analysis of the occurrence of drought, which was determined by the deficit of precipitation and the deficit of soil moisture in the time period 2015 till 2021 in the Orava region, in the comparison with the extent of damage caused by the drought and important biotic pests on the adult forests, which had been registered by the foresters of the Lesy SR, the state corporation. The Orava region was chosen because of the long-term spruce forests decline and the occurrence of more severe drought, which had been rare in the past there. The long-term soil water deficit can expressively weaken the forests, what was finally confirmed in our work. The biotic malign factors Ips typographus L., Pityogenes chalcographus L. and Armilaria sp. were chosen for their high multitudes and for their predisposition to continue in the process of the degradation of woods, as the secondary, respectively the tertiary malign factor beside the drought. The condition of forest vegetation has the long-term feedback to the bad availability of soil moisture, which depends on the specific species resistance to the drought stress. The ascertained results confirm the suitability of the chosen methodology for the drought monitoring, because its outputs are in good agreement with the reports of drought impacts by the end employers. The soil water deficit correlates with deficit of precipitation. It was registered, that the occurrence of important biotic pests in the dry periods is more frequent and the warnings and precautions are inevitable.

The drought is much discussed phenomena in the latest years, because of its more frequent occurrence and the stronger intensity. For this reason, the monitoring of dry conditions is very important. The Slovak Hydrometeorological Institute (SHMI) monitors the meteorological and soil drought since 2015, and then in 2017, the monitoring of the surface water level and monitoring of the water resources with the drought impacts on the agriculture and forestry was added in 2017. The products are public and freely available on the SHMI webpage. The monitoring aims on the evolution of climatic conditions regarding to the beginning, the development and intensity of drought. The monitoring of meteorological drought is updating on weekly basis and the additional product is the forecast of drought for following 10 days. The used indices are SPEI and SPI. Both indices are calculated using flowing window with accumulation period of 30 days. Nowadays, the monitoring is only for selected 41 meteorological stations, but it is planned to convert it to grid resolution 1 km and on daily basis. The monitoring of soil drought is produced on weekly basis in the cooperation with CzechGlobe, from Brno, Czech Republic. The soil data are computed by SoilClim model in 0.5x0.5 km grid. The one part of soil drought monitoring is the characterisation of drought impacts on local scale. Drought impacts are evaluated in forestry and agriculture by experts. The model results and the answers from questionnaire are annually summarized and compared themselves. In this case the cooperation among experts from various departments is inevitable.

<p>Weather conditions were quite remarkable in Slovakia during the whole year of 2020. In terms of annual mean temperature, year 2020 was very warm, with temperature very much above normal and deviations ranging mostly from +1.3 to +1.6 ° C from the normal 1981-2010 (in mountain regions even more than +1.7 ° C). With the exception of spring 2020, all other seasons were significantly above normal in terms of seasonal temperature, especially the winter 2019/2020. From the point of view of the amount of atmospheric precipitation, last year has mostly the above-normal precipitation. This was mainly due to the frequent occurrence of thunderstorm torrential rainfalls during the summer and due to the exceptionally above-normal precipitation in October, when extreme widespread rainfalls occurred in some regions of western and eastern Slovakia between 11 and 15 October. The second half of the year was thus significantly different from the point of view of the precipitation balance in comparison with the period from 10 March to approximately 15 May, when exceptionally dry conditions prevailed in Slovakia. The drought in Slovakia in year 2020 was dominant mostly in the spring, mainly in April and in the beginning of May. The lack of soil moisture was caused by the very low level of the snow cover in the previous winter months and the weather was also influenced by the long-term anticyclone in April 2020. This month was very dry in the major part of Slovakia and the extreme drought hit 24.3 % of the area of Slovakia. The unfavourable situation was registered in various regions by our reporters, in both the agricultural and forestry sectors. In summer the situation was stable and the severe drought didn´t occurred. In September the mild drought was only in the eastern part of Slovakia. October was humid in several regions. The severe and extreme soil drought in November was expressed in the first half of December in the north-western and middle part of Slovakia.</p><p> Key words: extreme drought, April 2020</p>