In the paper, the agricultural drought was defined as at least the 7-days constant period when the reserve of easily accesible water in the root zone is depleted. Calculations based on meteorological data 1996–2005 from Mochełek (near Bydgoszcz) brought the assessment of beginnings of droughts and their classification in regard of duration. The assumptions of balance method for irri-gation forecast were taken into account. Two types of soil (compact and pervi-ous) and five cultivated plants (spring wheat and barley, faba bean, potato, maize) were taken into consideration. Results of the studies confirmed that within 10-year period in Bydgoszcz surroundings 8–16 agricultural droughts occured (depending on the soil and cul-tivated plant type). The majority of droughts were moderate (series of 7–13 days with accesible water deplation). Severe (series of 14–20 days) and very severe droughts (series over 20 days) made 24% of the total number of drought spells. The qualitative assessment of severe and very severe agricultural droughts pre-sents a good compatibility to particular indexes used for atmospheric drought evaluation. ...
The system of drought monitoring has been performed by the Institute of Technology and Life Sciences in Bydgoszcz since 2008. Meteorological drought is evaluated using SPI (Standardized Precipitation Index) and agricultural drought - using CDI (Crop Drought Index). CDI is calculated with the linear regression relationships between CDI and SPI. Prediction of meteorological and agricultural drought is made in the 10-day periods, using the forecast of precipitation obtained from WetterOnline.The verifiability of SPI forecast was high (80-100%). The verifiability of CDI depended on crop type and soil water retention - it ranged from 50 to 100%. The differences in drought classes were determined only in several cases.Monitoring and estimation of drought are the base of decision and activi-ties making in agricultural production, water management in the rural areas, irri-gation and estimation of yield losses. ...
This article presents the analysis of atmospheric circulation conditions per-taining to agricultural droughts in the Podkarpackie Province during the growing season (1901-2000). The following resource materials have been used: daily ca-lendar of atmospheric circulation types elaborated by T. Niedzwiedz for southern Poland, and growing season meteorological calendar elaborated by T. Zawora for southern Poland for the following monthly periods. The author had to determine the frequency of atmospheric circulation types for months which have been recognized by agricultural specialists as too dry (due to precipitation deficit). Drought hazard may be expressed by the following ratio: frequency of occurrence of a given circulation type during drought conditions to general frequency of circulation types. This method enabled to present detailed results. Firstly during the growing season the anticyclonic circulation type - advection of air from southwest - occurs 1,38 more frequently than the general frequency of this particular circulation type (SEa). The situation is similar for types Sa and Ea (1,35 and 1,33 respectively). When we examine the remaining values we can notice that the fre-quency coefficient for anticyclonic ridge (Ka) is equal to 1,21, whilst for anticyclonic situation with advection of air from northeast (NEa), and for central anticyclonic situation (Ca) ...
Since 2012 Institute of Technology and Life Sciences has lead a national agro-meteorological monitoring in rural areas. The system provides current and forecasted information on the status and impact of water shortages in selected, representative of agricultural ecosystems and estimates potential reduction of crop yield. Required meteorological data are provided by a network of automatic stations located in 13 regions on Polish territory. Weather forecasts, necessary to develop predictions of water shortages in the next 10 and 20 days, come from the meteorological service of MeteoGroup Poland. Monitoring of water deficits and their consequences is carried out on using an indicator method. Precipitation conditions are monitored using standardized precipitation index SPI, soil moisture - soil moisture index SMI, the deficit of water for crops - agricultural drought index CDI and the potential reduction of final yield - yield reduction ratio YR. Results of the monitoring and forecasts are presented as tables and maps in the Internet. ...
