Meteorological and agricultural drought indices used in drought monitoring in Poland: a review

In the article, a brief review is presented of the definition of meteorological and agricultural droughts, drought indices and the operational systems of monitoring droughts in Poland. Drought is a widespread and frequent disaster which occurs more often within humid climate zones. Meteorological drought is the result of deficiencies in precipitation. Agricultural drought is an effect of various characteristics of meteorological and hydrological drought in agriculture comprising the reduction of evapotranspiration, soil water deficits, and reduced crop yield. Drought indicators are the common measures for drought assessment. The paper contains an inventory of drought measures (indicators) that are applied to evaluate meteorological and agricultural drought in Poland. For meteorological drought monitoring and the assessment of its intensity, four different indices have been used in Poland: relative precipitation index (RPI), effective drought index (EDI), standardised precipitation index (SPI) and climatic water balance (CWB). Agricultural drought is monitored by soil moisture index (SMI), agricultural drought index (CDI) and the potential reduction of final yield (yield reduction ratio YR). The working drought monitoring systems give information for the whole country or for a specific region but they are directed to some specific drought analyses. Four different drought monitoring systems have been under operation in Poland since 2005. The Institute of Meteorology and Water Management (IMGW) conducts the system called “POSUCH@”. The Institute of Soil Science and Plant Cultivation conducts the agricultural drought monitoring system. The Institute of Technology and Life Sciences (ITP) has developed two systems: the regional drought monitoring system in the Kujawy region and the nationwide system of monitoring and forecasting water deficit and surplus in agriculture.