Dr inż. Bogdan Bąk

Prof. dr hab. inż. Leszek Łabędzki

Verification of 10- and 20-day forecasts of the standardized precipitation index SPI

In the paper the verification of precipitation condition forecasts are presented. The forecasts have been developed in the monitoring system of water deficiency and excess conducted by the Institute of Technology and Life Sciences. Analyses were performed for seven meteorological stations within Kujawy Region, south-eastern part of Pomerania and western Wielkopolska in the months of the growing season (April-September) in 2013-2014. Actual precipitation deficit and surplus and their 10-day and 20-day forecasts were determined every 10/11 days for the period of 30/31 days using the standardized precipitation index SPI. Two verification criteria were adopted: the difference between actual and predicted SPI cannot be greater than 0.5 and the agreement of the precipitation category classes. The verifiability is determined as the relative frequency of the forecasts meeting these criteria. It was found that the average verifiability of 10-day forecasts in the study area was high and equal to 80% for the assumed criteria. In the case of 20-day forecasts average verifiability was respectively 52%. ...

Prof. dr hab. inż. Leszek Łabędzki

Dr inż. Bogdan Bąk

Method of indicato-based assessment and classification of soil moisture on permanent grassland in Poland

Assessment of soil moisture conditions on permanent grassland in Poland is made within the nationwide monitoring of water deficit and surplus in agriculture performed by Institute of Technology and Life Sciences from 2013. Soil moisture index SMI is used to categorize soil moisture in the end of each 10-day period during the vegetation period (April-September), using the original classification proposed by the authors. SMI enables the comparison of moisture conditions in soils with different water retention and the objective evaluation of soil drought and water excess. Assessment is made for grassland in wet, moist, periodically dry and dry habitats in 2013-2014. In wet and moist habitats soil moisture was in the optimal range for grassland plants and meteorological conditions affected in small degree. In periodically and dry habitats soil moisture was more differentiated and was affected by actual meteorological conditions greater. Soil droughts dominated. ...