Assessment of spatial and temporal variability of rainfain in Central Poland in the year 2013-2015

In Polish climatic conditions rainfall constitutes the main source of water for vegetation. The climate of Poland is characterized by high temporal and spatial variation. The total amount and seasonal distribution of precipitation show significant variability. The aim of the study was to analyze spatial changeability of rainfall in Central Poland. Data concerning rainfall were collected during the vegetative seasons of April - October in years 2013 - 2015. Analysis of the results confirms the observation which states that there is a great spatial variability of sum of precipitation, its maximum amount and intensity as well as the length of dry and rainy periods. Significant differences were observed between the stations located very close to each other. On the basis of obtained results it is stated that the rainfall must be measured directly on the area for which the water balance is to be estimated. ...

CHANGES OF SOIL MOISTURE IN THE UNSATURATED ZONE DURING RAINLESS PERIODS IN THE MARTEW FOREST AREA

The paper presents changes of volumetric soil moisture during rainless periods in the area covered by the sixty year-old pine stand. The analysed area is located in the Tuczno Forest District, the Martew Forest Area in the north-western part of Poland. The calculations were based on the measurements of volumetric soil moisture at seven different depths below the ground level (to the depth of about 7 m). A set of probes was installed in the unsaturated zone for moisture measuring, using TDR method (Decagon Devices Em5b-ECH2O), in order to calculate volumetric soil moisture changes in the unsaturated zone. Volumetric soil moisture measurements used in this work were calculated at daily intervals during rainless periods in the years 2013-2016. The variability of volumetric soil moisture during the rainless periods was registered only at the shallowest level (0.85 m below the ground level). On deeper levels over relatively long (more than 20 days) rainless periods these changes are negligible. The Authors suggested the Weibull equation to describe the changes of volumetric soil moisture at shallow levels during the rainless periods. ...