Assessment of Meteorological Drought Trends in a Selected Coastal Basin Area in Poland-A Case Study

The aim of this study is to investigate the patterns and trends of drought occurrence in the northern part of Poland on the example of the Leba river basin in the years 1956-2015. The study of meteorological drought was conducted on the basis of the Standardized Precipitation Index (SPI) on the scale of 1, 3, 6, 9, and 12 months. Annual precipitation totals did not show significant changes in the analyzed period, except for the station in Wejherowo, which is characterized by a significant increasing trend. The analysis of the long term of the variability average annual air temperature showed its statistically significant increase in the analyzed area at the rate of about 0.2 & DEG;C per decade. During the analyzed period, 14 to 84 meteorological droughts were identified, with durations ranging from 200 to 300 months. As the period of accumulating values of SPI, the number of droughts decreased, while their total duration increased. Most droughts were mild in nature, while extreme droughts accounted for between 5.2% and 10.7% of the duration. Drought intensification was shown only for SPI-1 in February and March in Wierzchucino station. On the other hand, a decreasing trend in SPI values was noted during longer periods of accumulation (SPI-6, 9, and 12).

Automated summary

This study aims to investigate the patterns and trends of drought occurrence in the northern part of Poland based on the Leba river basin data from 1956 to 2015. The Standardized Precipitation Index (SPI) was used to analyze meteorological drought on different time scales. The results showed that annual precipitation did not change significantly except for a station in Wejherowo with an increasing trend. The average annual air temperature had a statistically significant increase, and a total of 14 to 84 droughts were identified during the analyzed period. Most droughts were mild, but extreme droughts accounted for a small percentage of the duration. Drought intensification was observed in February and March for SPI-1 in Wierzchucino, while a decreasing trend was noted for longer accumulation periods (SPI-6, 9, and 12).