ADMS

The Institute of Soil Science and Plant Cultivation – State Research Institute, in accordance with an Act from the Minister of Agriculture and Rural Development has developed the climatic water balance for all 2478 Polish local districts and, on the basis of soil categories, calculated the current risk of agricultural drought for the following crops: grain maize and maize for silage, potato, sugar beet, hops, tobacco, ground vegetables, fruit shrubs and trees, and legumes.

In the eleventh reporting period, i.e. from July 11th to September 10th, 2016, IUNG-PIB stated no risk of agricultural drought conditions in Poland. The Climatic Water Balance values, which are the basis for assessing the risk of agricultural drought, are negative for the majority of areas. However, for the aforementioned crops the values are higher than critical.

In this reporting period the lowest Climatic Water Balance values have been recorded in the region between the three geographical areas: the Dobrzyńskie Lake District, the eastern part of the Wielkopolskie Lake District, and the north-western part of the Mazowiecka Lowland. The lowest Climatic Water Balance values in these areas range from -119 to -139 mm.

In the current sixty-day period, from July 11th to September 10th 2016, the Climatic Water Balance values in Poland have decreased, on average, by 5 mm in comparison to the previous reporting period.

The air temperature in July this year was higher by 1°C than the multiannual average in the vast majority of areas. The maximum variation of the monthly average was recorded in the area of Wrocław (2°C). July was warm in the whole country. In the majority of the Polish territory the recorded temperature ranged from 19°C to 20°C. Slightly lower temperature (18°C-19°C) was recorded in the Pomeranian and the Mazurskie Lake Districts, in the eastern part of the Północnopodlaska Lowland and in the Kielecka Upland. The lowest temperature was recorded in the Bytowskie Lake District and in the western part of the Mazurskie Lake District, where it ranged from 17°C to 18°C.

The temperature distribution in the first decade of August was similar to July. The lowest temperature, below 16.5°C, was recorded in the Pomeranian Lake District, in the south-west Sudetes and in the Tatra Mountains. It was warmer in the Mazurskie Lake District and in the Małopolska Upland (17.5°C-18°C). The highest temperature, above 19.5°C was recorded in the south-eastern part of the Lubelska Upland and in the Opolska Plain. In the rest of the country temperatures ranged from 18.5°C to 19.5°C.

The second decade of August was slightly colder. The lowest temperature, below 15°C was recorded in the Suwalskie Lake District, in the central part of the Północnopodlaska Lowland, in the Sudetes, the Beskids and the Tatra Mountains. The highest temperatures, from 16.5°C to more than 17.5°C occurred in the central part of the Silesian Lowland, in the Południowowielkopolska Lowland, in the Lubawskie Lake District, and in the Mazowiecka Lowland. In the vast majority of the country the air temperature ranged from 15°C to 16.5°C.

The third decade of August was definitely warmer in comparison to the previous one. The highest air temperature (19°C-20°C) was recorded in the Lubuskie and Wielkopolskie Lake Districts, and in the Silesian and Mazowiecka Lowlands. The lowest temperature occurred in the south of Poland. In the Sudetes, the Carpathians, the Sudetian Foreland and the Carpathian Foothills the temperature ranged from 16°C to 18°C. In the rest of the country it was higher, from 18°C to 19°C.

In the first decade of September the lowest temperature, below 16.5°C, was recorded in the Tatra Mountains, the Bieszczady Mountains, in the eastern part of the Mazurskie Lake District and in the northern part of the Białostocka Upland. The lowest temperature was recorded in the Silesian Lowland and in the western part of the Głubczycki Plateau. The temperatures between 16.5°C and 18.0°C were recorded in the Sudetes, the Beskids, and in the Mazurskie and the Pomeranian Lake Districts. Temperatures between 18°C and 19.5°C were recorded in the rest of the country.

Precipitation in July widely varied across the country, mainly due to the stormy character of rainfalls. The lowest precipitation (below 60 mm) occurred in the western parts of the Pomeranian Lake District and the Szczecińskie Coastland, in the Mazowiecka Lowland, the Silesian Lowland, and in the Tarnowski Plateau, constituting 80-100% of the multiannual norm. In the rest of the country precipitation ranged from 80 to 160 mm. In the area of Toruń and the Białostocka Upland precipitation ranging from 180 to 200 mm occurred (constituting 200-240% of the multiannual norm). The highest precipitation values (220-260 mm, and here and there exceeding 260 mm) were recorded in the southern part of the Krakowsko-Częstochowska Upland, in the Beskids and in the Tatra Mountains, constituting 220-240% of the multiannual norm.

In the first decade of August a highly diversified precipitation was recorded. Precipitation below 10 mm occurred in the Silesian Lowland and in the southern part of the Południowowielkopolska Lowland. In the majority of the country precipitation ranged from 20 to 40 mm. The highest values, between 40 and 80 mm, and here and there exceeding 80 mm were recorded in the Koszalińskie Coastland, the Beskids, the Tatra Mountains and in the Małopolska Upland.

The second decade of August was also characterised by great variations in precipitation values. In the vast majority of the country precipitation did not exceed 5 mm. Slightly higher values (20-40 mm) were recorded in the northern part of the Pomeranian Lake District and the Mazurskie Lake District, in the Lubuskie Lake District and in the Przemyskie Foothills. The highest precipitation values ranging from 40 to 60 mm were recorded in the Koszalińskie Coastland and in the Górowskie Uplands.

In the third decade of August the lowest precipitation, below 5 mm, occurred in the Myśliborskie Lake District and in the eastern part of Południowopodlaska Lowland. The highest values, exceeding 40 mm and here and there up to 80 mm, were recorded in the Koszalińskie Coastland, in the southern part of the Silesian Lowland, in the Karpackie Foothills and the Carpathians, in the eastern part of Małopolska Upland and in the southern part of the Lubelska Upland. In the rest of the country precipitation values ranged from 5 to 40 mm.

In the first decade of September the lowest precipitation, below 5 mm, was recorded in the southern part of the Mazurskie Lake District, in the northern part of the Mazowiecka Lowland, in the eastern and central parts of the Wielkopolskie Lake District, in the western part of Głubczycki Plateau and in the eastern part of the Trzebnickie Hills. The highest precipitation values, above 60 mm, were recorded in the Western Tatras. In the rest of the country precipitation values ranged from 5 to 60 mm.

It should be noted that in the current reporting period the air temperature during the day is relatively high in the whole country. However, the cooling of the surface at night results in the appearance of dew in the areas covered with vegetation. The dew continues until late morning and in some areas even until midday, providing water for those plants that are still in their vegetation period.

It should be also stated that, the presented results concerning the drought entail only the yield reduction by 20% at the local district level caused by water deficiency in the given year, in comparison to the yield obtained in the multiannual average weather conditions. The current water deficiency conditions cause yield reduction, due to low water reserves in the soil. The Climatic Water Balance valuesin many regions of the country approximate their critical amounts, however, do not reach the critical level. The result is that in the current reporting period the average yield reduction by 20% due to drought conditions in local districts where the Climatic Water Balance values are low, has not been exceeded.

Report prepared by:

Dr hab. Andrzej Doroszewski, prof. nadzw.

Dr hab. Rafał Pudełko

Dr Katarzyna Żyłowska

Mgr Piotr Koza

Mgr Elżbieta Wróblewska