Malgorzata KIJOWSKA-STRUGALA, Polish Academy of Sciences, Institute of Geography and Spatial Organization, Poland
Witold BOCHENEK, Polish Academy of Sciences, Institute of Geography and Spatial Organization, Poland
Climate change and human activity are key factors affecting changes in the flow regime, water availability and quality of aquatic ecosystems (Goudie, 2020). According to the latest report by the IPCC (IPCC, 2021), the average global temperature will increase by 1.5°C in the next 20 years. Mountains are highly sensitive to the effects of climate change and human activity, especially land use and land cover changes (LULC). In the last few decades, the LULC in the analyzed Bystrzanka catchment (13 km2, located in the Polish Western Carpathians) showed a tendency to reduce the area of cultivated land and increase of grassland and forest areas (Kijowska-Strugala, 2019). This direction of LULC changes are typical of the Western Carpathians.
Based on the SWAT model, forecasting of changes of the runoff and nitrate nitrogen load (LdNO3-N) was performed in three periods: 2021-2030 (1st), 2031-2040 (2nd) and 2041-2050 (3rd) for the mountain catchment. The reference period was 2011-2020. In addition, in order to determine the impact of LULC changes on analyzed parameters, the scenario of a total lack of cultivated land and the replacement of this form of land use by grassland was adopted.
The analysis showed that the average annual sums of runoff in three simulated periods was higher by 12% than in the reference period. Due to climate change the LdNO3-N in the 1st and 2nd periods will decrease by 11% and 15%, respectively and in 3rd period will increase by 3% in compare to reference period. The lack of cultivated land will reduce the average annual LdNO3-N by 34% in the 1st and by 29% in the 2nd and 3rd periods compared to the forecast period with LULC from 2015.
The research indicates that planning and managing the effects of LULC changes is of key importance for sustainable development in terms of the quantity and quality of water.
Mots clés : land use change|climate change|runoff|nitrate nitrogen load|Polish Carpathians
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