Projected soil drought development in Czechia (2021–2050; 2051–2080) using high-resolution ALADIN-Climate/CZ regional model.

The ALADIN-Climate/CZ regional climate model, operating at a high resolution of 2.3 km, was utilised to project future occurrences of soil drought in Czechia. GCM ARPEGE-Climate drives the regional climate model. To assess the effects of weather conditions on soil drought, we developed a simple model simulating the soil moisture based on API30 and near-surface air temperature, calibrated against observations. Using simulations of future climate, we predict soil drought. Drought was defined as a soil water content below 30% of the maximum water-holding capacity.

According to the medium emissions scenario, there is an expected average rise in the number of days with soil drought in the arable layer by 46% and 106% during 2021-2050 and 2051-2080, respectively, compared to the baseline period of 1991-2020. Additionally, there is a notable increase in the percentage of land affected by drought, with areas experiencing drought for over 50 days increasing by 15.5% and 53.2% by 2050 and 2080, respectively. Higher intensity of soil drought is evident across the country, particularly pronounced at higher elevations due to rising temperatures and reduced precipitation amounts. These observed changes emphasise the urgent need to implement adaptation measures in agriculture and alter agricultural land management practices.

This work was supported by the Technology Agency of the Czech Republic (Prediction, Evaluation and Research for Understanding National Sensitivity and Impacts of Drought and Climate Change for Czechia, SS02030040 and Centre for Landscape and Biodiversity, SS02030018).

Keywords: soil drought, soil water, precipitation, temperature, climate change, regional climate model, climate change scenario, adaptation measures in agriculture