Social vulnerability to heatwaves – from assessment to implementation of adaptation measures in Košice and Trnava, Slovakia

Both Trnava and Kosice face rising heat. In Kosice, the ten hottest years in the last 150 years have all occurred since 1990; annual mean temperature rose 1.6C between 1881 and 2100; tropical days (mean temp above 30C) rose from 12 to 20 (37 in 2012) over the last 20 years, with maximum temperatures frequently exceeding 34C. In Trnava, summer days (mean temp above 25C) are projected to rise from 58 (1961-1990) to 100 (2051-2100), and tropical days from 12 to 36 over the same periods. Both cities face longer, more severe droughts; Trnava's precipitation is slightly falling (more in winter) while Kosice sees steady total precipitation but more torrential rain interspersed with dry periods.

Trnava (population about 68,000) is highly vulnerable to the urban heat island effect due to its historic character and high share of paved surfaces. Kosice (population about 240,000) has large numbers of residents in prefabricated blocks of flats prone to overheating. The Carpathian Development Institute, with local authorities, assessed heat vulnerability across Trnava and the densely populated, materially deprived Zapad district of Kosice (40,000 inhabitants), providing the basis for adaptation actions.

A grid-based (200m x 200m) vulnerability assessment in Zapad combined indicators (age structure, top-floor occupancy, insulation levels, paved/green area extent, temperature measurements, wind/air circulation, medical assistance availability) with a citizen survey on heatwave awareness and preferred measures, producing a vulnerability map. This informed a strategy including shading, cooling of public and indoor spaces (green stands targeting 60% tree-canopy coverage, insulation, green/reflecting roofs, some air conditioning), an early-warning system developed with the State Health Authority, education campaigns, and a 'climate-correct decision-making' programme embedding climate concerns into permitting. Trnava followed a similar assessment and transformed a neglected vulnerable site (near a block of flats, kindergarten and care home) by removing tarmac, planting trees for a future 60% crown coverage, building a fountain, adding benches, and introducing sustainable drainage. Trnava also set up an annual municipal adaptation grant budget (minimum 10,000 EUR/year), mainly supporting school awareness-raising activities to date.

Kosice's Zapad strategy was funded via the Hungary-Slovakia Cross-border Cooperation Programme 2007-2013 project 'Climcross Development'. Trnava's assessment and strategy were funded by the Swiss Financial Mechanism, which also provided 20,000 EUR for tree seedlings maintained by the city. Trnava's participatory adaptation grant scheme (minimum 10,000 EUR/year) is financed from the city budget. Effectiveness evaluation is planned five years after the Trnava site's 2019 completion.

The initiative proceeded without national adaptation regulation (Slovakia lacked a national adaptation action plan at the time); only Bratislava and Kezmarok besides these two had developed adaptation plans. Success factors were strong mayoral/city-leadership commitment in both cities, collaborative multi-stakeholder design led by the Carpathian Development Institute, and availability of external funding. Limiting factors include local officials' limited time/capacity given day-to-day duties and the novelty/complexity of the climate-adaptation topic.