Severe Drought in Finland: Modeling Effects on Water Resources and Assessing Climate Change Impacts

Abstract

Severe droughts cause substantial damage to different socio-economic sectors, and even Finland, which has abundant water resources, is not immune to their impacts. To assess the implications of a severe drought in Finland, we carried out a national scale drought impact analysis. Firstly, we simulated water levels and discharges during the severe drought of 1939–1942 (the reference drought) in present-day Finland with a hydrological model. Secondly, we estimated how climate change would alter droughts. Thirdly, we assessed the impact of drought on key water use sectors, with a focus on hydropower and water supply. The results indicate that the long-lasting reference drought caused the discharges to decrease at most by 80% compared to the average annual minimum discharges. The water levels generally fell to the lowest levels in the largest lakes in Central and South-Eastern Finland. Climate change scenarios project on average a small decrease in the lowest water levels during droughts. Severe drought would have a significant impact on water-related sectors, reducing water supply and hydropower production. In this way drought is a risk multiplier for the water–energy–food security nexus. We suggest that the resilience to droughts could be improved with region-specific drought management plans and by including droughts in existing regional preparedness exercises.

<i>Sphaeropsis sapinea</i> found as symptomless endophyte in Finland

“…The average annual precipitation sums were observed to vary from 450 mm in Northern Lapland to 750 mm in Southern and Eastern Finland for 1981-2010 (Pirinen et al 2012). Veijalainen et al (2019) analyzed that drought risk due to climate change can increase in Southern and Central Finland. Especially the drought risk during summer and early autumn can escalate due to an increase in temperature and longer summer periods (Veijalainen et al 2019).…”

“…When the local environment changes and an increase in drought/temperature-associated stress may be observed, Scots pines become more susceptible to pathogens (Stanosz et al 2001;Bußkamp 2018). Southern Finland is a high-risk drought area (Veijalainen et al 2019), where a dry growing season may result in a 30-50% probability of detecting physiological changes such as defoliation, decreased carbon and nutrient assimilation, and breakdown of the photosynthetic process through loss of hydraulic conductivity in forest trees (Muukkonen et al 2015).…”

Can There be Water Scarcity with Abundance of Water? Analyzing Water Stress during a Severe Drought in Finland

“…Since climate change has already increased the temperatures in Finland over 2 degrees [67], these kinds of cold winters have become rarer. According to the results of Veijalainen et al [66], however, climate change would not significantly change the 1939-1942 drought severity. Winters would become somewhat wetter and summers drier, but the general water availability would change only modestly.…”

“…The actual drought lasted for 3.5 years, starting in May 1939 and ending in November 1942, yet to understand seasonal variation, we extend the analysis to the full calendar years 1939-1942. The return period of this hydrological drought was estimated to be once in 100-150 years for most of Finland [65], and it is modelled and described in more detail by Veijalainen et al [66]. The observed temperature and precipitation were used to simulate the runoff and discharges of 1939-1942 using the WSFS model, but with the current regulation rules and dams in the catchments.…”

Enhancing Security, Sustainability and Resilience in Energy, Food and Water

“…Noora Veijalainen et al carry out a national scale drought impact analysis for Finland, assessing the effects of a severe drought on water resources in Finland [50]. The analysis includes three main phases: simulating water levels and discharges during a severe reference drought, estimating how climate change would alter droughts, and assessing their impact on key water use sectors such as hydropower production and water supply.…”