• Energy Research

Water security demands guaranteeing economic, social and environmental sustainability and simultaneously addressing the diversity of risks and threats related to water. Various frameworks have been suggested to support water security assessment. They are typically based on indexes enabling national comparisons; these may, however, oversimplify complex and often contested water issues. We developed a structured and systemic way to assess water security and its future trends via a participatory process. The framework establishes a criteria hierarchy for water security, consisting of four main themes: the state of the water environment; human health and well-being; the sustainability of livelihoods; and the stability, functions and responsibility of society. The framework further enables the analysis of relationships between the water security criteria as well as between water, energy and food security. The framework was applied to a national water security assessment of Finland in 2018 and 2030. Our experience indicates that using the framework collaboratively with stakeholders provides a meaningful way to improve understanding and to facilitate discussion about the state of water security and the actions needed for its improvement.

Summary Understanding interlinkages among UN's Sustainable Development Goals (SDGs) is pivotal for the success of Agenda 2030. Here, we use water, a key sustainability resource, to advance SDG science by (1) assessing the synergies and trade-offs of improved water security on achieving the SDGs, (2) examining all the SDGs simultaneously, and (3) using a statistical analysis approach to synthesize the main interconnections. Our results show that water security positively contributed to all SDGs, especially SDG3 (good health) and SDG2 (zero hunger). Negative linkages (9% of all identified linkages) were potentially underrepresented and hampered critical assessment of water's links to the SDGs. The method may be used for other natural resources and their potential in supporting SDG implementation. Finally, more attention must be paid to the potential mutual benefits, and particularly the trade-offs, associated with SDG linkages.

Droughts pose a critical global risk that affect vast land areas and threaten almost all nations. Yet the impacts of droughts are most concretely felt at the local scale. Here, we assess drought indices in a Finnish basin with limited observations under current and future climate conditions in order to support local drought management. Long time series are needed for deriving drought indices, yet the available data is often a constraint. To increase the sample size available for analysis, we generated a thousand years of weather data with a stochastic weather generator based on observations and Regional Climate Model (RCM) data. The generated meteorological variables were fed into a hydrological model to simulate a large sample of hydrological variables. These large samples of simulated meteorological and hydrological variables were then used to analyse drought events and their characteristics in a past (1990–2019) and a future (2040–2069) time period. The results support the ongoing drought management work being done in South-Western Finland and specifically the Sirppujoki basin. Our results indicate that drought events will most likely become more frequent, especially during the growing season. Such changes would affect particularly the agricultural sector of Finland.

Data set of the linkages that water security has on other SDGs. The data are based on literature review and final data consists of 120 publications. The linkages are graded from -3 (cancelling) to +3 (indivisible) according Nilsson et al. classification. Prior to data collection, all the reviewers participated in training on SDGs and water security, and on review training before the work. Only papers with a link from water security to SDGs (not vice versa) were included. The resulting subset of 170 papers was then read and evaluated by all the authors independently, with a 10% random overlap on the papers (i.e. 17 of the papers were reviewed at least twice, by different people). During this process, another 50 papers were found to be irrelevant (e.g. due to full paper inaccessibility or questionnaire analysis with no inclusion of SDGs) and were therefore eliminated. The results are thus based on the 120 reviewed papers that we found to be suitable for the analysis. See the journal paper methods for more information, and Supplementary material for author bias analysis. The list of paper ID's can be found rom the journal paper in One Earth. Column "Review" indicates whether the analyzed publication was a review or an original research paper. 1_waterresources_sec = an identified linkage to the water resources dimension of the water security concept 2_human_sec = an identified linkage to the human security dimension of the water security concept 3_national_sec = = an identified linkage to the national security dimension of the water security concept 4_climate_sec = an identified linkage to the climate security dimension of the water security concept 5_energy_sec = an identified linkage to the energy security dimension of the water security concept 6_food_sec = an identified linkage to the food security dimension of the water security concept sdg_counts = the total number of SDGs with reported linkage of water security year = publication year 

Severe droughts can affect water security even in countries with ample water resources. In addition, droughts are estimated to become more frequent in several regions due to changing climate. Drought affects many socio-economic sectors (e.g., agriculture, water supply, and industry), as it did in 2018 in Finland. Understanding the basin-wide picture is crucial in drought management planning. To identify vulnerable and water stressed areas in Finland, a water use-to-availability analysis was executed with a reference drought. Water stress was analyzed with the Water Depletion Index WDI. The analysis was executed using national water permits and databases. To represent a severe but realistic drought event, we modelled discharges and runoffs from the worst drought of the last century in Finland (1939–1942). The potential for performing similar analyses in data scarce contexts was also tested using estimates from global models as a screening tool. The results show that the South and Southwest of Finland would have problems with water availability during a severe drought. The most vulnerable areas would benefit from drought mitigation measures and management plans. These measures could be incorporated into the EU River Basin Management Plans.

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.