Browsing by Author "Ahopelto, Lauri"

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  • Can There be Water Scarcity with Abundance of Water? Analyzing Water Stress during a Severe Drought in Finland
    (2019-03-02) Ahopelto, Lauri; Veijalainen, Noora; Guillaume, Joseph H. A.; Keskinen, Marko; Marttunen, Mika; Varis, Olli
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    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.
  • Drought hazard and annual precipitation predicted to increase in the Sirppujoki river basin, Finland
    (2023-08) Ahopelto, Lauri; Kallio, Marko; Veijalainen, Noora; Kouki, Roope; Keskinen, Marko
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    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.
  • Drought in Water Abundant Finland - Data and Tools for Drought Management
    (2024) Ahopelto, Lauri
     School of Engineering | Doctoral dissertation (article-based)
    Droughts pose a risk to all societies, even those with abundant water resources. Climate change will affect this risk, and societies should adapt accordingly. Though Finland has a low drought risk, recent droughts have had a clear impact, especially on agriculture and water supply, but also forestry, hydropower, and ecosystems. While Finland's water governance and water security are generally at a good level, drought has so far gained little attention and operative drought management plans and strategies are absent. This dissertation studies drought risks in Finland and provides recommendations on how to improve drought management. Drought risk can generally be understood as a combination of three factors: vulnerability, exposure, and hazard. Several drought indices, models, and weather data generation are used in the dissertation to better understand drought hazard and to quantify drought frequency, severity, and other characteristics of drought events in Finland. The dissertation also considers how drought hazard might change due to climate change. The results are discussed in relation to different sectors and within the broader water governance context in Finland. The results from the drought index analyses provide detailed information on drought characteristics in Finland. The findings show that choosing the best drought indices for different contexts is difficult, emphasizing the need to use several indices. For the Sirppujoki basin case study (a river basin in southwestern Finland), 2o different standardized drought indices were calculated for two drought events of 2002–2003 and 2018 as well as for the years 2040–2069. In addition, weather data generation coupled with hydrological modeling was tested for the basin. This dissertation reveals that drought risks will likely increase due to climate change, predominantly in the south and southwest Finland. Based on evapo-transpiration-dependent indices, drought events are predicted to increase especially during the growing season. This is particularly worrying for the agricultural sector, since only a few percent of fields have irrigation systems. However, the climate scenarios have a large variation, emphasizing the need for more research as well as flexible climate change adaptation. To address the growing drought risk in Finland, adaptation measures against drought impacts are suggested. A national drought strategy, together with bot-tom-up drought management plans, would mitigate the increasing drought risks. These should be accompanied with a systematic drought management process with an early warning system.
  • The effects of drought on Finnish cereal grain production
    (2019-10-21) Kouki, Roope
     Insinööritieteiden korkeakoulu | Master's thesis
    This study had three main aims: (1) to analyse the effects of agricultural drought in Finland and their spatial distribution; (2) to assess the economic potential of irrigation as a drought mitigation measure; and (3) to assess the usefulness and functionality of a cloud-based geospatial tool (Earth Engine). To achieve these aims, a large amount of geospatial data was aggregated and averaged to a regional and annual level with Earth Engine. Correlations between these regional annual average values and matching cereal grain production statistics were examined. To analyse yield fluctuations at a smaller spatial scale than that of the production statistics, a regression model was built based on all variables which showed statistically significant correlations with grain yields. Based on modelled 2018 yield losses in Southwest Finland, an estimate of the economic benefit of irrigation was produced. The results show a clear divide between the south and southwest and more eastern and northern parts of the country in terms of vulnerability to agricultural drought. The results also show a considerable degree of local variation in dry-year yield losses and the potential economic benefit of irrigation within Southwest Finland. Based on the results, even though irrigation of cereal grains seems to make economic sense only in small, fairly well-defined parts of the study area, it could have some promise as a protective measure against dry-year yield losses. Earth Engine was found to be a powerful, if imperfect, tool for geospatial analysis. It is especially suited to large-scale repetition of simple tasks on large amounts of geospatial data.
  • European Unions new water scarcity indicator and its application in Finland
    (2013) Ahopelto, Lauri
     School of Engineering | Master's thesis
    Water scarcity is defined as human-induced excessive water use in relation to the available water resources. The objective of this thesis was to apply the new EU water scarcity indicator (Water Exploitation Index +, WEI+) in Finland to find out whether there has been water scarcity in Finland during years 2000-2011. The second objective was to examine whether WEI+ indicator is better than the earlier water scarcity indicators. The indicator is a part of the European Commission's new blueprint to safeguard Europe's waters, which was released in November 2012. WEI+ analysis was carried out in Finland annually for 37 water basins, and of these, twelve were also tested on a monthly basis. In addition, a case study was carried out with the indicator for an artificial ground water project in Virttaankangas to assess its impacts on water scarcity. The indicator was also evaluated on six criteria. WEI+ analysis assesses the human-induced stress towards the water basin. The water that returns to the basin after use is reduced from the abstraction of water. The result is then divided by the amount of natural water resources. The resulting percentage value is compared to threshold values that indicate the severity of water scarcity. Abstraction and returned water are not measured accurately in Finland. Therefore, the values are largely based on the literature. The results show that Finland does not have annual water scarcity, but slight seasonal water scarcity occurs during summers in the river Aurajoki, river Uskelajoki, river Sirppujoki and river Paimionjoki. With further studies in mind, it is advisable to make an annual analysis of all the Finnish water basins and in addition the monthly analysis, if the annual analysis is more than one per cent or the total agricultural area of the basin is more than 20%. The artificial ground water project in Virttaankangas is a great project in terms of water scarcity, because it would eliminate the seasonal water scarcity in river Aurajoki and river Paimionjoki. One of the most important features of the Water scarcity indicator, besides raising awareness, is its ability to show areas that are more prone to drought. Decision makers are able to target these areas with more studies and possibly water saving techniques in the future.
  • A framework for assessing water security and the water-energy-food nexus-the case of Finland
    (2019-05-01) Marttunen, Mika; Mustajoki, Jyri; Sojamo, Suvi; Ahopelto, Lauri; Keskinen, Marko
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    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.
  • Globally widespread and increasing violations of environmental flow envelopes
    (2022-07-01) Virkki, Vili; Alanärä, Elina; Porkka, Miina; Ahopelto, Lauri; Gleeson, Tom; Mohan, Chinchu; Wang-Erlandsson, Lan; Flörke, Martina; Gerten, Dieter; Gosling, Simon N.; Hanasaki, Naota; Müller Schmied, Hannes; Wanders, Niko; Kummu, Matti
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Human actions and climate change have drastically altered river flows across the world, resulting in adverse effects on riverine ecosystems. Environmental flows (EFs) have emerged as a prominent tool for safeguarding the riverine ecosystems, but at the global scale, the assessment of EFs is associated with high uncertainty related to the hydrological data and EF methods employed. Here, we present a novel, in-depth global EF assessment using environmental flow envelopes (EFEs). Sub-basin-specific EFEs are determined for approximately 4400 sub-basins at a monthly time resolution, and their derivation considers the methodological uncertainties related to global-scale EF studies. In addition to a lower bound of discharge based on existing EF methods, we introduce an upper bound of discharge in the EFE. This upper bound enables areas to be identified where streamflow has substantially increased above natural levels. Further, instead of only showing whether EFs are violated over a time period, we quantify, for the first time, the frequency, severity, and trends of EFE violations during the recent historical period. Discharge was derived from global hydrological model outputs from the ISIMIP 2b ensemble. We use pre-industrial (1801-1860) quasi-natural discharge together with a suite of hydrological EF methods to estimate the EFEs. We then compare the EFEs with recent historical (1976-2005) discharge to assess the violations of the EFE. These violations most commonly manifest as insufficient streamflow during the low-flow season, with fewer violations during the intermediate-flow season, and only a few violations during the high-flow season. The EFE violations are widespread and occur in half of the sub-basins of the world during more than 5% of the months between 1976 and 2005, which is double compared with the pre-industrial period. The trends in EFE violations have mainly been increasing, which will likely continue in the future with the projected hydroclimatic changes and increases in anthropogenic water use. Indications of increased upper extreme streamflow through EFE upper bound violations are relatively scarce and dispersed. Although local fine-tuning is necessary for practical applications, and further research on the coupling between quantitative discharge and riverine ecosystem responses at the global scale is required, the EFEs provide a quick and globally robust way of determining environmental flow allocations at the sub-basin scale to inform global research and policies on water resources management.
  • Hulevesien luonnonmukainen hallinta
    (2009) Ahopelto, Lauri
     Insinööritieteiden ja arkkitehtuurin tiedekunta | Bachelor's thesis
  • Lessons from the 2018-2019 European droughts : a collective need for unifying drought risk management
    (2022-06-29) Blauhut, Veit; Stoelzle, Michael; Ahopelto, Lauri; Brunner, Manuela I.; Teutschbein, Claudia; Wendt, Doris E.; Akstinas, Vytautas; Bakke, Sigrid J.; Barker, Lucy J.; Bartošová, Lenka; Briede, Agrita; Cammalleri, Carmelo; Kalin, Ksenija Cindrić; De Stefano, Lucia; Fendeková, Miriam; Finger, David C.; Huysmans, Marijke; Ivanov, Mirjana; Jaagus, Jaak; Jakubínský, Jiri; Krakovska, Svitlana; Laaha, Gregor; Lakatos, Monika; Manevski, Kiril; Neumann Andersen, Mathias; Nikolova, Nina; Osuch, Marzena; Van Oel, Pieter; Radeva, Kalina; Romanowicz, Renata J.; Toth, Elena; Trnka, Mirek; Urošev, Marko; Urquijo Reguera, Julia; Sauquet, Eric; Stevkov, Aleksandra; Tallaksen, Lena M.; Trofimova, Iryna; Van Loon, Anne F.; Van Vliet, Michelle T.H.; Vidal, Jean Philippe; Wanders, Niko; Werner, Micha; Willems, Patrick; Zivković, Nenad
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Drought events and their impacts vary spatially and temporally due to diverse pedo-climatic and hydrologic conditions, as well as variations in exposure and vulnerability, such as demographics and response actions. While hazard severity and frequency of past drought events have been studied in detail, little is known about the effect of drought management strategies on the actual impacts and how the hazard is perceived by relevant stakeholders. In a continental study, we characterised and assessed the impacts and the perceptions of two recent drought events (2018 and 2019) in Europe and examined the relationship between management strategies and drought perception, hazard, and impact. The study was based on a pan-European survey involving national representatives from 28 countries and relevant stakeholders responding to a standard questionnaire. The survey focused on collecting information on stakeholders' perceptions of drought, impacts on water resources and beyond, water availability, and current drought management strategies on national and regional scales. The survey results were compared with the actual drought hazard information registered by the European Drought Observatory (EDO) for 2018 and 2019. The results highlighted high diversity in drought perception across different countries and in values of the implemented drought management strategies to alleviate impacts by increasing national and sub-national awareness and resilience. The study identifies an urgent need to further reduce drought impacts by constructing and implementing a European macro-level drought governance approach, such as a directive, which would strengthen national drought management and mitigate damage to human and natural assets.
  • Severe Drought in Finland: Modeling Effects on Water Resources and Assessing Climate Change Impacts
    (2019-04-01) Veijalainen, Noora; Ahopelto, Lauri; Marttunen, Mika; Jääskeläinen, Jaakko; Britschgi, Ritva; Orvomaa, Mirjam; Belinskij, Antti; Keskinen, Marko
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    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.
  • The sustainability of global river systems based on sub-basin specific environmental flow envelopes
    (2020-08-17) Alanärä, Elina
     Insinööritieteiden korkeakoulu | Master's thesis
    The functionality of riverine ecosystems and the related ecosystem services is threatened as a result of anthropogenic water withdrawals and flow regulation, which alter the natural flow regimes of rivers. In this thesis, the sustainability of global river systems was assessed based on the violation of the environmental flow envelopes. The sub-basin specific environmental flow envelopes were used to define the flow regime required to sustain the local ecosystem on a monthly scale. The environmental flow envelopes were based on the concepts of environmental flows and environmental flow requirements, which are used to quantify the amount of water needed to sustain the ecosystems. The flow envelopes were defined based on the pre-industrial discharges to consider the ecosystem water needs without significant human impact. The violation was then analysed by comparing if the post-industrial discharges were within the defined flow envelopes. The study was conducted as a data-analysis and consisted of three main parts: the pre-processing of the data, the environmental flow envelope estimation and analysing the violation of the environmental flow envelopes. Five different environmental flow methods and flow statistics were used to estimate the upper and lower boundaries of the local environmental flow envelopes. The violation was analysed by calculating the percentage of months violated of the total period of interest, but only months in which the violation was consequent for over three months were considered. The results indicate, that the ecosystem water needs were violated in many parts of the world, but there was considerable variation both spatially and temporally. The most significant violation was present in hot and arid regions of the world. Furthermore, the violation was most severe during the hottest and driest months. Water use and especially increase in irrigation were considered the most significant reasons for violation. However, also climate change, land-use change and reservoir operation were recognised to have an impact. Identifying the most critical areas regarding the ecosystem functionality is important as the freshwater use and flow alteration have been expected to increase further.
  • Water governance for water security: analysing institutional strengths and challenges in Finland
    (2024) Ahopelto, Lauri; Sojamo, Suvi; Belinskij, Antti; Soininen, Niko; Keskinen, Marko
     A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    The relationship between water security and water governance across different water-using sectors remains under-researched. We apply the Organisation for Economic Co-operation and Development’s (OECD) Water Governance Indicator Framework with revised principles and criteria to analyse three sectors critical to water security in Finland: bioeconomy, mining and water infrastructure. Our findings indicate that water security as a concept helps to both assess and clarify governance priorities, while well-functioning governance with engagement of key actors is a prerequisite for broader water security. Given the differing interests and emerging pressures related to water, ensuring water security requires well-resourced public sector agencies to coordinate interaction across sectors and actors.