Review of Published Climate Change Adaptation and Mitigation Measures Related with Water

Stronger manifestation of climate change impact on global water cycle, water resources, and aquatic ecosystems has given a strong impetus to the development of adaptation measures in water management. The present report gives an insight to potential and planned water related measures tackling climate change causes and consequences, which have been included in the Member States River Basin Management Plans, published in various reports and scientific literature mostly within the last decade. The database of about 450 measures analysed in this report and given in a separate Annex as an Excel spreadsheet, constitutes the most important part of this deliverable. In the context of this report, measures are defined as practical steps or actions taken to (i) reduce the sources or enhance the sinks of greenhouse gases, (ii) to decrease the vulnerability of water resources and aquatic ecosystems to climate change, or (iii) enhance the knowledge base on climate-water relationships and increase the societal capacity to take right decisions on this matter. By strategic approach, the measures belong either to planned adaptation, which specifically focuses on climate change and variability, and autonomous adaptation, which goals are not specifically climate related, but have an added value in improving resilience to climate change. Separate chapters are dedicated to each of the five specific adaptation strategies addressed in the REFRESH Project. The present report is of relevance to the 7th EU Framework Programme, Theme 6 (Environment including Climate Change) project REFRESH (Adaptive strategies to Mitigate the Impacts of Climate Change on European Freshwater Ecosystems, Contract No.: 244121), to JRC Thematic Area 3 (Sustainable management of natural resources) foci on CC, to the European Clearing House mechanism on CC, and to the EC Blueprint on Water.JRC.DDG.H.5-Rural, water and ecosystem resource

Climate Change Adaptation and Mitigation Strategies already in practice based on the 1st River Basin Management Plans of the EU Member States

The decision whether or not to include climate change (CC) issues into the 1st River Basin Management Plans (RBMP) was depending on the availability of information and on the urgency of the CC related problems involved for each country. Most countries included a chapter to the 1st RBMP do describe the observed CC and its impacts to water resources management and carried out the ¿climate checking¿ of their programs of measures but the results were reported with a very different level of detail. The distinction of specific CC measures from the complex of measures dealing with floods, droughts and water quality protection, was rather arbitrary. In the Annex of present report the measures are categorized according to the original reports and, hence, some measures which are qualified as CC measures by one country may be not mentioned by other countries which did not consider the linkage to CC strong enough. Some of the measures in the Annex were not directly listed as measures in the management plans, but were picked out from the text discussing the tackling of climate impact. In present analysis, special attention was paid to adaptation measures addressing climate impact on ecosystems. This topic was rather scarcely presented in nine of the 18 RBMPs analysed. As the measures are translated from different languages, the wording does not pretend the full authenticity of the original text and for more detail it is suggested to consult the original plans in national languages. The present report is of relevance to the 7th EU Framework Programme, Theme 6 (Environment including Climate Change) project REFRESH (Adaptive strategies to Mitigate the Impacts of Climate Change on European Freshwater Ecosystems, Contract No.: 244121), to JRC Thematic Area 3 (Sustainable management of natural resources) foci on CC, to the European Clearing House mechanism on CC, and to the EC Blueprint on Water.JRC.DDG.H.5-Rural, water and ecosystem resource

Impacts of Climate Change on Physical Characteristics of Lakes in Europe

One of the tasks of the EEWAI action is the assessment of the impacts of climate change on ecological water quality in order to support the implementation of the Water Framework Directive. This task requires development of comprehensive knowledge base, models, and databases to provide tools for the evaluation of the adaptation needs of the EU water resources management with respect of the anticipated changes in water quality due to climate change. In 2008, EEWAI initiated a service contract between Joint Research Centre and Helsinki University of Technology in order to develop further a Decision Support System elaborated within the EU project CLIME into a new tool called CLIME Maps. The aim was to extend the central lake database, to update the computational basis of lake physical parameters by applying the newest achievements in this field of science, and enable creating map views of the projected changes of physical parameters of basic lake types. Based on the model results, this report gives an overview of the impacts that climate change may have on physical properties of lakes and demonstrates further implications that these changes have on lake ecosystems. The technical report on CLIME Maps and the users¿ manual are included in annexes of the report.JRC.H.5-Rural, water and ecosystem resource

Sediment phosphorus mobility in Vortsjarv, a large shallow lake : Insights from phosphorus sorption experiments and long-term monitoring

Sediment phosphorus (P) recycling is one of the key issues in lake water quality management. We studied sediment P mobility in Vortsjarv, a large shallow lake in Estonia using both sorption experiments and long-term (1985-2020) monitoring data of the lake. Over the years studied, the lake has undergone a dedine in external phosphorus loading (EL), while no improvement in phytoplankton indicators was observed. The results of the sorption experiments revealed that it may be successfully used as a tool to determine P forms involved in P retention, as up to 100% of the P from the water column was detected in sediments. Incubation of wet sediment is preferred to dry because of the sensitivity of organic P to desiccation. In the sediments of Vortsjarv, the labile P (Lab-P) and iron bound (Fe-P) fractions are the major forms of the mobile pool that supply internal P load as sediment released P. The internal P load calculated from summer total P (TP) increases (ILin situ) in the water column was on average 42%, but could reach 240% of EL at extreme environmental conditions. ILin situ was correlated with the active area, which resembles the area involved in redox-related P release in polymictic lakes, and with the mean bottom shear stress in summer. ILin situ showed a similar decreasing pattern as the external P load over the years 1985-2020, and was likely driven by the decrease of the pool of releasable P. Similarly, the decreases in sediment loading by P retention in our P sorption experiment were associated with decreases in the concentration of the potentially mobile P forms (mainly lab-P and Fe-P). These results show that changes in external P loading can successfully control internal P loading and are useful in water quality management of large lakes.Peer reviewe

* Corresponding author at: . E-mail address: (O. Tammeorg).

Lake Peipsi, one of the world's largest lakes, is shared between Estonia and Russia. The water quality in different parts of the lake has so far been assessed independently. Here we explore opportunities for com-bining data of Estonian and Russian monitoring. For that, we 1) analysed the compatibility of data for some water quality variables; 2) estimated the potential effects of the differences in sampling frequency; 3) provided a few regression models to calculate the missing data for months not sampled by the Russian side. Data of the concurrent Estonian and Russian sampling indicated a good compatibility. Estonian data analysis suggested that water quality assessment results are sensitive to sampling frequency. For exam-ple, total phosphorus (TP) in the largest basin showed a long-term decreasing trend in three month data that disappeared when data for other months were added. Disregarding some months may lead to under -or overestimation of certain factors with no consistency in the response of different basins. Hence, data of the whole ice-free period are recommended for an adequate water quality assessment. Furthermore, we demonstrated that monthly values of the water quality variables of the same year are autocorrelated. Based on this, we filled the gaps in the long-term data and compiled a dataset for the whole lake that enables its most comprehensive use in water quality assessment and management. Long-term data revealed no water quality improvement of Lake Peipsi. Further reduction of the external nutrient load is needed. Eutrophication is sustained by high internal phosphorus load.(c) 2022 The Authors. Published by Elsevier B.V. on behalf of International Association for Great Lakes Research. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/ 4.0/).Peer reviewe

Northern Hemisphere atmospheric stilling accelerates lake thermal responses to a warming world

Climate change, in particular the increase in air temperature, has been shown to influence lake thermal dynamics, with climatic warming resulting in higher surface temperatures, stronger stratification, and altered mixing regimes. Less-studied is the influence on lake thermal dynamics of atmospheric stilling, the decrease in near-surface wind speed observed in recent decades. Here we use a lake model to assess the influence of atmospheric stilling, on lake thermal dynamics across the Northern Hemisphere. From 1980-2016, lake thermal responses to warming have accelerated as a result of atmospheric stilling. Lake surface temperatures and thermal stability have changed at respective rates of 0.33 and 0.38°C decade-1, with atmospheric stilling contributing 15 and 27% of the calculated changes, respectively. Atmospheric stilling also resulted in a lengthening of stratification, contributing 23% of the calculated changes. Our results demonstrate that atmospheric stilling has influenced lake thermal responses to warming

Factors behind the variability of phosphorus accumulation in Finnish lakes

Phosphorus retention (TPacc) is one of the major water quality regulators in lakes. The current study aimed at ascertaining the specific lake characteristics regulating TPacc. Moreover, we were interested whether NAO (North Atlantic Oscillation), a proxy of climatic forcing, can explain variability in TPacc, additionally to that ascribed to lake characteristics. Sediment cores were obtained from 21 Finnish lakes, subject to radiometric dating and measurements of TP concentrations. Principal components (PCs) were generated using lake characteristics that are usually included into the modelling of TPacc (e.g. lake area, lake depth, catchment area, P inflow) but also the parameters that the classical models usually missed (e.g. anoxic factor). We used significant principal components (PCs), specific combinations of lake characteristics and monthly NAO values as predictors of TPacc. Lake characteristics explained the bulk of TPacc variability. The most influential factors (positive drivers) behind TPacc included PC1 (representing mainly deep lakes), PC2 (small lakes with high levels of anoxia and water column stability), PC3 (productive lakes with large catchment area and short water residence time), PC4 (lakes with high water column stability, low anoxic factor and relatively high sediment focusing) and PC5 (lakes with high levels of P inflow, anoxia and long water residence time). Additionally, we found a potential negative effect of NAO in October on the annual TPacc. This NAO was significantly positively related to temperatures in surface and near-bottom water layer (also their difference) in autumn, suggesting the possible implications for the internal P dynamics. Increased mineralization of organic matter is the most likely explanation for the reduced TPacc associated with NAO-driven water temperature increase. The analysis presented here contributes to the knowledge of the factors controlling P retention. Moreover, this spatially and temporally comprehensive sediment data can potentially be a valuable source for modelling climate change implications.Peer reviewe

Fisheries impacts on lake ecosystem structure in the context of a changing climate and trophic state

Through cascading effects within lake food webs, commercial and recreational fisheries may indirectly affect the abundances of organisms at lower trophic levels, such as phytoplankton, even if they are not directly consumed. So far, interactive effects of fisheries, changing trophic state and climate upon lake ecosystems have been largely overlooked. Here we analyse case studies from five European lake basins of differing trophic states (Lake Võrtsjärv, two basins of Windermere, Lake Geneva and Lake Maggiore) with long-term limnological and fisheries data. Decreasing phosphorus concentrations (re-oligotrophication) and increasing water temperatures have been reported in all five lake basins, while phytoplankton concentration has decreased only slightly or even increased in some cases. To examine possible ecosystem-scale effects of fisheries, we analysed correlations between fish and fisheries data, and other food web components and environmental factors. Re-oligotrophication over different ranges of the trophic scale induced different fish responsesIn the deeper lakes Geneva and Maggiore, we found a stronger link between phytoplankton and planktivorous fish and thus a more important cascading top-down effect than in other lakes. This connection makes careful ecosystem-based fisheries management extremely important for maintaining high water quality in such systems. We also demonstrated that increasing water temperature might favour piscivores at low phosphorus loading, but suppresses them at high phosphorus loading and might thus either enhance or diminish the cascading top-down control over phytoplankton with strong implications for water quality

Storm impacts on phytoplankton community dynamics in lakes

In many regions across the globe, extreme weather events such as storms have increased in frequency, intensity, and duration due to climate change. Ecological theory predicts that such extreme events should have large impacts on ecosystem structure and function. High winds and precipitation associated with storms can affect lakes via short-term runoff events from watersheds and physical mixing of the water column. In addition, lakes connected to rivers and streams will also experience flushing due to high flow rates. Although we have a well-developed understanding of how wind and precipitation events can alter lake physical processes and some aspects of biogeochemical cycling, our mechanistic understanding of the emergent responses of phytoplankton communities is poor. Here we provide a comprehensive synthesis that identifies how storms interact with lake and watershed attributes and their antecedent conditions to generate changes in lake physical and chemical environments. Such changes can restructure phytoplankton communities and their dynamics, as well as result in altered ecological function (e.g., carbon, nutrient and energy cycling) in the short- and long-term. We summarize the current understanding of storm-induced phytoplankton dynamics, identify knowledge gaps with a systematic review of the literature, and suggest future research directions across a gradient of lake types and environmental conditions.Peer reviewe