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

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

Impact of nutrients and water level changes on submerged macrophytes along a temperature gradient: A pan-European mesocosm experiment

Submerged macrophytes are of key importance for the structure and functioning of shallow lakes and can be decisive for maintaining them in a clear water state. The ongoing climate change affects the macrophytes through changes in temperature and precipitation, causing variations in nutrient load, water level and light availability. To investigate how these factors jointly determine macrophyte dominance and growth, we conducted a highly standardized pan-European experiment involving the installation of mesocosms in lakes. The experimental design consisted of mesotrophic and eutrophic nutrient conditions at 1 m (shallow) and 2 m (deep) depth along a latitudinal temperature gradient with average water temperatures ranging from 14.9 to 23.9 degrees C (Sweden to Greece) and a natural drop in water levels in the warmest countries (Greece and Turkey). We determined percent plant volume inhabited (PVI) of submerged macrophytes on a monthly basis for 5 months and dry weight at the end of the experiment. Over the temperature gradient, PVI was highest in the shallow mesotrophic mesocosms followed by intermediate levels in the shallow eutrophic and deep mesotrophic mesocosms, and lowest levels in the deep eutrophic mesocosms. We identified three pathways along which water temperature likely affected PVI, exhibiting (a) a direct positive effect if light was not limiting; (b) an indirect positive effect due to an evaporation-driven water level reduction, causing a nonlinear increase in mean available light; and (c) an indirect negative effect through algal growth and, thus, high light attenuation under eutrophic conditions. We conclude that high temperatures combined with a temperature-mediated water level decrease can counterbalance the negative effects of eutrophic conditions on macrophytes by enhancing the light availability. While a water level reduction can promote macrophyte dominance, an extreme reduction will likely decrease macrophyte biomass and, consequently, their capacity to function as a carbon store and food source

Rapid and highly variable warming of lake surface waters around the globe

In this first worldwide synthesis of in situ and satellite-derived lake data, we find that lake summer surface water temperatures rose rapidly (global mean = 0.34°C decade-1) between 1985 and 2009. Our analyses show that surface water warming rates are dependent on combinations of climate and local characteristics, rather than just lake location, leading to the counterintuitive result that regional consistency in lake warming is the exception, rather than the rule. The most rapidly warming lakes are widely geographically distributed, and their warming is associated with interactions among different climatic factors - from seasonally ice-covered lakes in areas where temperature and solar radiation are increasing while cloud cover is diminishing (0.72°C decade-1) to ice-free lakes experiencing increases in air temperature and solar radiation (0.53°C decade-1). The pervasive and rapid warming observed here signals the urgent need to incorporate climate impacts into vulnerability assessments and adaptation efforts for lakes

Relationships Between Lake Morphometry, Geographic Location and Water Quality Parameters of European Lakes

I addressed the question how lake and catchment morphometry influences water chemistry and water quality over a large scale of European lakes, and developed the regression equations between most closely related morphometric and water quality indices. I analysed the data of 1,337 lakes included in the European Environment Agency (EEA) database, carrying out separate analyses for three basic lake types: large lakes (area C100 km2, 138 lakes), shallow lakes (mean depth B3 m, 153 lakes) and large and shallow lakes (area C100 km2 and mean depth B8 m, 35 lakes). The study revealed that in Europe, the lakes towards North are larger but shallower and have smaller catchment areas than the southern lakes; lakes at higher altitudes are deeper and smaller and have smaller catchment areas than the lowland lakes. Larger lakes have generally larger catchment areas and bigger volumes, and they are deeper than smaller lakes, but the relative depth decreases with increasing surface area. The lakes at higher latitudes have lower alkalinity, pH and conductivity, and also lower concentrations of nitrogen and phosphorus while the concentration of organic matter is higher. In the lakes at higher altitudes, the concentration of organic matter and nutrient contents are lower and water is more transparent than in lowland lakes. In larger lakes with larger catchment area, the alkalinity, pH, conductivity and the concentrations of nutrients and organic matter are generally higher than in smaller lakes with smaller catchments. If the lake is deep and/or its residence time is long, the water is more transparent and the concentrations of chlorophyll a, organic matter and nutrients are lower than in shallower lakes with shorter residence times. The larger the catchment area is with respect to lake depth, area and volume, the lower is the water transparency and the higher are the concentrations of the nutrients, organic matter and chlorophyll as well as pH, alkalinity and conductivity. The links between lake water quality and morphometry become stronger towards large and shallow lakes. Along the decreasing gradients of latitude, altitude and relative depth, the present phosphorus concentration and its deviation from the reference concentration increases.JRC.H.5-Rural, water and ecosystem resource

Contemporary Trends of Temperature, Nutrient Loading and Water Quality in Large Lakes Peipsi and Võrtsjärv, Estonia

In 1961-2004, surface water temperature in the large and shallow Lakes Peipsi and Võrtsjärv in Estonia increased significantly in April and August, respectively, 0.37-0.75 and 0.32-0.42 degrees per decade reflecting the changes in air temperature. Also the average annual amount of precipitation in the catchment increased significantly. Reflecting practices in agriculture and wastewater treatment, nutrient loadings to the lakes increased rapidly in the 1980s and decreased again in the early 1990s. As total nitrogen (TN) loading decreased faster than total phosphorus (TP) loading, the TN/TP ratio in the loadings decreased. Both the increased temperature and low TN/TP ratio favoured the development of cyanobacteria blooms in Lake Peipsi. In Võrtsjärv, where the TN/TP mass ratio is about two times higher than in Peipsi, blooms did not occur. Recently, the TN/TP ratio has shown a tendency of increase in both lakes suggesting a certain reduction of blooms to be expected also in Lake Peipsi. Nutrient dynamics in the lakes followed the changes in loadings, showing the ability of shallow lake ecosystems to react sensitively to changes in catchment management as well as in climate.JRC.H.1-Water Resource