Soil moisture - atmosphere interaction and extreme hydrological conditions

Dolman, A.J. [Promotor

Recycling of moisture in Europe: contribution of evaporation to variability in very wet and dry years

Evaporation is a key parameter in the regional atmospheric water cycle. Precipitation recycling is defined as the contribution of water that evaporates from a region to precipitation within the same region. We apply a dynamic precipitation recycling model, which includes a dynamic moisture storage term, to calculate the warm season variability of the precipitation recycling over central Europe at a daily time scale for 2003 (dry) and 2006 (wet). <br><br> For the central part of Europe advection is the most important contributor to precipitation. In dry spells in both years 2003 and 2006, when moisture of advective origin diminishes, local evaporation becomes an important contributor to precipitation (negative feedback). In two dry periods (June 2003 and July 2006) where there is enough moisture storage in the soil to continue evaporation, precipitation recycling is enhanced. In case studies we follow the path of an air column for days with high precipitation recycling to discuss the role of moisture recycling in land-atmosphere interactions. For 2 days with enough moisture availability (28 May 2003 and 5 July 2006) moisture particles stay long in the study area due to weak winds. By following the paths we show that the air is transported over land for a very long distance before it precipitates. It thus takes a considerable amount of time to traverse the region and capture moisture of evaporative origin. However, we hypothesize that the precipitation falling on those days still originates (partly) from oceanic sources, but that the triggering of precipitation may itself be a result of enhanced instability induced by soils, which still have sufficient moisture storage. In dry periods with enough moisture available precipitation recycling acts as a mechanism to keep the precipitation at a stable level. <br><br> In August 2003 evaporation is affecting the precipitation recycling due to the lack of water availability caused by the dryness of the preceding spring and summer season. According to a Granger Causality test the evaporation in 2003 exerts the strongest causal impact on the precipitation recycling ratio. For the case study of 10 August 2003, the atmosphere is too dry to generate precipitation with exception of the mountainous regions due to orographical lifting

Future Projections of Water Scarcity in the Danube River Basin Due to Land Use, Water Demand and Climate Change

This paper presents a state-of-the-art integrated model assessment to estimate the impacts of the 2°C global mean temperature increase and the 2061-2090 warming period on water scarcity in the Danube River Basin under the RCP8.5 scenario. The Water Exploitation Index Plus (WEI+) is used to calculate changes in both spatial extent and people exposed to water scarcity due to land use, water demand, population and climate change. Despite model and data uncertainties, the combined effects of projected land use, water demand and climate change show a decrease in the number of people exposed to water scarcity during the 2°C warming period and an increase in the 2061-2090 period in the Danube River Basin. However, the projected population change results in a decrease of exposed people in both warming periods. Regions with population growth, in the northwestern part of the Danube River Basin experience low water scarcity or a decrease in water scarcity. The largest number of people vulnerable to water scarcity within the Danube River Basin are living in the Great Morava, Bulgarian Danube and Romanian Danube. There, the combined effects of land use, water demand and climate change exacerbate already existing water scarce areas during the 2°C warming period and towards the end of the century new water scarce areas are created. Although less critical during the 2°C warming period, adjacent regions such as the Tisza, Middle Danube and Siret-Prut are susceptible to experience similar exposure to water scarcity within the 2061-2090 period. Climate change is the most important driver for the increase in water scarcity in these regions, but the strengthening effect of water demand (energy sector) and dampening effect of land use change (urbanization) does play a role as well. Therefore, while preparing for times of increased pressures on the water supply it would be advisable for several economic sectors to explore and implement water efficiency measures

Water scenarios for the Danube River Basin: Elements for the assessment of the Danube agriculture-energy-water nexus

This report provides background material for the identification and elicitation of scenarios relevant for the futures of the agriculture-energy-ecosystems-water nexus in the Danube region. We present a summary of the regional climate scenarios available as input for water resources simulations, and the consequent long term average water balance figures estimated using a Budyko framework. Then we introduce the LUISA model for the simulation of land use-related variables in the region. Finally, we include a contribution by a water expert from the Danube region, presenting an initial reasoning on important elements to be addressed in scenario simulations. This report is intended as a reader for water professionals, stakeholders and decision makers in the Danube region, in order to stimulate the foresight of scenarios worth being simulated with JRC models, so to further our understanding of the water-energy-agriculture-ecosystems nexus and its management in the mid- and long-term.JRC.H.1-Water Resource

The water-energy nexus and the implications for the flexibility of the Greek power system

The operation of the power systems is constrained by the availability of water resources, which are necessary for cooling thermal power plants and determine the generation of hydro reservoirs and run-of-river power plants. The interactions between the water and power systems have impacts on the quantity and quality of the water resources, thus affecting human uses and the environment. The European power system has witnessed in the past several examples of the consequences of reduced availability of water, which range from monetary losses, to demand restrictions, or increased wear and tear of the power plants. The importance of these impacts, and the expectation that climate change will produce similar episodes in the future more often, raises several research questions relevant for policy making. Some of these questions may be addressed by WATERFLEX, an exploratory research project carried out by units C7 (Knowledge for the Energy Union) and D2 (Water and Marine Resources) of the European Commission's Joint Research Centre (JRC). The main goal of WATERFLEX is to assess the potential of hydropower as a source of flexibility to the European power system, as well as analysing the Water-Energy nexus against the background of the EU initiatives towards a low-carbon energy system. The method proposed in the WATERFLEX project for better representing and analysing the complex interdependencies between the power and water sectors consists of combining two of the modelling tools available at the JRC, the LISFLOOD hydrological model [1] and the Dispa-SET unit commitment and dispatch model [2], with a medium-term hydrothermal coordination model. In order to test and validate the proposed approach described above, this document describes a case study carried out to analyse the implications of different hydrologic scenarios for the flexibility of the Greek power system.JRC.C.7-Knowledge for the Energy Unio

Climate change and Europe’s water resources

In addition to the already existing pressure on our freshwater resources, climate change may further decrease water availability. In this study, projections of future water resources, due to climate change, land use change and changes in water consumption have been assessed using JRC’s LISFLOOD water resources model. The results presented are based on 11 climate models which project current and future climate under two Representative Concentration Pathways (RCPs): RCP4.5 and RCP 8.5 emission scenario. RCP4.5 may be viewed as a moderate-emissions-mitigation-policy scenario and RCP8.5 as a high-end emissions scenario. A 30-year window around the year that global warming reaches 1.5oC, 2oC and 3oC above preindustrial temperature has been analysed and compared to the 1981-2010 control climate window (baseline). The 1.5°C and 2°C warming scenarios are explicitly considered in the Paris Agreement, while a 3°C global warming is a scenario that could be expected by the end of the 21st century if adequate mitigation strategies are not taken. First, we performed future projections without socio-economic developments to show the effect of climate change only. Next, an integrated assessment is performed including future changes in land use, water demand and population. This allows us to disentangle the effects of climate and socio-economic changes. In general, the climate projections reveal a typically North-South pattern across Europe for water availability. Overall, Southern European countries are projected to face decreasing water availability, particularly Spain, Portugal, Greece, Cyprus, Malta, Italy and Turkey. Central and Northern European countries show an increasing annual water availability.JRC.D.2-Water and Marine Resource

Mild desalination demo pilot: New normalization approach to effectively evaluate electrodialysis reversal technology

AbstractKey performance indicators for characterization of nanofiltration performance are well developed, similar key performance indicators for electrodialysis reversal are however underdeveloped. Under the E4Water project Dow Benelux BV and Evides Industriewater BV operate a pilot facility to compare both technologies for their application to mildly desalinate a variety of brackish water streams. Normalized pressure drop, normalized current efficiency and normalized membrane resistance proved to be a useful tool to interpret process performance and to initiate a cleaning procedure if required. The availability of these normalized key performance indicators enables optimization and process monitoring and control of electrodialysis reversal independent of the continuously changing conditions of the feed water

The water-power nexus of the Iberian Peninsula power system: WATERFLEX project

Water availability influences power generation and its costs. Policies aimed at keeping the water stress index of thermal power plants within acceptable limits are needed. This report provides a model-based analysis of the water-power nexus in the Iberian Peninsula.JRC.C.7-Knowledge for the Energy Unio

Impact of a changing climate, land use, and water usage on water resources in the Danube river basin

Impact of a changing climate, land use, and water usage on water resources in the Danube river basinJRC.D.2-Water and Marine Resource