After Milly et al., 2005. Nature, 438(7066), 347–350


Download 490 b.
Sana06.06.2017
Hajmi490 b.



  • CIRCE wants to understand and to explain how climate will change in the Mediterranean area. The project will investigate how global and Mediterranean climates interact, how properties of the atmosphere, the radiactive fluxes vary, the interaction between cloudiness and aerosol, the modifications in the water cycle and implications on social and economic sectors.

  • IPCC 4AR

  • Many semi-arid and arid areas (e.g., the Mediterranean basin, western USA, southern Africa and north-eastern Brazil) are particularly exposed to the impacts of climate change and are projected (with high confidence) to suffer a decrease of water resources due to climate change.

  • There is an urgent need to understand and quantify the impact of projected climate change on hydrological processes including vegetation and crops (feedbacks).

  • Linkages between models for climate change and hydrological processes is crude, with models’ scales not relevant for decision making.



after Milly et al., 2005. Nature, 438(7066), 347–350 [in IPCC 4AR]

  • after Milly et al., 2005. Nature, 438(7066), 347–350 [in IPCC 4AR]





Objective:

  • Objective:

  • “Quantify the past variations and future projections in the water cycle in the Mediterranean Environment under global climate changes system.”





PART 1 : AIR, SEA AND PRECIPITATION: Past, Current and Future on Ocean, on Atmosphere, on Extremes and on Uncertainty; Mechanisms of climate variability in the Mediterranean Region

  • PART 1 : AIR, SEA AND PRECIPITATION: Past, Current and Future on Ocean, on Atmosphere, on Extremes and on Uncertainty; Mechanisms of climate variability in the Mediterranean Region

  • PART 2 : WATER: The hydrologic cycle: different components and interactions; Impacts of climate change on surface water, on ground water and coastal aquifer and on water quality.

  • PART 3 : AGRICULTURE, FORESTS AND ECOSYSTEM SERVICES: Climate change impacts on typical Mediterranean crops, forests and forest products, livestock population and productivity and evaluation of adaptation strategies to cope with. Vulnerability assessment of ecosystem services in the Mediterranean region,

  • PART 4 : PEOPLE: Water for people, Health, The general equilibrium approach, Policy innovation, Future visions of society in the Mediterranean

  • PART 5 : CASE STUDIES

    • Coastal Case Studies: Gulf of Valencia (Spain), Gulf of Oran (Algeria), Gulf of Gabes (Tunisia), Western Nile Delta (Egypt)
    • Rural Case Studies: Tuscany Region (Italy), Puglia Region (Italy), Judean Foothills (Israel), Tel Hadya (Syria).
    • Urban Case Studies: Alexandria (Egypt), Athens (Greece), Beirut (Lebanon),










Basin-scale testing of daily precipitation vs. 12 continuous precipitation records for 1961-1990

  • Basin-scale testing of daily precipitation vs. 12 continuous precipitation records for 1961-1990

  • Spatial averaging of point values over RCM grid-cells



Development of a downscaling approach based on a Poissonian scheme of the rainfall process

  • Development of a downscaling approach based on a Poissonian scheme of the rainfall process











This is a crucial field for the improvement of CC impact assessment in Mediterranean water cycle.

  • This is a crucial field for the improvement of CC impact assessment in Mediterranean water cycle.



The knowledge of current recharge and levels in both developed and developing countries is poor

  • The knowledge of current recharge and levels in both developed and developing countries is poor

  • Increased precipitation variability may decrease groundwater recharge in humid areas because more frequent heavy precipitation events may result in the infiltration capacity of the soil being exceeded more often.

  • In semi-arid and arid areas, however, increased precipitation variability may increase groundwater recharge, because only high-intensity rainfalls are able to infiltrate fast enough if there are a lot of macro pores… before evaporating.

  • Efforts to offset declining surface water availability due to increasing precipitation variability will be hampered by the fact that groundwater recharge is projected to decrease considerably in some water-stressed regions, exacerbated by the increased water demand

  • Groundwater would also be under pressure due to climate change, especially due to sea-level rise, shrinking land ice and permafrost areas, declining groundwater recharge.

  • Groundwater recharge is likely to be reduced in central and eastern Europe (Eitzinger et al., 2003), with a larger reduction in valleys (Krüger et al., 2002) and lowlands, e.g., in the Hungarian steppes: (Somlyódy, 2002).



Climate change will pose two major water management challenges in Europe: increasing water stress mainly in southeastern Europe, and increasing risk of floods throughout most of the continent.

  • Climate change will pose two major water management challenges in Europe: increasing water stress mainly in southeastern Europe, and increasing risk of floods throughout most of the continent.

  • Adaptation procedures and risk management practices for the water sector are being developed in some countries and regions (e.g., the Netherlands, the UK and Germany) that recognise the uncertainty of projected hydrological changes.



Reduce the uncertainty using a range of climate projections including a variety of climate models

  • Reduce the uncertainty using a range of climate projections including a variety of climate models

  • Evaluate groundwater recharge

  • Target monitoring, as quantitative as qualitative

  • Create an integrated quantitative risk and vulnerability assessment tool

  • Adaptation options which are robust against a range of future changes



Chloride ion is relatively stable and, usually, it is not affected by chemical reactions during the infiltration process.

  • Chloride ion is relatively stable and, usually, it is not affected by chemical reactions during the infiltration process.

  • The method is based on the following assumption:

  • precipitation and dry-atmospheric deposition are the only sources of chloride in groundwater and in surface-water runoff.

  • Human sources (septic systems, animal sources) and natural sources (evaporite rocks, connate seawater) contribute minimal amounts of chloride to the water.

  • As water percolates downward, the concentration of chloride in soil water increases with depth, but little or no chloride is lost by these processes.

  • At greater depths, where no evapotranspiration occurs, the chloride concentration should be uniform if climate, soil, and other conditions near the surface have been steady for a sufficiently long time.



Climate change could affect ground-water sustainability in several ways, including

  • Climate change could affect ground-water sustainability in several ways, including

    • 1) changes in ground-water recharge resulting from changes in average precipitation and temperature or in the seasonal distribution of precipitation,
    • 2) more severe and longer lasting droughts,
    • 3) changes in evapotranspiration resulting from changes in vegetation, and
    • 4) possible increased demands for ground water as a backup source of water supply.
  • The future climate may therefore have impacts on the hydrological regimes of groundwater storage-discharge dynamics which are difficult to predict.

  • Much more difficult will be the development of adaptation strategies to face such impacts in a world that is used to relay on groundwater a steady-state water resource.

  • As increasing attention is placed on the interactions of ground water with land and surface-water resources:

  • a) decreased baseflow components;

  • b) increased unsaturated zone capacity.



Large scale:

  • Large scale:

    • improving climate scenarios to be adopted in impact studies (dynamical/statistical downscaling),
    • availability of global hydrological database for groundwater storage
    • monitoring of water fluxes and storage states
    • improving groundwater representation in atmospheric simulation models (GCM/RCM)
    • improving global scale hydrological modelling with realistic parameterization of storage-discharge processes
  • Basin scale:

    • groundwater-surface water interaction in water balance models
    • groundwater-residence-time characterization
    • monitoring groundwater use with indirect measurements
  • Site scale:



The difficulties in monitoring the state of the groundwater results in an increasing perception of these resources as of unlimited availability.

  • The difficulties in monitoring the state of the groundwater results in an increasing perception of these resources as of unlimited availability.

  • Two negative impacts on the effectiveness of groundwater protection strategies:

  • 1.The decision makers to act on the resources without taking into account the needs and concerns of other actors.

  • 2. The strategies to protect the resources not acceptable by the end users (mainly farmers), particularly if the strategies aim to reduce the groundwater withdrawal.

  • A reduction of the effectiveness of groundwater management strategies with negative impacts on the state of the resources.

  • These impacts have to be added to those due to the climate changes..



Innovative research efforts are required to investigate the relationships existing between the three main elements of this topic:

  • Innovative research efforts are required to investigate the relationships existing between the three main elements of this topic:

    • the effect of climate change on the resource
    • the state of the groundwater resources
    • the degree of conflicts between the different actors,
    • the effectiveness of groundwater management strategies.





Do'stlaringiz bilan baham:


Ma'lumotlar bazasi mualliflik huquqi bilan himoyalangan ©fayllar.org 2017
ma'muriyatiga murojaat qiling