Abstract
In this chapter, the author discusses the importance of mitigation and adaptation actions needed to be taken from an environmental and engineering standpoint in regards to dams, reservoirs they form, the river basins they serve, and how this can benefit these systems in the future. One of the main problems identified for the mid-21st century will be the availability of fresh water. Currently, appx. 20% of the world's freshwater is stored in manmade reservoirs. However, these reservoirs sediment over time. This “sediment phenomena'' adversely affects the water volume in reservoirs and their sustainable maintenance, potentially jeopardizing water supply and lives. To answer the “sediment phenomena,'' this chapter will explore a new approach to a no less devastating problem of land degradation, developed at the Technical University of Vienna. In the Balkan region, sediments are mostly composed of alluvial soil, decomposing organic matter, and sands, making them indeed a perfect soil amendment for degraded lands and barren topsoil terrains destroyed during torrential floods and landslides.
TopIntroduction
Climate Change is a very complex issue of our time, and as such many international, intergovernmental and academic institutions worldwide have been trying to propose the best actionable advice to be considered by authorities when dealing with disaster aftermath, preparing for them and or risk assessment for such events.
Climate Change will have various consequences on Europe and the Balkans as its integral part, such as droughts, forest fires, river floods, which will all be felt throughout our economies.
Droughts are expected to be more severe and persistent in most of Europe, except for northern parts of Europe, including Baltic states and most northeast. South of Europe, including the Balkans will face strong reductions in low flows and experience agricultural droughts that can be expected to increase up to 7-fold in the various simulations, reaching 700,000 km2/year, almost twice the area of Germany.
The largest increase in the exposed area would be in Southern Europe (reaching nearly 60% of the total EU-affected area, compared to 30% today). People affected by droughts would also largely increase from today's levels by a factor of seven, reaching 153 million/year in the Reference simulation. Again, half of the overall population affected would be in the Southern Europe region. The multimodel ensemble projections of more cropland and people affected by drought in the south and the opposite signal in the north are statistically highly significant and robust amongst the Reference simulation members, while the projected changes are more dissonant in a transition zone in between. (Ciscar JC, 2014)
Looking into the same simulation references, forest fires are expected to more than double in Southern Europe, reaching more than 3 times the size of ex-Yugoslavia, almost 800,000 ha. However, if we were to achieve only a 2°C temperature increase, this would be around 400,000 ha, 50% less.
Torrential floods and soil erosion are among the top concerns when looking into the future of Climate Change, which increased or evoked disasters across the south and central Europe. The Balkans, as an integral part of Europe, has already been experiencing this increase in devastating effects, intensity and casualties.
Climate change is projected to largely change the frequency and magnitude of river floods. Flood damages could more than double with the 2080s climate under the Reference simulation, reaching around €11 billion/year. The largest increase would occur in the UK & Ireland and Central Europe South regions. The number of people affected by floods per year could almost double to 290,000. Under the 2°C simulation, the effects would be smaller, with annual economic damage of around €10 billion and 240,000 people/year affected by floods. If the 2080s economy is simulated (i.e. allowing for economic and population growth, instead of shocking the current economy as of today), then the damages would be much greater, reaching €98 billion/year and €68 billion/year under the A1B and E1 scenario, respectively. This difference is due to the much higher value of assets at risk because of economic and demographic developments. (Ciscar JC, 2014)
The adaptation measures to river flooding have been a focal study point in many simulation studies, with the most common objections to maintain a 1 in the 100-year level of flood protection across Europe manageable. However, it is important to note that flood damage simulations are usually subject to a high degree of uncertainty, partly because of the uncertainty in the extreme precipitation projections. The uncertainty of costs can be translated into all economic aspects, however, there is great recurrence that the overall economic costs will be around 2% of the total EU GDP today.
Most of the previous biophysical impacts (barring droughts and habitat suitability) have been integrated into an economic model to assess the effects in terms of household welfare losses. The economic effects consider the direct climate effects (as measured by the biophysical models) and the indirect effects in the economy (as calculated with the general equilibrium economic model). Under the Reference simulation, the annual total damages would be around €190 billion, almost 2% the of EU GDP today. (Ciscar JC, 2014)
Key Terms in this Chapter
Adaptation: In human systems, the process of adjustment to actual or expected climate and its effects, in order to moderate harm or exploit beneficial opportunities. In natural systems, the process of adjustment to actual climate and its effects; human intervention may facilitate adjustment to expected climate.
Runoff: That part of precipitation that does not evaporate and is not transpired but flows through the ground or over the ground surface and returns to bodies of water.
Flood: The overflowing of the normal confines of a stream or other body of water, or the accumulation of water over areas that are not normally submerged. Floods include river (fluvial) floods, flash floods, urban floods, pluvial floods, sewer floods, coastal floods, and glacial lake outburst floods.
Climate Change: A change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings, or to persistent anthropogenic changes in the composition of the atmosphere or in land use.
Drought: A period of abnormally dry weather long enough to cause a serious hydrological imbalance. Drought is a relative term, therefore any discussion in terms of precipitation deficit must refer to the particular precipitation-related activity that is under discussion. For example, shortage of precipitation during the growing season impinges on crop production or ecosystem function in general (due to soil moisture drought, also termed agricultural drought), and during the runoff and percolation season primarily affects water supplies (hydrological drought). Storage changes in soil moisture and groundwater are also affected by increases in actual evapotranspiration in addition to reductions in precipitation. A period with an abnormal precipitation deficit is defined as a meteorological drought. A mega drought is a very lengthy and pervasive drought, lasting much longer than normal, usually a decade or more.
Vulnerability: The propensity or predisposition to be adversely affected.
Afforestation: Any new land being developed as a forest that has not been a forest since 31.12.1982 is considered afforestation.