The multidisciplinary study of sediment cores from Laguna Zoñar (37°29′00′′ N, 4°41′22′′ W, 300 m a.s.l., Andalucía, Spain) provides a detailed record of environmental, climatic and anthropogenic changes in a Mediterranean watershed since Medieval times, and an opportunity to evaluate the lake restoration policies during the last decades. The paleohydrological reconstructions show fluctuating lake levels since the end of the Medieval Warm Period (ca. AD 1300) till the late 19th century and a more acute dry period during the late 19th century – early 20th century, after the end of the Little Ice Age. Human activities have played a significant role in Laguna Zoñar hydrological changes since the late 19th century, when the outlet was drained, and particularly in the mid-20th century (till 1982) when the spring waters feeding the lake were diverted for human use. Two main periods of increased human activities in the watershed are recorded in the sediments. The first started with the Christian conquest and colonization of the Guadalquivir River Valley (13th century) particularly after the fall of the Granada Kingdom (15th century). The second one corresponds to the late 19th century when more land was dedicated to olive cultivation. Intensification of soil erosion occurred in the mid-20th century, after the introduction of farm machinery. The lake was declared a protected area in the early 1980s, when some agricultural practices were restricted, and conservation measures implemented. As a consequence, the lake level increased, and some littoral zones were submerged. Pollen indicators reflect this limnological change during the last few decades. Geochemical indicators show a relative decrease in soil erosion, but not changes in the amount of chemical fertilizers reaching the lake. This study provides an opportunity to evaluate the relative significance of human vs. climatic factors in lake hydrology and watershed changes during historical times. Paleolimnological reconstructions should be taken into account by natural resources agencies to better define lake management policies, and to assess the results of restoration policies. 相似文献
The sedimentary basins that dominate the north-eastern Mediterranean (Adana-Cilicia basins in the west and Iskenderun basin
in the east) are located on the flanks of a partly submerged positive structure (a part of the Africa-Eurasia convergence
zone) along which strike-slip faults are evident. This study summarizes the findings of two seismic surveys carried out in
the Alanya-Mersin offshore region. Some 850 km of geophysical survey lines were compiled on these cruises. Based on the results
determined from these surveys, the north and central part of Adana-Cilicia basin can be subdivided into eastern, central and
western structural sub-basins separated by the Ecemiş fault complex in the east and the Anamur-Kormakiti structural high in
the west at the same time. Results of this study also indicate that Ecemiş and Anamur-Kormakiti faults are active. Late Miocene
regional compression was responsible for the compartmentation of this complex into the present arrangement and has initiated
the rotational regime which has governed subsequent tectonic developments, notably the extensional behaviour of the NE-SW
trending Ecemiş and Anamur-Kormakiti faults and the transpressive behaviour of the NNE-SSW trending border fault complex. 相似文献
In this work we study one of the most palaeopedological sequence formed in Central Spain, which is located on the Pliocene–Pleistocene
erosional surface in the Madrid Basin. We also analyse its relationship to erosive and sedimentary Pleistocene events in order
to obtain new data for a correct interpretation of the origin and evolution of forms at the top of tabular lands in this site.
The geomorphic features and the properties of a sequence of very red palaeosols that developed on this old surface can help
us in the understanding of the palaeoclimatic evolution of Central Spain in a Mediterranean climate. They were examined to
identify pedologic and climatic changes during the Quaternary. The soil sequence comprises intercalated palaeoargillic and
palaeopetrocalcic horizons. The clay minerals are mainly illite, kaolinite, smectite and sepiolite. The alternation of argillic
and calcic horizons, limestone debris (cryoclastic colluvions) and aeolian sands suggests succeeding periods of phytostability
and phytoinstability (biostasis/rhexistasis). Argillation, rubification and calcium carbonate accumulation were repeated throughout
the Pleistocene and it is hypothesised that climatic conditions during numerous stages of this period were not very different
from the present conditions. 相似文献
Although much has been written on the subject of ancient Mediterranean harbours, the relatively new area of harbour geoarchaeology remains dispersed in the geoscience and archaeological literature. Over a decade of research has amassed rich and varied datasets of anthropogenically forced coastal evolution, with a remarkable number of between-site analogies. This new research field also shows the rich potential of geoscience to reconcile important archaeological questions. No single publication, however, has yet drawn on these geological patterns to yield a detailed overview suitable for geoscientists and environmental archaeologists. The aim of this review article is to (1) discuss how ancient harbours have come to be preserved in the geological record; (2) expound the basic principles and palaeoenvironmental tools underpinning ancient harbour geoarchaeology; (3) outline some of the most significant research advances made; and (4) discuss a new chrono-stratigraphic model applicable to harbour sequences. 相似文献
In the karstic regions of the Mediterranean coastal zones the groundwater discharge and its outcrops—the coastal and submarine
springs—represent the most typical natural phenomena of littoral karst, the economic potential of which is significant. The
case studies discussed in this paper concern the problems of freshwater tapping in karst coastal zones along the Mediterranean
littoral. Owing to the geological and hydrogeological approach, the set problems and adopted solutions involve two most important
tasks: (1) the regulation of groundwater flow in the tapping facilities and (2) the control system of saltwater encroachment
in a larger protection zone, between the coast and the site of tapping facilities. 相似文献
This paper describes the role of groundwater contribution to surface flow at the Causse d’Aumelas, a karst system near Montpellier
(France), which is traversed by an intermittent river, the Coulazou. A first hydrologic model integrating a digital terrain
model shows the inability of a standard rainfall-runoff model to replicate recorded flood hydrographs. While the flood peaks
are routed through the karstic system along the Coulazou without a phase lag, the peak magnitude is somewhat modified. These
results indicate an initial karst system recharge followed by a significant contribution to surface flow. A hydrodynamic analysis
of ground-water flow confirms these results: the karst system first absorbs part of the rainfall, which induces a general
water table rise within the aquifer, and then contributes to surface flow in the Coulazou. 相似文献
Coastal plumes resulting from the continuous discharge of brackish or fresh river water are common features of continental and shelf seas. They are important for several aspects of the coastal environment, and can influence the local socio-economy to some degree. It is known from many studies that the evolution of plumes depends on various factors, such as the local bathymetry, hydrodynamics and meteorological conditions; most of these works; however, have focused on medium to large-scale rivers, while the smaller-scale discharges commonly found in the microtidal environments of the Mediterranean Sea have been less studied. This paper is centred on the behaviour of a freshwater plume arising from one of such outflows, in terms of both the physical configuration of the waterbody and the characteristics of the main driving mechanisms (discharge rate and wind stress). The modelled cases correspond to an open shallow bay, limited at one end by a large headland, and into which a typical Mediterranean waterway discharges. This particular setup is representative of a number of different bays existing on the Eastern Spanish coast. The numerical results highlight the large influence of the bay's topography on the river plume's extension and inner structure. 相似文献
Ocean and marine ecosystems provide a range of valuable services to humans, including benefits such as carbon sequestration, whose economic value are as yet poorly understood. This paper presents a novel contribution to the valuation of carbon sequestration services in marine ecosystems with an application to the Mediterranean Sea. We combine a state-of-the-art biogeochemical model with various estimates of the social cost of carbon emissions to provide a spatially explicit characterization of the current flow of values that are attributable to the various sequestration processes, including the biological component. Using conservative estimates of the social cost of carbon, we evaluate the carbon sequestration value flows over the entire basin to range between 127 and 1722 million €/year. Values per unit area range from −135 to 1000 €/km2 year, with the exclusive economic zone of some countries acting as net carbon sources. Whereas the contribution of physical processes can be either positive or negative, also depending on the properties of incoming Atlantic water, the contribution of biological processes to the marine “blue carbon” sequestration is always positive, and found to range between 100 to 1500 million €/year for the whole basin. 相似文献
One of the most important challenges for the South East Europe region will be replacing more than 30% of its presently installed fossil fuel generation capacity by the end of 2030, and more than 95% by 2050 if its age structure is considered. This requires a strong policy framework to incentivise new investments in a region currently lacking investors, but also presents an opportunity to shape the electricity sector over the long term according to the broader energy transition strategy of the EU and the Energy Community. The aim of this paper is to assess what type of long-term pathways exist for electricity sector development in the region if they follow the energy transition process of the EU. In this model-based scenario assessment, long term electricity sector futures are explored using a set of interlinked electricity models evaluating the level of renewable energy investment required in the region to reach a deep decarbonization target, assuming emission reduction above 94% by 2050 compared to 1990 in line with the long term market integration and climate policy goals of the EU. It also explores what are the most important system wide impacts of the high deployment of renewable energy concerning generation adequacy and security of supply.
Key policy insights
Energy policies in the South East Europe (SEE) region, both at the national and regional level, should focus on enabling renewable energy integration, as this will be a key component of the future energy mix.
EU and Energy Community policies should be incorporated into national energy planning to ensure that SEE countries embark on the energy transition process at an early stage.
Stranded costs should be carefully considered in decision-making on new fossil-fuel generation and gas network investment in order to avoid lock-in to carbon intensive technologies.
If consistent decarbonization policy prevails, with a significant and persistent CO2 price signal, the role of natural gas remains transitory in the region.
The SEE region offers relatively cheap decarbonization options: the power sector can reduce GHG emissions above 94% by 2050 in the modelled scenarios.