WATER-Model: An Optimal Allocation of Water Resources in Turkey, Syria and Iraq

Political instability of several countries in the Middle East is overshadowing one of the biggest challenges of the upcoming century: Water - a natural resource that is easily taken for granted, but whose scarcity might lead to serious conflicts. This paper investigates an optimal Water Allocation of the Tigris and Euphrates Rivershed by introducing the WATER-Model. A series of scenarios are analyzed to examine the effects of different levels of cooperation for an optimal water allocation. Special emphasize is put on the effects of filling new Turkish reservoirs which can cause additional welfare losses if these actions are not done on a basin-wide coordinated basis. Modeling results show that Turkey is most efficient in its water usage. However, using the water for irrigation purposes in Turkey, instead of the Iraqi or Syrian domestic and industrial sector, decreases the overall welfare. Especially the Euphrates basin might thus encounter losses of up to 33% due to such strategic behaviour. The predicted water demand growth in the region is going to increase this water scarcity further. Minimum flow treaties between riparian countries, however, can help to increase the overall welfare and should therefore be fostered

In-situ stress amplification due to geological factors in tunnels: The case of Pajares tunnels, Spain

Geological and geomechanical anisotropies can significantly increase the magnitude of in-situ stress in a rock mass excavated for tunnelling purposes. Four tunnels for the new high-speed railway lines in Pajares in the Cantabrian Mountains, N. Spain, were analysed and significant deformations was found to have occurred in forty specific zones of these tunnels during excavation, requiring much more support than envisaged before construction. Local factors influencing in-situ stress have been identified in these zones of the tunnels, related to geological structures of high compressive tectonic stress regimes including thrust faults, folds with steep flank dip, orwith geomechanical anisotropies in contact zones between rock formations of different strengths. Amethodological procedurewas applied to four tunnels to assess the influence of the geological anisotropies on the insitu stress magnitudes. This procedure is based on the analysis of tunnel deformations and the support pressure needed to stabilise the excavations affected by geological anisotropies. The increase of in-situ stress due to local factors is expressed by the Stress Amplification Factor (SAF) defined by the ratio between the K(σH/σV)local value estimated in a particular rock mass tunnel zone and the mean K(σH/σV)regional value representative of the whole rock mass tunnel. Kregional was estimated from hydrofracture tests and from the TSI index. Klocal was calculated from the back analysis of the support pressure required to stabilise the deformed tunnel zones. SAF values for the forty specific tunnel zones ranged from 1.1 to 2.5. This significant increase in the magnitude of in-situ stress emphasises the influence of geological and geomechanical anisotropies in tunnel stability and support design. The results provide a quantitative approach for assessing structural stresses in rock masses for tunnelling excavations

Programa de concesiones de la red ferrea nacional colombiana:resumen ejecutivo.

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