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1.
Ocean Dynamics - The Bosphorus, located at the junction of Asia and Europe, controls the transports of water, material, and energy between the Black Sea (BS) and the Mediterranean Sea. The Canal...  相似文献   
2.
A conceptual model with water samples from ten geothermal fields (?smil, Ilg?n (Çavu?cugöl), Tuzlukçu-Ak?ehir, Seydi?ehir and Kavakköy, Hüyük, Ere?li-Akhüyük, Kad?nhan?, Cihanbeyli, Karap?nar and Bey?ehir) in the province of Konya defined the geothermal system. Carbonates, quartzite and marbles of Paleozoic metamorphics are the reservoir rocks and the heating sources are igneous rock intrusions and geothermal gradient. The variable thermal water (CaMgHCO3, CaSO4, NaSO4, CaHCO3, CaNaHCO3, NaCl and CaNaClHCO3) had EC and temperature between 177.8 and 56,100 μS/cm and between 18.3 and 44 °C, respectively. Ca2+ in geothermal fluids are associated with marble and carbonate rocks and the high chloride shows direct connection with deep geothermal system, and prolonged contact with evaporite rocks. Sulphate originates from dissolution of and oxidation of sulphate and sulphur-bearing minerals. The high As, B, F and Mn concentration in some thermal water samples were determined as 85 μg/l, 148.56 mg/l, 3.01 mg/l and 208.13 mg/l, respectively. Reservoir temperatures computed by Na/K geothermometers were between 85.37–158.89 °C for Ak?ehir thermal waters and 58.78–90.45 °C for Ere?li thermal waters. The maximum reservoir temperature of other geothermal waters was 75 °C by the silica geothermometers.  相似文献   
3.
Low-grade schists from the Slavonian Mountains (Tisia Mega-Unit, Mt Papuk, Croatia), previously assigned to Precambrian to Lower Palaeozoic metamorphism, have been subjected to geochemical investigations, P-T modelling, and in situ age dating of monazite. The studied fine-grained metasediments consist of chlorite (5–15 vol.%), K white-mica (40–55 vol.%), quartz (20–35 vol.%), feldspar (albite 15–20 vol.%), opaques (<2 vol.%), and accessory minerals. According to their whole-rock geochemistry, the detritus of the former sediments came from upper crustal felsic rocks as they occur, for instance, at Mt Papuk. The schists show a complex microtectonic fabric, including well-developed schistosity systems. P-T pseudosections in the system MnNCKFMASHTO, constructed for typical schists of the study area, resulted in peak P-T conditions of 445–465 °C and 4.6–6.0 kbar for a sample from Kutjevo (eastern part of the study area) and 450–460 °C and 5.2–6.0 for a Vranovo sample (western part). Electron microprobe (EMP) dating of monazite in the schists gave a weighted average age of 109.0 ± 13.1 Ma (2σ) eventually with three subgroups of ages at 225 ± 63 (two analyses), 114 ± 24 and 83 ± 22 Ma. We conclude that the metamorphism of the studied schists at depths of c. 20 km is due to an Alpine collisional event.  相似文献   
4.
Natural Hazards - In this study, a relief system for a large metropolitan city exposed to serious earthquakes is designed and a top-down approach is applied. Afflicted people’s states and...  相似文献   
5.
We present preliminary statistics on the precipitable water vapor (PWV) content over the Karakaya Hills in Erzurum city, where the largest optical and near-infrared astronomical telescope in Turkey will be operated. Since the observatory will observe in the near-infrared (NIR), it is intended to perform PWV measurements of the atmosphere above the site by using signal delays in Global Positioning System (GPS) communication. The analysis of the GPS data recorded on the summit for almost one year shows that the atmosphere over the site of the observatory, which has an altitude of 3170 m, has favorable conditions for NIR observations. From GPS measurements, we report that the site had an average PWV of 3.2 mm and a median PWV of 2.7 mm between October 6, 2016, and June 15, 2017. We also present the time dependency of the PWV content and the correlations between the amount of PWV and the other meteorological records gathered from radiosonde flights and ground-based measurements.  相似文献   
6.
Because the mixture of seawater and freshwater in the Gyeongin-Ara Waterway in South Korea can lead to the intrusion of saline water into surrounding aquifers, systematic management through the establishment of a groundwater protection area is required. The analytic hierarchy process (AHP) model is used to delineate this protection area based on two primary factors and five secondary factors related to saline water intrusion. The study area is divided into 987 gridded cells with a unit size of 100 × 100 m, and the final evaluation score for each cell is calculated using the AHP model. Consequently, several artificial neural network models based on a multilayer perceptron are developed using the AHP’s secondary criteria and the evaluation score. Comparing the evaluation scores of ANN and AHP, more than 180 samples are required in the ANN model to insure high R2 between the original and estimated values. The ANN model is more consistent than the AHP model when determining groundwater protection area, because it can be re-constructed due to the changes in some secondary criteria and also changed due to a standardization process. The final evaluation score by the ANN model based on 300 samples, with the highest R2, is calculated and the regions with a score higher than 2.0 are selected as the groundwater protection area, accounting for 15% of the total cells. This area is similar to the range within approximately 200 m of the GA Waterway and also includes some changing sites in hydrogeochemistry and electric conductivity, which is produced by saline water intrusion. If the land-use type, groundwater levels, and some other criteria change at any cell, the ANN model can be re-executed to verify whether the cell belongs to a groundwater protection area. Considering that salinity of groundwater near the waterway can be affected by various factors including well depth, pumping conditions, and groundwater levels, the ANN model, which is a non-linear model, can be more effective for prediction than the AHP model.  相似文献   
7.
Saçu  Şehriban  Erdik  Tarkan  Şen  Olgay 《中国海洋工程》2020,34(6):881-888
China Ocean Engineering - Turkey has announced its plan to construct a new waterway, Canal Istanbul, parallel to the Bosphorus. In this study, the influence of Canal Istanbul on salinity...  相似文献   
8.
Despite threats emanating from the influence of climate and non-climate forcing on the barrier island coastal region of southwestern Nigeria, the extent of the coastal erosion is poorly understood. We report evidence of coastal erosion and sediment accumulation in the region over a 34-year period (1973–2017), using Landsat imagery at intervals of approximately six years. Landsat image corrections and various water-extraction algorithms were used to systematically delineate coastal erosion and accumulation in the area. The region was subdivided into western and eastern subregions separated by Lagos Harbour. In the west, erosion took place during the periods 1973–1979, 1979–1984, 1990–1999 and 2005–2011, whereas in the east, erosion occurred during 1973–1979, 1990–1999 and 1999–2005. Coastal sediment accumulation occurred in the east during 1979–1984, 1984–1990, 2005–2011 and 2011–2017, whereas gains in the west occurred during 1984–1990, 1999–2005 and 2011–2017. The study revealed substantial net erosion of 1 228.1 ha in the region as a whole, over the full period. Sediment accumulation accompanying the coastal erosion appears to be linked to longshore drift. Erosion between 1973 and 2011 was probably attributable to climate change (storms and tidal conditions), longshore drift, the inflow and outflow of water at Lagos Harbour, coastal morphology and, possibly, human impacts. However, the coastal changes between 2011 and 2017 were more obviously associated with human activities, such as development of the Eko Atlantic construction project. Coastal surveillance, together with the use of environmentally sensitive protective measures, could possibly help to reduce coastal erosion in the region. Careful coastal management practices, including artificial nourishing and the installation of resilient structures (e.g. seawalls), should be undertaken to protect human settlements that are already at risk from sea-level rise.  相似文献   
9.
We present a study on human perception of map complexity, with the objective of better understanding design decisions that may lead to undesirable levels of complexity in web maps. We compare three complexity metrics to human ratings of complexity obtained through a user survey. Specifically, we use two algorithmic approaches published by others, which measure feature congestion (FC) and subband entropy (SE), as well as our own approach of counting object types rather than individual objects. We compare these metrics with each other as well as with human complexity ratings for three maps of the same area from map providers Google Maps, Bing Maps, and OpenStreetMap. Each map design is assessed at three different scales (levels of detail). We find that (1) the FC and SE metrics appear to be adequate predictors of what humans consider complex; (2) object-type counts are slightly less successful at predicting human-rated complexity, implying that clutter is more important in perceived complexity than diversity of symbology; and (3) generalization choices do impact human complexity ratings. These findings contribute to our understanding of what makes a map complex, with implications for designing maps that are easy to use.  相似文献   
10.
The HAMSOM(Hamburg Shelf Ocean Model),a high-resolution regional ice-ocean coupled model,was applied to investigate the seasonal evolution of Bohai Sea ice for winter 2015/2016.HAM SOM was initialized with monthly climatological temperature and salinity data from WOA13 and driven by hourly meteorological data obtained from the NCEP above the sea surface and tides at the open boundary.The ice model used here is a modified Hibler-type dynamic-thermodynamic sea ice model based upon viscous-plastic rheology.The ice extent,concentration,area,thickness,length of ice season as well as the distance between the top of Liaodong Bay(North China) and the outer ice edge line were simulated and compared with the observed data.Three types of modeling experiments were carried out to investigate the effects of wind,tide,and both wind and tide on Bohai Sea ice.The re sults show that wind,as both a dynamic and a thermodynamic factor,has a significant impact on the ice thickness,ice area,and ice-freezing and ice breakup dates as well as the ice velocity,while tides are a dynamic factor that influences only the ice velocity.During the severe ice period,the wind speed intensity increased by 25%,the average ice thickness thickened by approximately 4.0 cm in Liaodong B ay,approximately 2.1 cm in Bohai B ay and approximately2.5 cm in Laizhou B ay,and the total ice coverage area and total ice actual area increased by about 2×10~4 km~2 and 1.4×10~4 km2,respectively.While the tidal amplitude intensity increased by 25%,the average ice velocity increased by approximately 0.1 m/s.  相似文献   
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