Most of the large surface reservoirs are stably stratified throughout most or all of the year. One means of assisting in the management is to allow for the selective withdrawal from the reservoir. The value of the intake’s submergence when the upper layer fluids begin to be drawn into the intake is known as “critical submergence”. In this study, the critical submergence for a circular intake pipe in a stratified body is investigated. Experiments were conducted on a vertically flowing downward intake pipe in a still-water reservoir. Experimental results are compared with that of the neuro-fuzzy models. 相似文献
Detailed analysis of the land cover of the Estonian coastal zone is presented based on Estonian laws on coastal zone management,
the CORINE Land Cover (CLC) system, the status of protected areas, and administrative division data of Estonia. By law the
coastal zone is defined as a 200-m wide zone landward from the mean sea level line. The length of the Estonian coastline (including
the islands) is 3794 km. The 200-m zone of the Estonian coast is very diverse. Out of the 34 CORINE land cover types represented
in Estonia 30 are found in the coastal zone. Three dominating land cover types in the coastal zone of Estonia are inland marshes,
coniferous forest and semi-natural grassland. Their total share is 47%; the other 27 land cover types represented here cover
53% of the coastal zone. The Estonian coastal zone is generally in a good natural condition. The proportion of artificial
surfaces throughout the zone is merely 4.7%, while agricultural landscapes cover only ca. 10%. Land cover data for the coastal
zone are also presented by county. Of the 200-m coastal zone 24% is under protection, which is more than twice the value for
Estonia as a whole (11%). Legislative protection of the coastal zone is presently satisfactory. The use of the CORINE Land
Cover system enables comparisons with other European regions since CLC data have been compiled for most of Europe. 相似文献
As environmental problems and pressures on natural resources escalate, awareness building and efforts to protect natural areas have also became a major goal to ensure sustainability. Ecotourism is one of the major activities to protect natural and cultural resources, while also providing economic benefits to both local people and government. Successful ecotourism planning is a function of establishing sound goals and criteria. In this paper, we have presented the example of Igneada, Turkey, as a case to elaborate this point. Igneada a coastal town, located on the north-west Black Sea region of Turkey, was declared a national park in 2007. The park is well known for its longos forests (flooded), lagoons, endemic and endangered species, and wildlife. However, currently, unsustainable economic activities, overgrazing, and urbanization cause threats to its sensitive ecosystems. Promoting ecotourism is a sustainable approach to balance economic, social, and environmental aspects in the development of Igneada.
The aim of this study is to define a set of ecotourism criteria and propose an ecotourism vision for Igneada. The methodology in this research involves field observations and a strengths, weaknesses, opportunities and threats analysis with an Analytical Hierarchy Process. A survey study is conducted with both local people and experts to define a framework to generate a priority ranking for ecotourism-planning decision. The research generated 5 main criteria and 14 subcriteria, among which ‘Proposal of Igneada in Turkey’s 2023 Tourism Strategy Plan’ was the highest ranked opportunity for ecotourism planning and development in the town. 相似文献
This investigation tested the usefulness of geometry-based landscape metrics for monitoring landscapes in a heavily disturbed
environment. Research was carried out in a 75 sq km study area in Saxony, eastern Germany, where the landscape has been affected
by surface mining and agricultural intensification. Landscape metrics were calculated from digital maps (1912, 1944, 1973,
1989) for the entire study area and for subregions (river valleys, plains), which were defined using the original geology
and topography of the region. Correlation and factor analyses were used to select a set of landscape metrics suitable for
landscape monitoring. Little land-use change occurred in the first half of the century, but political decisions and technological
developments led to considerable change later. Metrics showed a similar pattern with almost no change between 1912 and 1944,
but dramatic changes after 1944. Nonparametric statistical methods were used to test whether metrics differed between river
valleys and plains. Significant differences in the metrics for these regions were found in the early maps (1912, 1944), but
these differences were not significant in 1973 or 1989. These findings indicate that anthropogenic influences created a more
homogeneous landscape. 相似文献
Concentrations and areal distribution of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn were determined in the surficial sea bottom sediments along the coastal areas of Istanbul at the southern exit of the Bosphorus Strait, ?stanbul, Turkey. The pollution status of shelf sediments was evaluated by employing pollution indicators (enrichment factors, geo-accumulation, and ecological risk indexes) and sediment quality guidelines (threshold effect level/probable effect level, effect range median (ERM)/effect range low). The results demonstrated that Cd, Cr, Zn, Cu, and Pb were enriched minor to moderate. The net sediment transport patterns show terrestrial inputs in front of the short streams. Another polluted region is at the western margin of the southern Bosphorus exit, where sediment transport is mainly controlled by the secondary currents driven by the Bosphorus jet, and depending on a sand ridge extending offshore. Based on the sediment quality guidelines, Cu, Pb, As, and Cr were likely the most dangerous chemicals to pose environmental risk, and may show toxic biological results. The areal distribution of ecotoxicological index (m-ERM-Q) suggested that 20% of the sediment sample sites fall in the medium–high priority zone and scattered at some specific areas along the coast. 相似文献
In this study, PM10 concentrations and elemental (Al, Fe, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sn, Sb, Ba, Pb, and Bi) contents of particles were determined in Düzce, Turkey. The particulate matter samplings were carried out in the winter and summer seasons simultaneously in both urban and sub-urban sampling sites. The average PM10 concentration measured in the winter season was 86.4 and 27.3 μg/m3, respectively, in the urban and sub-urban sampling sites, while it was measured as 53.2 and 34.7 μg/m3 in the summer season. According to the results, it was observed that the PM10 levels and the element concentrations reached higher levels, especially at the urban sampling site, in the winter season. The positive matrix factorization model (PMF) was applied to the data set for source apportionment. Analysis with the PMF model revealed six factors for both the urban (coal combustion, traffic, oil combustion, industry, biomass combustion, and soil) and sub-urban (industry, oil combustion, traffic, road dust, soil resuspension, domestic heating) sampling sites. Loadings of grouped elements on these factors showed that the major sources of the elements in the atmosphere of Düzce were traffic, fossil fuel combustion, and metal industry-related emissions. 相似文献