Determining optimum tilt angles of solar surfaces in Sakarya,Turkey     

C.?Aksoy T?rm?k??Email author  C.?Yavuz 《Theoretical and Applied Climatology》2018,132(1-2):15-29

Climate change constitutes a major challenge for high productivity in wheat, the most widely grown crop in Germany. Extreme weather events including dry spells and heat waves, which negatively affect wheat yields, are expected to aggravate in the future. It is crucial to improve the understanding of the spatiotemporal development of such extreme weather events and the respective crop-climate relationships in Germany. Thus, the present study is a first attempt to evaluate the historic development of relevant drought and heat-related extreme weather events from 1901 to 2010 on county level (NUTS-3) in Germany. Three simple drought indices and two simple heat stress indices were used in the analysis. A continuous increase in dry spells over time was observed over the investigated periods from 1901–1930, 1931–1960, 1961–1990 to 2001–2010. Short and medium dry spells, i.e., precipitation-free periods longer than 5 and 8 days, respectively, increased more strongly compared to longer dry spells (longer than 11 days). The heat-related stress indices with maximum temperatures above 25 and 28 °C during critical wheat growth phases showed no significant increase over the first three periods but an especially sharp increase in the final 1991–2010 period with the increases being particularly pronounced in parts of Southwestern Germany. Trend analysis over the entire 110-year period using Mann-Kendall test revealed a significant positive trend for all investigated indices except for heat stress above 25 °C during flowering period. The analysis of county-level yield data from 1981 to 2010 revealed declining spatial yield variability and rather constant temporal yield variability over the three investigated (1981–1990, 1991–2000, and 2001–2010) decades. A clear spatial gradient manifested over time with variability in the West being much smaller than in the east of Germany. Correlating yield variability with the previously analyzed extreme weather indices revealed strong spatiotemporal fluctuations in explanatory power of the different indices over all German counties and the three time periods. Over the 30 years, yield deviations were increasingly well correlated with heat and drought-related indices, with the number of days with maximum temperature above 25 °C during anthesis showing a sharp increase in explanatory power over entire Germany in the final 2001–2010 period.  相似文献   

Ground-Water Contamination by High-Density Immiscible Hydrocarbon Slugs in Gravity-Driven Gravel Aquifers     

M. Yavuz Corapcioglu  M. Akhter Hossain 《Ground water》1990,28(3):403-412

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Cylindrically-Symmetric and Inhomogeneous Cosmological Models with Viscous Fluid     

Can Battal Kilinç  Ilhami Yavuz 《Astrophysics and Space Science》1997,249(1):131-142

In this paper, the Einstein field equations have been solved for cylindrically symmetric and inhomogeneous cosmological models with viscous fluid. Various physical and geometrical properties of the models are also discussed.  相似文献   

Estimation of the responses of axisymmetric bodies in spread irregular waves     

A.P. McCabe  T.J. Stallard  N.J. Baker  H. Yavuz   《Ocean Engineering》2007,34(10):1371-1382

A method is presented of estimating the responses of axisymmetric bodies floating in spread irregular seas, using a Laplace transfer-function formulation of a floating body time-domain model. A general-case spread-wave model is formulated, using separate wave excitation transfer functions, and a simplification of this approach is proposed, reducing both model complexity and computation time. Responses are computed using both approaches and a comparison made to assess the circumstances in which the simplified approach may be used effectively. The results are also interpreted to highlight the implications of using an equivalent unidirectional wave as an approximation to a spread wave.  相似文献   

Heavy metal pollution and acid drainage from the abandoned Balya Pb-Zn sulfide Mine,NW Anatolia,Turkey   总被引：5，自引：0，他引：5  

Atilla?Aykol  Murat?BudakogluEmail author  Mustafa?Kumral  Ali?H.Gultekin  Melih?Turhan  Vildan?Esenli  Fuat?Yavuz  Yuksel?Orgun 《Environmental Geology》2003,45(2):198-208

This study was conducted to determine the effects of the waste-rock dump (WRD) of the underground polymetallic Balya Mine on the Kocacay River and eventually on Lake Manyas in Turkey. Data presented in this paper include geochemical characteristics of various kinds of water (mine, surface and groundwater) and of suspended-particle samples in the vicinity of Balya. The more polluted mine waters have low pH and high conductivity, while high concentrations of Zn, Cd, Mn tend to be found in the dry and wet seasons. High concentrations of Pb, As, Cr, Cu and S appear only in the wet season. The sources of the heavy metal concentration within the Kocacay River are leached waste, surface run off, and overflow from the spillway of the WRD. To minimize the formation of acids and dissolved metal, and for the remediation of the harmful effects of extreme contamination conditions, it is recommended that lime or alkali materials and organic carbon be added to simulate the action of sulfate-reducing bacteria.  相似文献   

Analysis of Cryptosporidium parvum oocyst transport in porous media     

Song‐Bae Kim  M. Yavuz Corapcioglu 《水文研究》2004,18(11):1999-2009

Cryptosporidium parvum is a protozoan parasite, transmitted through aqueous environments in the form of an oocyst. In this study, a transport model into which sorption, filtration and inactivation mechanisms are incorporated is applied to simulate laboratory column data, and the suitability of a kinetic model to describe the C. parvum oocyst transport and removal in porous media is compared with an equilibrium model. The kinetic model is applied to simulate previous column experimental data and successfully simulates the concentration peak; the late time tailing effect appeared in the breakthrough curves, indicating that the kinetic model is more suitable than the equilibrium one at simulating the fate and transport of the oocysts in porous media. Simulation illustrates that sorption causes retardation along with a tailing in the breakthrough curve. Additionally, filtration acts as a major mechanism of removing the oocysts from the aqueous phase, whereas the role of inactivation in reducing the viable oocyst concentration is minimal. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

The role of short-wave troughs on the formation and development of sea-effect snowbands in the western Black Sea     

Yavuz  Veli  Lupo  Anthony R.  Fox  Neil I.  Deniz  Ali 《Theoretical and Applied Climatology》2022,149(1-2):501-510

Theoretical and Applied Climatology - The short waves (less than 6000 km) embedded within the long waves and the resulting short-wave troughs have an effect on the sea-effect snow (SES)....  相似文献   

Multi-proxy records of Quaternary fluvio-lacustrine sediments around Lakes Eymir and Mogan,Ankara (Central Anatolia,Turkey)     

Ceren Küçükuysal  Nurdan Yavuz 《Environmental Earth Sciences》2017,76(16):587

This paper presents the mineralogical, geochemical, palynological and stable isotopic compositions of the Late Pleistocene–Holocene fluvio-lacustrine sediments around Lakes Eymir and Mogan (Ankara), Central Anatolia. It is based on the interpretation of the multi-proxy records in conjunction with the geochronological data in eight different sections. The comparison between the increase/decrease in the abundances of carbonates and total clay assemblages is correlated with the changing abundance of coniferous forests and herbaceous plants (mainly Asteraceae and Chenopodiaceae). δ¹³C and δ¹⁸O values and molecular weathering ratios of the sediments revealing the hydrolysis, evaporation and leaching together with chemical index of alteration (CIA) provide insight into the climatic changes in the study area between 11,899 and 1428 cal year BP. Relatively higher total clay amount, δ¹⁸O of around ?8‰ and higher CIA (>40%) with higher hydrolysis suggest humid conditions during 11,899–6448 cal year BP. Between 6448 and 5763 cal year BP, sediments show oscillations between high and relatively low values of the proxy data implying intercalation of dry and wet seasons. The last period recorded between 5763 and 1428 cal year BP is realized with high calcite precipitation–low total clay and low CIA and relatively higher salinization which directly characterize aridity.  相似文献   

Discussion on "Prediction of ground vibrations resulting from the blasting operations in an open-pit mine by adaptive neuro-fuzzy inference system" by Melih Iphar, Mahmut Yavuz, and Hakan Ak     

Yavuz Karsavran 《Environmental Geology》2009,58(1):227

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Reply to the comment on “Prediction of ground vibrations resulting from the blasting operations in an open pit mine by adaptive neuro-fuzzy inference system” by Tarkan Erdik     

Iphar  Melih  Yavuz  Mahmut  Ak  Hakan 《Environmental Earth Sciences》2009,59(2):473-476

Environmental Earth Sciences -  相似文献