The Investigation of Mass Transfer in the Karasu Karstic Aquifer, Konya, Turkey

In this study, the changes in the chemical composition of the groundwater along a flow path were examined by using the water samples collected from unconfined, semi-confined and confined parts of the Karasu karstic aquifer. It was determined that transport of bicarbonate, calcium, and magnesium was dominant in unconfined and semi-confined parts of the aquifer, whereas calcite and dolomite precipitate in the confined parts. On the other hand, gypsum dissolution is present in all parts of the aquifer. In addition, the computed saturation indices explain the occurrences and precipitation of travertines in the Goksu Valley, which is the discharge area for the aquifer. Electronic Publication     

Development of an earthquake loss model for Turkish catastrophe insurance

Following the devastating Kocaeli and Düzce earthquakes of August andNovember 1999, the Turkish Government was faced with an enormousfinancial burden as a result of its statutory obligation to cover the full costsof rebuilding. In order to offset this liability in the future – which has hadan adverse effect on the Government's economic programme – acompulsory earthquake insurance scheme has been introduced for allhouseholders in Turkey. A key element for successful implementation ofthis novel and ambitious programme is the transfer of the earthquake riskabsorbed by the Turkish Catastrophe Insurance Pool (TCIP) to theinternational reinsurance market. An earthquake loss model, described inthis paper, has been developed for the TCIP to serve as a basis for thedecision-making process with respect to the pricing of its insurance policy,risk control, the purchase of reinsurance, and the transfer of seismic risk.Sample results of the loss calculations are presented.     

Critical evaluation of strong motion in Kocaeli and Düzce (Turkey) earthquakes

Turkey was struck by two major events on August 17th and November 12th, 1999. Named Kocaeli (M_w=7.4) and Düzce (M_w=7.2) earthquakes, respectively, the two earthquakes provided the most extensive strong ground motion data set ever recorded in Turkey. The strong motion stations operated by the General Directorate of Disaster Affairs, the Kandilli Observatory and Earthquake Research Institute of Bogazici University and Istanbul Technical University have produced at least 27 strong motion records for the Kocaeli earthquake within 200 km of the fault. Kocaeli earthquake has generated six motions within 20 km of the fault adding significantly to the near-field database of ground motions for M_w>=7.0 strike–slip earthquakes. The paper discusses available strong motion data, studies their attenuation characteristics, analyses time domain, as well as spectral properties such as spectral accelerations with special emphasis on fault normal and fault parallel components and the elastic attenuation parameter, kappa. A simulation of the Kocaeli earthquake using code FINSIM is also presented.     

An evaluation of seismic hazard parameters in southern Turkey

To investigate the characteristics of earthquake hazard parameters as a means of identifying different zones of seismicity, we have compiled a catalogue of about 1850 moderate to large-sized earthquakes with magnitudes m4.0 or greater in southern Turkey for the time period from 1900 to 1990. Several methods have been applied to the earthquake catalogue to assess seismic hazard. The study area is divided into 77 overlapping cells of 2° size. Theoretical calculations were made for the prediction of maximum magnitude, intensity, b-values, strain energy release and corresponding m3 and peak ground acceleration levels for a given period of time. The resultant seismic hazard for each parameter is depicted as a contour map to indicate lateral variations in areas of seismic source. A combination and evaluation of various hazard parameters resulted in more reasonable estimates of hazard. It is found that the most hazardous seismic zones are the Rhodes and Burdur zones where the level of peak ground acceleration reaches up to 280 cm s-2 for an average return period of 100 years.     

Late Quaternary palaeohydrology of the Konya Basin, Turkey, based on isotope studies of modern hydrology and lacustrine carbonates

The Konya plain in south central Anatolia, Turkey, which is now largely dry, was occupied around the time of the Last Glacial Maximum by a fresh-oligosaline lake covering more than 4000 km². Sediment cores from three residual water bodies (Pinarbai, Akgöl and Süleymanhaci) within the larger Pleistocene lake basin, have been analysed using a multidisciplinary approach. The sediment sequences are dated as spanning the last 50 Ka years, although breaks in sedimentation mean that there is only partial chronological overlap between them. Carbon and oxygen isotope analyses on lacustrine carbonate from the three cores give contrasting isotope profiles which reflect the different ages and independent hydrological behaviour of different sub-basins through the late Quaternary. Distinguishing changes that are regional from local effects is aided by modern isotope hydrology studies and by comparing the carbonate ¹³C and ¹⁸O values to diatom and other analyses undertaken on the same cores.     

Plagioclase relations in pelites, central Menderes Massif, Turkey. I. The peristerite gap with coexisting kyanite

Abstract In pelites of the central Menderes Massif, albite and oligoclase with only slight chemical zoning coexist in apparent textural equilibrium in the garnet zone, staurolite zone, and staurolite + kyanite transition zone. The metamorphic temperature range is estimated as approximately 440–550°C (from the Hodges-Spear calibration of the garnet-biotite geo-thermometer), or 440–500°C (Ganguly-Saxena calibration). While oligoclase composition at the peristerite gap changes from An₂₂ to An₁₄, albite also becomes more sodic (An_1,5–An_0.6). The slope of the albite limb is thus the reverse of that reported in other areas, and may not be a true equilibrium feature. Occurrence of kyanite, at temperatures below the crest of the gap, is due to low water activity in the presence of graphite: a H_2o is estimated at approximately 0.1–0.2 from the Na content of muscovite coexisting with albite + kyanite + quartz.     

Evaluating precipitation products for hydrologic modeling over a large river basin in the Midwestern USA

ABSTRACT

We evaluated precipitation estimates, TRMM (Tropical Rainfall Measuring Mission 3B42V7), CFSR (Climate Forecast System Reanalysis), GHCN-D (Global Historical Climatology Network-Daily Version 3.24), and Daymet, using the Soil and Water Assessment Tool (SWAT). The suitability and quality of TRMM, CFSR and Daymet in forcing the SWAT-based hydrological model was examined by means of model calibration. A calibrated TRMM-driven model slightly overestimated streamflow, while a calibrated CFSR-driven model performed worst. The Daymet-driven model performance was as good as the GHCN-D-driven model in reproducing observations. In addition, the temperature was far less sensitive compared with precipitation in driving SWAT. TRMM 3B42V7 showed great potential in streamflow simulation. The results and findings from this study provide new insights into the suitability of precipitation products for hydrological and climate impact studies in large basins, particularly those in typical climates and physiographic settings similar to the Midwestern USA.     

Snow avalanche incidents in north-western Anatolia,Turkey during December 1992

Snow avalanches take place in the mountainous regions of Turkey mostly in the eastern Anatolia Region with an average annual death toll of 23 people and much damage to property. However, in the mountainous areas of the Kastamonu and Sinop provinces in the western part of the Black Sea Region of Turkey between 25 and 30 December 1992, blizzards with heavy snowfall caused roof collapses and major avalanche events whereby 16 people were killed and 2 injured. When past records were investigated, there was no evidence that avalanche accidents had been encountered in the region where the dominant precipitation type is rain in the coastal zones and snow over the mountains. Moreover, avalanche prevention measures are so limited that the resettlement of villages or hamlets located in risk zones is common practice. In this article, avalanche formation associated with the meteorological conditions and geomorphologic features is discussed.This study was partially supported by Tübitak (Scientific and Technical Research Council of Turkey) with Project No. YBAG-0067.     

A process-based classification system for headwater streams

In this paper we develop a classification system for small headwater streams predicated upon an understanding of the dominant physical processes acting in the channel and its basin, and the conditions under which these processes operate. The variables used to build the classification are hillslope gradient, valley width as compared to channel width, channel gradient, channel depth and sediment size. Using physical laws and morphologic relationships, we recognize domains in which various processes dominate. Channels within the same process domain can be expected to behave in a similar manner in transporting sediment and water and responding to and recovering from basin disturbance, therefore we use the domains to recognize distinct channel types. This classification system provides the foundation for building an approach for identifying basins and streams that are comparably sensitive to landuse.     

再论察尔汗盐湖察尔汗二级补给系统S3盐层晶间卤水分异问题

本湖Ｓ_３盐层晶间卤水（简称晶卤）分异与钾盐矿床成因密切相关．察尔汗二级补给系统范围是晶卤分异最复杂的地区，为晶卤钾矿首采区，固、液态钾盐均有可观的储量，因此，深入研究本区晶卤分异问题，有助于进一步理解“阶段性淡化”说全部内容及本区钾盐资源充分利用研究．本文详细列示了晶卤总体、三级补给系统及垂直分异区在平、剖面上的分布，据此，可知其三维空间分布状况，准确预测任意切面、方向及位置晶卤的状态，并就许多问题进行了论述，有一定理论和经济意义．