Browsing by Author "Karakus, Huseyin"

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Estimation of Evaporation for Lake Van
(Springer, 2016) Aydin, Harun; Karakus, Huseyin
An evaporation study was conducted at Van Lake, one of the largest soda lakes on Earth, which is located on a high plateau in the Eastern Anatolia region of Turkey. Evaporation on a daily basis for the Gevas, station located at the southeastern shore of the lake was calculated using the Bowen ratio energy budget (BREB), Priestley-Taylor, deBruin-Keijman, Penman, and deBruin methods. The calculated evaporation values were then compared and tested with previously calculated and measured evaporation rates. Compared with available measured evaporation data, the best evaporation estimations (within +/- 0.5 mm/day) were made by the BREB method. The BREB calculations made in this study were statistically significant at the confidence level of 99.9 % for estimation of evaporation at the Gevas, station. Relationships between the calculated BREB evaporations and historical climatic records were also examined to propose a new empirical equation for evaporation estimation for the case of Lake Van. The best regression equation with a coefficient of determination (R-2) of 0.9399 was found between BREB evaporation values and incoming solar radiation (Qs) values. A power regression model proposed to estimate daily evaporation rates from Qs values was statistically significant at the confidence level of 99.9 %. Additionally, a few regression models were also examined to predict the surface water temperature of Lake Van from recorded air temperature. The highest coefficient of determination (0.974) and moderate standard error (3.12 degrees C) values were obtained from a polynomial air-water temperature model. Estimated lake water temperatures using the polynomial model were within +/- 10 % of observed lake water temperatures.
Hnc-Plot: an Excel Vba for Visualization of Helium, Nitrogen and Co2 Isotope Data of Crustal and Mantle Gases
(Springer Heidelberg, 2017) Karakus, Huseyin; Aydin, Harun
We present HNC-Plot, an Excel Visual Basic Application (Excel VBA) that can easily be used to create graphical plots of fluids associated with volcanic gases or geothermal manifestations, based on their helium, nitrogen and CO2 isotope data. HNC-Plot has been designed in a simple way; all the user has to do is to input data in an Excel spreadsheet. The spreadsheet also contains buttons which have links to Excel VBA codes that generate plots. Once, the respective button is clicked, and all required variables are defined, Excel VBA generates a plot with labels and axes. Based upon the user preferences, additional tasks such as construction of mixing lines between mantle and crustal gases or calculation of end-member proportions can also be performed. We sincerely believe geoscientists can quickly and easily create these plots, free of charge, with this application. This study also presents previously published data from related literature to show the foundations of the application and to present sample plots created with it.
A Hydrologic Restoration Attempt of the Dried Akgol Wetland (Central Anatolia, Turkey)
(Springer, 2017) Karakus, Huseyin; Aydin, Harun; Erdem, Osman
The Akgol Wetland has been subject to extensive drainage processes by anthropogenic factors that have almost caused the wetland to disappear since the 1970s. In this contribution, as a one of the pioneering work on wetland restoration in Turkey, we present hydrological studies aiming to restore the natural function of the Akgol wetland and post-restoration observations. Considering the water budget of the wetland, three scenarios focusing on restoring the wetland hydrology were developed. The open water surface area and volumetric water storage relations for each scenario were simulated using GIS-based tools. The most appropriate scenario for restoration of the Akgol Wetland was chosen by taking the original state of the wetland prior to drainage as the primary criterion. As the first stage, functioning of the central channel draining the wetland was ceased by refilling it. Following this, an artificial bank was constructed at the narrowest part of the wetland, which resulted in an open water surface that cover all current and former ponds. The wetland has start to hold surface runoff and groundwater inflows since September 2011. Since rewetting, the Akgol Wetland is regaining its ecosystem functions and the increase in avian population indicate the proposed restoration effort was successful.
The Salinity Problem at Yelkoma Lagoon (yumurtalik-Adana) and Its Restoration by Mixing With Freshwater From Ceyhan River
(Parlar Scientific Publications (p S P), 2015) Aydin, Harun; Karakus, Huseyin; Erdem, Osman
The Yelkoma Lagoon located at Ceyhan River Delta has been significantly deteriorated due to dam construction activities that cause lower freshwater inputs. Compared to the Mediterranean (similar to 40 ppt), high salinity of the Yelkoma Lagoon (up to 116.0 ppt), has adversely affected the ecological life in the lagoon as evidenced by the number of fish deaths. In addition to less freshwater input, high evaporation rates and structure of the inlet channel between the lagoon and the Mediterranean are determined as major causes of high salinities. In this study, we applied End-Member Mixing Analysis to calculate the monthly amount of freshwater that should be contributed from the Ceyhan River to the Yelkoma Lagoon to decrease salinity and ensure sustainability of ecological life and fisheries. As a first stage of the study, a conceptual hydrological model of the Yelkoma Lagoon has been developed based on water volume and its salinity. A bathymetric map of the lagoon was produced allowing measurement of the area and volume of each sector in the lagoon. Monthly salinities were obtained from field surveys for all components of mixing equations. The optimum salinity of the lagoon water has been foreseen to be between the salinity of the Ceyhan River and the Mediterranean. Based on the conceptual model and using a mass balance equation, contributions of saline and freshwater end-members were calculated. As a result of mixing calculations, monthly required flow-rates of freshwater from the Ceyhan River to the Yellcoma Lagoon were determined to be in the range of 0.199 m(3)/s to 3.698 m(3)/s. The calculated freshwater has been given to the lagoon since March 2009, and positive developments have been observed in terms of ecological life.