Civil Engineering / İnşaat Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/13
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Article Citation - WoS: 1Citation - Scopus: 1Groundwater Recharge Estiaton in the Alaşehir Sub-Basin Using Hydro-Geochemical Data; Alaşehir Case Study(Springer, 2021) Tonkul, Serhat; Baba, Alper; Şimşek, Celalettin; Demirkesen, Ali CanThe issue of groundwater recharge has gained importance in countries where there is not enough water supply to the aquifer. However, groundwater recharge is a difficult parameter to determine. This difficulty stems from factors such as the location of the area to be studied, time, cost, and hydrological data. Numerical, isotope, and chemical approaches are used in groundwater recharge investigations. Numerical and chemical approaches are more costly and time-consuming than chemical approaches. This study aims to ascertain alluvial aquifer recharge in Alaehir (Manisa) sub-basin using chemical approaches (Chloride Mass Balance Method) and its applicability. For this purpose, research wells were drilled at 25 different points in the alluvial aquifer, water sampling was done in wet and dry periods, and rainwater water samples were collected. Groundwater recharge was calculated by using chemical approaches from the chloride concentrations of the water samples collected. An annual average of 74.84 mm of recharge was found in the Alaehir sub-basin. This value corresponds to 16.38% of annual rainfall. At the same time, it was examined the groundwater and geothermal mixing mechanism to demonstrate the applicability of the Chloride Mass Balance Method. It was concluded that geothermal fluid in Alaehir sub-basin mixed with groundwater at a rate of 17%.Article Citation - WoS: 8Citation - Scopus: 8Estimation Groundwater Total Recharge and Discharge Using Gis-Integrated Water Level Fluctuation Method: a Case Study From the Alasehir Alluvial Aquifer Western Anatolia, Turkey(Springer Verlag, 2020) Şimşek, Celalettin; Demirkesen, Ali Can; Baba, Alper; Kumanlıoğlu, Ahmet; Durukan, Seda; Aksoy, Niyazi; Tayfur, GökmenThe estimation of groundwater recharge is an essential process for hydrogeological study. Realistic determination approach is crucial for assessing groundwater potential in an aquifer system and estimating of groundwater levels and/or changes in dry periods. Based on these matters, we employ a GIS-integrated groundwater level fluctuation method to determine the groundwater recharge for a hydrological period in the Alasehir alluvial aquifer (W. Anatolia). The method basically takes into account both increasing and decreasing of the groundwater levels due to the recharge and discharge mechanisms in the aquifer. In this study, 16 pumping and monitoring wells were drilled with a total depth of 1300 m, and water level data loggers were installed into the monitoring wells to determine the groundwater level changes. The spatial distribution of the monthly groundwater level change map was multiplied by the aquifer storage distribution map and then the accurate water volume is calculated by using the 3-D spatial analysis. According to our evaluation in the aquifer, positive volume change of the groundwater is 187 hm(3) in a year, which is considered as a recharge value of groundwater. It is concluded that the GIS-integrated water table fluctuation method gave rise to estimate the total recharge amount of the groundwater in the Alasehir aquifer. The total groundwater recharge indicates that total inflow in the aquifer from precipitation, leakage from surface water and irrigation waters. It can be stated that the recharge estimation of groundwater in a surficial aquifer, like the Alasehir aquifer, is fairly easy using the GIS-integrated water table fluctuation method.Article Citation - WoS: 2Citation - Scopus: 1Investigation of Groundwater Potential and Groundwater Pollution Risk Using the Multi-Criteria Method: a Case Study (the Alasehir Sub-Basin, Western Turkey)(Springer, 2020) Demirkesen, Ali Can; Budak, Seda; Şimşek, Celalettin; Baba, AlperDetermination of the groundwater potential (GWP) and groundwater pollution risk (GWPR) areas is a very important tool in the semi-arid regions in the world. Like many countries in the world, most of the major settlements in the cities of Turkey are located in permeable alluvial plains. Therefore, significant groundwater pollution is encountered in an alluvial plain containing settlements and industrial sites. This study focuses on the determination of the GWP and GWPR areas in the Alasehir sub-basin, which is one of the economically important districts of the Aegean region, located in the Gediz River basin in western Turkey. In this study, the GWP and the GWPR areas were identified and a GWP index map was generated. The GWP areas in the study basin were determined using different proxies as a multi-criteria method based on geographic information system (GIS) integrated with remote sensing (RS). The result of the study indicates that the most GWP locations in the basin are seen in the west and southeast of the study region. Based on these results, it is understood that the significant GWP and GWPR areas are near the big settlement districts such as Alasehir and Salihli. In particular, the 115-ha organized industrial zone located in the Salihli district is an important factor of the potential for consuming and contaminating water resources. This study method is so important for the selection of both city and industrial areas as well as for regional environmental planning in terms of the GWPR management.Article Citation - WoS: 16Citation - Scopus: 20Groundwater Recharge Estimation Using Hydrus 1d Model in Alaşehir Sub-Basin of Gediz Basin in Turkey(Springer Verlag, 2019) Tonkul, Serhat; Baba, Alper; Şimşek, Celalettin; Durukan, Seda; Demirkesen, Ali Can; Tayfur, GökmenGediz Basin, located in the western part of Turkey constituting 2% land of the country, has an important groundwater potential in the area. Alasehir sub-basin, located in the southeast of the Gediz Basin and subject to the extensive withdrawal for the irrigation, constitutes the study area. Natural recharge to the sub-basin due to precipitation is numerically investigated in this study. For this purpose, 25 research wells, whose depths range from 20 to 50 m, were drilled to observe the recharge and collect the necessary field data for the numerical model. Meteorological data were collected from 3 weather stations installed in the study area. The numerical model HYDRUS was calibrated using the field water content data. Soil characterization was done on the core samples; the aquifer characterization was performed, and the alluvial aquifer recharge due to precipitation was calculated. As a result, the computed recharge value ranges from 21.78 to 68.52 mm, with an average value of 43.09 mm. According to the numerical model, this amount of recharge corresponds to 10% of the amount of annual rainfall.Conference Object Evidence for Sea Water Intrusion in Karstic Aquifer of Karaburun Peninsula, Nw Turkey(International Water Association, 2017) Baba, Alper; Gündüz, Orhan; Şimşek, Celalettin; Elçi, Alper; Murathan, Alim; Sözbilir, HasanKarstic aquifers are considered to be significant sources of groundwater and are mostly under threat due to sea water intrusion in many parts of the world. Seawater intrusion is also a common problem on karstic aquifers of Karaburun Peninsula in north of Mediterranean Region. The hydrogeology of Karaburun Peninsula is fairly complex and is mostly characterized by highly permeable karstic formations with significant water storage in an otherwise water scarce area. The karstic aquifers of the region were recently found to be under severe salt water intrusion, which significantly altered the position of fresh water/sea water interface as a result of excessive pumping and fault zones controlling the karstic network.Conference Object Investigation of Groundwater Recharges Mechanism in Alasehir Plain: From Physical Characterization To Modelling(International Water Association, 2017) Şimşek, Celalettin; Baba, Alper; Aksoy, Niyazi; Demirkıran, Zülfü; Hasözbek, Altuğ; Tayfur, Gökmen; Kumanlıoğlu, Ahmet; Durukan, Seda; Demirkesen, Ali Can; Murathan, Alim; Çağıran, Ömer; Akdeğirmen, Özgün; Tonkul, SerhatCharacteristics of aquifer that allows the flow of groundwater, recharge and discharge mechanism effect the available groundwater potential. In order to determine the available potential of groundwater, the budget components are the most important parameters. In general, different analogical methods are applied in different countries, instead of using measurable data. Determination of the groundwater recharge is the most difficult parameter to be measured among the hydrological budget parameters. In general, the analogical methods are insufficient to determine the groundwater recharge rate. Precipitation, evaporation-transportation and runoff can be measured from the surface meteorological station. However, estimation of groundwater recharge cannot be measured directly. At the moment of climate change, visualization of the spatial distribution of the groundwater recharge estimation and mapping are needed. Therefore, improvements of easy groundwater recharge techniques are very important tools for groundwater basins to develop the water management planning.Conference Object Investigation of sea water intrusion in the Ildırı Region (Çeşme-Turkey) coastal aquifer(Nevşehir Hacı Bektaş Veli Üniversitesi, 2017) Baba, Alper; Gündüz, Orhan; Şimşek, Celalettin; Elçi, Alper; Murathan, Alim; Sözbilir, HasanCoastal aquifers are considered to be significant sources of groundwater and are mostly under threat due to sea water intrusion as a result of anthropogenic (i.e., over exploitation, reduced recharge due to climate change, etc.) and natural sources (i.e., tectonic features and fault line orientations) in many parts of the world. Seawater intrusion is also a common problem on coastal aquifers of Turkey.Conference Object An Integrated Assessment of Water Quality in an Arsenic Containing Aquifer: Milestones From Hydrogeology To Public Health(American Society of Civil Engineers (ASCE), 2012) Gündüz, Orhan; Şimşek, Celalettin; Elçi, Alper; Baba, Alper; Bakar, Çoşkun; Gürleyük, Hakan; Çakır, A.; Mutlu, MerdiyeA multi-disciplinary research is being conducted in Simav Plain, Turkey where an arsenic containing aquifer is at the center of attention. The study is not only aimed to understand the sources and mechanisms of the presence of high arsenic levels in groundwater but also to determine the associated consequences with regards to human health. The high arsenic levels in most groundwater (N=33, avg. 162 ppb), surface water (N=9, avg. 76.6 ppb) and geothermal water (N=3, avg. 406 ppb) samples are strongly related to high occurrences of arsenic in rocks and soils of the plain, which range between 7.1 and 833.9 ppm with an average of 49 ppm. These values correspond to several orders of magnitude higher than international standards and world averages in water and soil, respectively. With this motivation, this research also focuses on human health in the study area associated with exposure to these high arsenic levels via numerous pathways. Consequently, more than 1000 individuals were personally surveyed by public health specialists to determine an inventory of diseases in the area. Furthermore, a verbal autopsy study was also conducted with relatives of the deceased, which were further verified with hospital records, to understand the underlying death cause. As a result, certain cancer rates were found to exceed national averages and the results statistically demonstrated a potential link with high arsenic levels mainly through oral exposure.Conference Object The Use of Cokriging Algorithm for Arsenic Mapping in Groundwater Systems(American Society of Civil Engineers (ASCE), 2012) Gündüz, Orhan; Elçi, Alper; Şimşek, Celalettin; Baba, AlperAccurate mapping of the spatial distribution of arsenic in groundwater is an important but equally difficult task to complete due to a number of uncertainties. Classical univariate interpolation algorithms could sometimes be insufficient to capture high concentration and high gradient areas. Under these circumstances, the use of an auxiliary parameter could provide better estimates of arsenic distribution. Based on this premise, arsenic cokriging with a correlated parameter can improve the performance of interpolation and can enhance the quality of predictions. In order to test this hypothesis, a water quality dataset from an arsenic containing aquifer in Simav Plain, Turkey is used to develop arsenic distribution maps. Arsenic is cokriged with correlated parameters such as manganese, iron and dissolved oxygen; and the results are compared with univariate interpolation algorithms such as ordinary kriging and inverse distance weighing. The comparisons were performed with cross validation at sampling locations and assessed based on mean and root mean squared errors. The results revealed that maps developed using arsenic cokriging with iron have given the smallest error value and have shown closest fit to the extreme values in the dataset. Accordingly, arsenic cokriging with iron is believed to be a promising approach in mapping arsenic distributions in groundwater.Conference Object Investigation of Sea Water Intrusion in Coastal Aquifers: a Case Study From Karaburun Peninsula, Turkey(The International Association for Hydro-Environment Engineering and Research (IAHR), 2015) Baba, Alper; Şimşek, Celalettin; Gündüz, Orhan; Elçi, Alper; Murathan, Alim; Sözbilir, HasanGroundwater is an important natural resource; as of today, more than 2 billion people depend on groundwater. Determination of the quantity of available water resources is crucial due to continuously increasing water demand and unequal spatial distribution of water in the world. Coastal areas are typically considered to be areas of limited supply and large demand and groundwater is mostly the resource that is used for water supply purposes for coastal communities. Thus, there exist numerous studies in literature that focus on the determination of the groundwater characteristics in coastal regions with particular emphasis on the geological, hydrogeological and hydrochemical properties of coastal groundwater. Coastal aquifers are considered to be significant water resources and are mostly under threat due to salt water intrusion. The reason for salt water intrusion is mostly anthropogenic such as over exploitation but occasionally natural causes like tectonic boundaries or fault lines could be influential. When coupled with low recharge rates that are common in semi-arid regions such as the Mediterranean, effective and sustainable supply of water with sufficient quality and quantity becomes a real challenge for coastal communities.