Hydrogeological investigation of the Kaş Kalkan area and its vicinity

Abstract

n ABSTRACT The present study comprises the hydrogeological investigation at the Kaş-Kalkan research site. The main objectives of this study, are to investigate the hydrogeological structures (features) which may affect and/or control the Karst water resources potential in such coastal region, and to obtain hydrogeological information which might be needed in the planning and implementation of water supplying projects for a near future. in order to achieve these objectives, series of studies and works were carried out in the field and in the laboratory including (1) surface and subsurface geological studies, (2) hydrological regimen characteristics, (3) isotopic analysis of water samples (4) analysis of aerospace images covering the study area, (5) hydrogeological studies in the mainland and along Kaş-Kalkan coastline, (6) In-situ and laboratory works to determine the quality of groundwater in the research site. Most of the lithological units at the research site, belong to the Beydağları Carbonate platform, which is considered as öne of the majör tectonostratigraphic units of the Teke Lycian Taurus, the western limb of the western part of the Outer Taurus Mountains. Study of physiographical and climatic conditions of the Kaş and Kalkan towns is considered as öne of the most important tools for indicating the influence of the site topography on the areal distribution of precipitation, in such coastal karstic region. The inland side of the study area is highly dissected and became rugged due to the intense faulting, folding and different rock weathering. At the research site, there are mainly four majör hydrogeological units. These units were differentiated according to their individual structural and hydrogeological characteristics, into Karstic Lower and Upper Units, Impervious Lower Unit, and the Quaternary deposits (alluvium).inceleme alanında, dört ana hidrojeolojik birim bulunmaktadır. Bu birimler, yapısal ve hidrojeolojik özelliklerine göre Karstik Alt ve Üst Birimler, Geçirimsiz Alt Birim ve Kuvaterner Çökeller (alüvyon) olarak ayırdedilmişlerdir. Yeraltısuyu havzasının beslenimi, başlıca, farklı hidrojeolojik birimlerde süzülen suların hacimsel veya yüzde olarak belirlenmesi şeklinde hesaplanmıştır. Jura-Üst Kretase yaşlı Beydağlan kireçtaşı, Eosen yaşlı Susuzdağ dolomitik kireçtaşı ve Üst Miyosen yaşlı Dirgenler çakıltaşlarmı Otokton geçirimli birimler oluştururlar. Arazi gözlemleri ile jeoloji ve çizgisellik haritalarının karşılaştırıl¬ ması sonucunda, karstik yapıların en yaygın olarak inceleme alanının kuzey ve kuzeybatısında yeraldığı görülmüştür. Burada, fayların kesiştiği bir çok nokta işaretlenmiştir. Buna göre, iç kesimlerdeki fay hatları boyunca farklı karstik yapıların bulunması, aynı zamanda, kıyı akiferine (Beydağlan kireçtaşı) doğru oluşan yeraltısuyu akım yönünü de göstermektedir. Yerinde ve laboratuvarda yapılan yeraltısuyu kalitesi incelemelerin¬ de, inceleme alanındaki yeraltı suyunun kıyı yakınındaki denizsuyu biraz tuzlu olan kaynaklar hariç genellikle içme ve sulama açısından uygun olduğunu göstermektedir.

n ABSTRACT The present study comprises the hydrogeological investigation at the Kaş-Kalkan research site. The main objectives of this study, are to investigate the hydrogeological structures (features) which may affect and/or control the Karst water resources potential in such coastal region, and to obtain hydrogeological information which might be needed in the planning and implementation of water supplying projects for a near future. in order to achieve these objectives, series of studies and works were carried out in the field and in the laboratory including (1) surface and subsurface geological studies, (2) hydrological regimen characteristics, (3) isotopic analysis of water samples (4) analysis of aerospace images covering the study area, (5) hydrogeological studies in the mainland and along Kaş-Kalkan coastline, (6) In-situ and laboratory works to determine the quality of groundwater in the research site. Most of the lithological units at the research site, belong to the Beydağları Carbonate platform, which is considered as öne of the majör tectonostratigraphic units of the Teke Lycian Taurus, the western limb of the western part of the Outer Taurus Mountains. Study of physiographical and climatic conditions of the Kaş and Kalkan towns is considered as öne of the most important tools for indicating the influence of the site topography on the areal distribution of precipitation, in such coastal karstic region. The inland side of the study area is highly dissected and became rugged due to the intense faulting, folding and different rock weathering. At the research site, there are mainly four majör hydrogeological units. These units were differentiated according to their individual structural and hydrogeological characteristics, into Karstic Lower and Upper Units, Impervious Lower Unit, and the Quaternary deposits (alluvium).Recharge of the groundwater basin is calculated depending on the volumetric determination of the water amounts (percentages) that may be infiltrated through different hydrogeologic units. The autochthonous pervious units include the Jurassic-Upper Cretaceous Beydağlan limestone, Eocene Susuzdağ dolomitic limestone, and the Upper Miocene Dirgenler Conglomerates. Comparison of the field observation, geological and lineament maps, has shown that most of the widespread karstic features were located at the northern and northwestern parts of the study area, where most of the intersection of lineaments were plotted. Eventually, the availability of the different Karstic features along the mainland faultlines, may also reflect the main groundwater flow direction through the coastal aquifer (Beydağlan limestone). Insitu and laboratory determinations of groundwater quality suggested that the groundwater of the study area, except the brackish water disharged from the coastal springs, is generally suitable for drinking and agricultural purposes.