Jeoloji Mühendisliği Dergisi

ABSTRACT:In order to reduce the damages caused by the landslides, it is very important to predict the landslide occurrences

and to determine the landslide susceptibility areas by the current methods in the literature. In this respect, it is aimed

to produce landslide susceptibility maps of Ulus district of Bartın where landslides develop in the same lithology.

The important point of the study is that Chebyshev theorem is tested for selected study area in this study and the

susceptibility map produced by this method is compared with the landslide susceptibility map produced by using data A total of 195 landslides were mapped in the study area and two different sampling strategies, Chebyshev’s theorem

and landslide mass were used in the determination of landslide and non-landslide areas. In this study, landslide

susceptibility analysis has been done for the study area by using topographic elevation, aspect, curvature and NDVI

parameters. In the susceptibility analysis using both sampling strategies, Frequency Ratio (FO) method, which is

frequently used in literature, was used and two different susceptibility maps were produced. The performance of the

susceptibility maps was evaluated according to Area Under Curve method (ROC-AUC) and the AUC values were

determined as 0.78 for Chebyshev theorem and 0.72 for the sampling technique according to the number of pixels in

the entire landslide mass, respectively. According to these values, both susceptibility maps were acceptable and the

performance of the susceptibility map produced by sampling with the Chebyshev theorem is relatively higher than

the other sampling method. This result shows that Chebyshev method used in the study is an alternative method that

can be used effectively in landslide susceptibility mapping studies and that the susceptibility map produced by this

method has a successful prediction capacity.

ABSTRACT: A large-scale landslide in an open pit mine located in weathered gneiss unit in Menderes Massif occurred on

19.12.2018. The open pit mine failure occurred on a fairly shallow failure surface (maximum depth: 17 m), running

almost parallel to the slope face. At that time, the overall slope height was 80 meters (elevations: 490 m – 410 m) and

overall slope angle 25°. The failure involved around 700 × 103 m3 of rock. Significant displacements in rock slopes

in the pit occurred before the failure surfaces had fully developed. This study aims to investigate the causes of the

landslide and to monitor slope movements in the landslide area before the failure. While monitoring the movement

(between 2017 and 2018, 750 days), amount of rainfall per day and per hour was also measured and recorded.

The amount of rainfall has been evaluated in conjunction with the time-dependent slope movement data (timedependent

surface displacement measurements) by using the software “GeoMoS” to determine the relationship

between the geological structure and the landslide mechanism. Some small scale instabilities have been observed in

the hanging wall beforehand. The large scale failure of the hanging wall, however, has progressed during the periods

of heavy rainfall, suggesting that the variations in groundwater pressures triggered larger displacements along the

developed failure surface. During dry weather, the slope moved at a rate of about 3.5 mm/day. Slope movement

slightly accelerated in open pit due to the work of third overburden removal at the date of 04.12.2018. Until the

uncontrolled overburden removal at the slope toe (14.12.2018), the amount of the total resultant displacement of

the slope increased up to 100 cm and the rate of slope movement was calculated as 10 cm/day. Finally, from the

uncontrolled excavation of the slope toe (14.12.2018) to 19.12.2018 (when the landslide occurred) the movement

accompanied by the intense rainfall, occurred as 160 cm/day. Total resulting displacement of the slope at the end

of this measurement campaign was at the amount of 10.5 m. In addition, some indicators before the failure were

determined to define the different stages of the landslide. It was also determined that the most important indicators

are the displacements, heaves, and shear-strain accumulation at an elevation near the slope toe.

ABSTRACT: In this study, surface waters and groundwater interactions were investigated at the Attepe-Elmadağ-Menteş-

Karaçat iron fields. The study area takes place in the Menteş upper watershed and the nearby surroundings, which

is located in the Seyhan River main basin. The study area is composed of the metamorphic metacarbonates and

metaclastics, which were subjected to low grade metamorphism in the Precambrian-Ordovician age range. Miocene

conglomerates and current alluviums overlie them with angular unconformity. In the region where the basin is

located, the metacarbonates (recrystallized limestone and dolomites) which are highly fractured, cracked and in

some places have dominantly karstic structure, have been identified as the main aquifer. The Menteş Stream forms

the natural groundwater discharge route and the erosion level of karstification of the aquifer. The faults prevent

the continuity of the karstic aquifer by determining the lateral and vertical positions of other impermeable units. It has been shown that groundwater, recharged with diffuse infiltration by precipitation and a large amount of point

infiltration from the Menteş creek, is shallow circulated young water with a short residence time of 5-10 years. It is

determined that a large part of the Menteş Creek (150-1000 L/s at dry and wet seasons, respectively) disappeared and

added to the Karaçat aquifer. The average flow rate of the Menteş stream was calculated as 474 L/s at the eastern

lower basin exit. The Karaçat aquifer, which also includes Karaçat underground mine quarry, is recharged from

the Menteş Creek rather than neighboring basins. Hydrogeological investigations and isotope data confirmed the

previous work result that there is no flow relation between Attepe lake and Karaçat aquifer.

ABSTRACT: In this study, geological, hydrological, hydrogeological and hydrogeochemical characteristics of Tavas

(Denizli) Plain were investigated in detail. The geological units in the study area were investigated in two groups as

autochthonous and allochthonous and general geological map of the region was prepared. Each lithological unit

is distinguished as permeable, semi-permeable and impermeable units in terms of hydrogeological characteristics

and aquifer potential and a hydrogeological map of the study area has been prepared. In the area, Acıgöl group,

Plio-Quaternary clayey limestone, Plio-Quaternary non-discriminated clastic units, slope debris, Alluvium fan and

Alluvium are porous permeable units; Çameli formation limestone member, Ağaçlı formation, Ortadağ formation,

(Bodrum Nappes, Likya Nappes) are karstic permeable units; Eşme Metamorphics are impermeable units-1;

Marmaris Peridotite (Marmaris Ophiolitic Nappes), Kızılcadağ Melange and olistostrome allochthonous (Marmaris

peridotite Nappes) units are impermeable units-2; and Babadağ formation, Aksu formation, Çamova member and

Gebeciler formation are semi-permeable units. It is determined that the groundwater flow is towards the north-east direction in the plain. In order to determine the hydrogeochemical properties of the groundwater in the study area,

water samples were taken and chemical analyzes were performed. Groundwater in the region are Ca-Mg-HCO3

types. Groundwater is not suitable for human consumption due to limit exceeding As/Mn/Fe/NO3 concentrations.

This is due to the water-rock interactions and/or agricultural activities in the region. It has been determined that

groundwater in the study area can be used as irrigation water.