ABSTRACT:The changes in physical, chemical, and mineralogical properties of topsoil after forest fires, and their effect on erosion risk, have been previously studied in different geographical regions and ecosystems. It is well known that the risk of erosion increases after fire due to the loss of shear strength and the changes in hydraulic properties.Consistency limits are strongly related to the shear strength of the soil. Nevertheless, few studies have evaluated the consistency limits of naturally burned soils. In addition, determining the consistency limits of sandy soils can be very challenging due to their low plasticity. The temperatures produced by the forest fire that occurred on the left flank of an irrigation dam in Muğla, Kozağaç village, affected the topsoil. Therefore grain size distribution, soil organic content (SOM), and Atterberg limits of 24 soil specimens collected from the burned and unburned locations were studied. It was found that the grain size distribution of the burned soil did not significantly change, whereas clay content and Atterberg limits increased, and SOM decreased. The methodology followed in this study and the results can serve as a base for future studies of the effect of fire on sandy soils.

ABSTRACT: This study investigated the effects of different post-fire cooling types. Heated rocks were cooled (1) at room temperature to represent natural environmental conditions, (2) below zero to represent cold seasons, and (3) in water to mimic fire fighting scenarios. The study used, 3 different carbonate rocks frequently used as building material; travertine, marble, and limestone. Thin section studies and XRD analyzes were carried out to determine the mineralogical composition of the rocks and the mineralogical changes after the heating-cooling processes; SEM images were used to reveal the microfracture development; and geo-mechanical experiments were conducted to determine the changes in physical and strength properties. After cooling, it was observed that, rather than the formation of new micro- cracks, existing micro-cracks grew. The strength properties of the rocks were more affected by cooling processes than the physical properties, and the lowest strength values were observed after cooling in water. While the tensile strength of travertine and marble decreased 70-80% after sudden cooling, this value did not exceed 30% in limestone containing clay. The results show that rapid cooling generally causes more thermal damage than slow cooling due to the growth of existing micro-cracks; and that cooling has a greater impact on the thermal degradation of rocks than heating, and this effect increases depending on the clay content.

ABSTRACT: This study investigated the causes of the salinization occurring in the Tarsus Coastal Aquifer (Mersin) located in the Eastern Mediterranean region of Turkey. Groundwater salinization, which is a critical problem, especially in the Mediterranean basin, occurs as a result of processes and mechanisms such as seawater intrusion, climate change, geogenic effects and anthropogenic activities (pollution and hydrological interventions). In this context, samples were collected from 87 groundwater wells and seawater (Mediterranean) during a field study conducted in September 2020. The temperature, electrical conductivity, pH, salinity, reduction-oxidation (redox) potential, dissolved oxygen, and total dissolved solid values of collected water samples were measured in the field. The major ion and trace element contents (Ca+2, Mg+2, Na+, K+, HCO3-, CO3-2, Cl-, SO4-2, NO3-, NO2-, B, Br, Sr ve Li) of the water samples were analyzed in a laboratory by spectrometric (ICP-MS), spectrophotometric, and volumetric (titration) methods. Thematic distribution maps of the analyzed parameters were created using a Geographic Information System (GIS) software. The hydrochemical facies of the water samples were determined using Piper and HFE diagrams. In order to explain the salinization mechanisms occurring in the region, binary (x-y) graphs were created using the ratios of various major ions and/or trace elements. According to the results obtained, it was revealed that the salinization phenomenon affecting the Tarsus Coastal Aquifer occurred as a result of seawater intrusion, the dissolution of Messinian evaporites (anhydrite, gypsum and halite) and anthropogenic (agricultural and industrial) activities.

ABSTRACT:This study evaluates, the mass movement that occurred after heavy rains on January 8, 2020 in the Kargıcak district between Km 31+300 and 31+500 of the D-715 highway connecting Silifke and Mut districts. For this purpose, a 2 cm resolution digital surface model and an engineering geological map were first made, using photogrammetric methods from the photographs taken by the unmanned aerial vehicle (UAV). The index and geomechanical parameters of the units were determined by taking disturbed and undisturbed samples obtained from nine boreholes in the area where the landslide occurred. The depth of the sliding surface and velocity of movement were determined using the data acquired from the inclinometers placed on the boreholes. The heavy rains that occurred in the region before January 8, 2020 increased the pore water pressure in the weathered claystone-clay unit outcropping in the landslide area, which in turn caused a decrease in the shear strength of the unit. The Kargicak Landslide started rotationally and developed planarly on the claystone-marl surface with the weathered claystone-clay unit.