Lake Burdur Research Articles

A new approach to three-dimensional monitoring of surface changes in lakes: application of three-way data analysis model in Lake Burdur, Turkey.

Lakes are areas of ecological significance that host a wide range of living species. Therefore, monitoring changes in lake surfaces is critical for ecosystem preservation. Since conventional methods based on one-dimensional data analysis have limited capacity to analyze complex systems, they may not always produce the desired results in examining surface change. In this regard, a novel approach based on a three-way analysis model of a multi-temporal dataset was improved for the first time to monitor surface changes in Lake Burdur between 2014 and 2023 in terms of latitude, longitude, and year modes. The newly proposed approach, based on the deconvolution of a multi-temporal data series, provided a new way and an alternative approach with a three-dimensional perspective for the simultaneous prediction of changes in latitude, longitude, and relative quantity profiles of Lake Burdur between 2014 and 2023. The proposed approach is based on the parallel factor analysis (PARAFAC) modeling of the multi-temporal datasets. The change in the lake surface as water levels were monitored from latitudinal and longitudinal profiles was obtained by applying the PARAFAC model to the multi-temporal data array. In the same model, the change in lake water surface over the years was determined from the relative quantity profile. The results obtained from the three-way analysis model were compared with the results provided by the conventional method. It was concluded that the findings of this study could provide valuable information to researchers and policymakers in developing effective strategies to analyze changes in lake surfaces in future studies.

Remote Sensing Application in Water Quality of Lake Burdur, Türkiye

The advancements in space technology have facilitated water quality (WQ) monitoring of lake conditions at a spatial resolution of 10 m by freely accessible Sentinel-2 images. The main aim of this article was to elucidate the necessity of spatiotemporal WQ monitoring of the shrinking Lake Burdur in Türkiye by examining the relation between field and satellite data with a state-of-the-art machine learning- based regression algorithm. This study focuses on detection of algal blooms and WQ parameters, which are chlorophyll-a (Chl-a) and suspended solids (SS). Furthermore, this study leverages the advantage of geographic position of Lake Burdur, located at the overlap of two Sentinel-2 frames, which enables the acquisition of satellite images at a temporal resolution of 2–3 days. The findings enrich the understanding of the lake's dynamic structure by rapidly monitoring the occurrence of algal blooms. High accuracies were achieved for Chl-a (R-squared: 0.93) and SS (R-squared: 0.94) detection.

Comparative evaluation of performances of algae indices, pixel- and object-based machine learning algorithms in mapping floating algal blooms using Sentinel-2 imagery

One of the main threats to freshwater resources is pollution from anthropogenic activities such as rapid urbanization and excessive agricultural nutrient runoff. Remote sensing technologies have been effectively used in monitoring and mapping rapid changes in the marine environment and assessing the overall health of freshwater ecosystems. The main goal of this study is to comparatively evaluate the performance of index-based and classification-based approaches in mapping dense floating algal blooms observed in Lake Burdur using Sentinel-2 imagery. For index-based mapping, algae-specific indices, namely the Floating Algae Index (FAI), Adjusted Floating Algae Index, Surface Algal Blooms Index (SABI), and Algal Blooms Detection Index (ABDI), were used. At the same time, pixel- and object-based Random Forest (RF), eXtreme Gradient Boosting (XGBoost), and Long Short-Term Memory Network (LSTM) were utilized for classification-based algal mapping. For this purpose, seven Sentinel-2 images, selected through time series analysis performed on the Google Earth Engine platform, were used as the primary dataset in the application. The results show that high-density floating algae formations can be detected over 99% by both indices and classification-based approaches, whereas pixel-based classification is more successful in mapping low-density algal blooms. When two-class thematic maps representing water and floating algae classes were considered, the maps produced by index-based FAI using an appropriate threshold value and the classification-based RF algorithm reached an overall accuracy of over 99%. The highest algae density in the lake was observed on July 13, 2021, and was determined to be effective in ~ 45 km2 of the lake’s surface.

Determination of long-term volume change in lakes by integration of UAV and satellite data: the case of Lake Burdur in Türkiye.

Monitoring the water levels and volume changes of lakes and reservoirs enables us to understand the importance of better protection and managing water resources in an ecologically optimum manner. Although some lakes, such as Burdur Lake, are not a source of drinking water, they are home to many endangered animals, endemic plants, and some species. Therefore, monitoring the changes in these lakes over time is important for various reasons. While water level measurement stations in lakes and wetlands provide important information, it may not always be possible to obtain this data. In this study, we investigated the long-term changes in Burdur Lake, a Ramsar site, by integrating the Digital Elevation Model (DEM) obtained by the unmanned aerial vehicle (UAV) with shoreline information obtained from the Landsat mission. This study aimed to investigate the usability, advantages, and disadvantages of the UAV-Landsat integration for volume calculation. As a result, we successfully determined the water level as r= 0.999 and the cumulative volume loss at a rate of 97.5%. Burdur Lake experienced a significant reduction in its area decreasing from 206 to 120 km2 (42%) between 1984 and 2022. Furthermore, the water volume of the lake decreased by 2.70 km3 over a span of 38 years. This study demonstrates the potential and limitations of the presented UAV-remote sensing integration. Our proposed method is beneficial for determining short and long-term water levels and volumetric changes with high accuracy.

Uydu görüntüleri kullanılarak kıyı şeridi değişimi analizi ve gelecekteki konumunun belirlenmesi için etkili bir yaklaşım: Burdur Gölü örneği

Lake shoreline changes can have a significant impact on the biodiversity and ecosystems of wetland. This study was aimed to calculate the coastal change of Lake Burdur in Turkey during the elapsed period from 2013 to 2023. Within this framework both remote sensing based aproach and Digital Shoreline Analysis System (DSAS) was performed using Landsat-7 (TM) and Landsat-8 (OLI) images. To estimate shoreline change rates along the coastal zone, statistical parameters such as End Point Rate (EPR), Linear Regression Rate (LRR), and Net Shoreline Movement (NSM) were calculated. A hybrid algorithm, Normalized Difference Vegetation Index (NDVI) and Tasseled Cap Analysis, is utilized to emphasize the distinction between the lake bodies and coastal zone. The maximum shoreline change in the northeast part of the lake was observed, and it resulted in a change of 543.12 m/yr for EPR and 610.07 m/yr for LRR statistics in the 2013-2023 time period. The lake to land position has only been observed in a small amount which are resulted in for EPR -4.91 m/yr. and -3.17 m/yr for LRR statistics. The lake area decreased from 139 km2 to 118 km2 between 2013 and 2023. The results indicate that if the decision-maker does not measure, the area of the lake will be lost by 14% until 2033 and 27% until 2043.

Long-term spatial-temporal monitoring of eutrophication in Lake Burdur using remote sensing data.

Lake eutrophication continues to be one of the major environmental challenges in lakes worldwide. This study is about using a remote sensing approach to monitor long-term chlorophyll-a (Chl-a) concentrations and the trophic state index (TSI) in Lake Burdur, Türkiye. Surface reflectance from Landsat 5, Landsat 7, and Landsat 8 satellite image collections were evaluated with an empirical equation to estimate a 38-year-long (1984-2021) time series of the lake's median Chl-a concentrations. Pixel quality masking was applied to retain only acceptable quality information and exclude images affected by cloud cover, icing, and other environmental factors from the analysis. The results were analyzed based on annual, seasonal, and monthly temporal averages. Over a period of 38 years, Chl-a concentrations were found to vary between 58.7 and 196.4 mg/m3. Notably higher concentrations were recorded in 2010 and 2021, while lower concentrations were observed between 1991 and 1993. A substantial increase in Chl-a concentration was evident from 2002 to 2010. The maximum concentration of Chl-a during the first two decades of the analysis was 130 mg/m3, which increased to 200 mg/m3 during the last two decades. Landsat-derived TSI values suggested that Lake Burdur has been mostly hypertrophic for the entire study period.

Assessment of Spatio-Temporal Changes in Water Surface Extents and Lake Surface Temperatures Using Google Earth Engine for Lakes Region, Türkiye

This study aims to extract water surface area and lake surface water temperature (LSWT), and to present long-term spatio-temporal analysis of these variables together with meteorological parameters. Three lakes in Türkiye’s Lakes Region, namely, Lake Burdur, Egirdir, and Beysehir, were considered as test sites. The normalized difference water index (NDWI) was applied to Landsat 5 and 8 data from 2000 to 2021 to extract the water extent in the Google Earth Engine (GEE) cloud-based platform. In addition to the lake surface area, Landsat thermal images were used to examine the LSWT. The findings indicated that water pixels could be extracted rather accurately using NDWI, with an overall accuracy of 98%. Between 2000 and 2021, the water surface area value of Lake Burdur decreased by more than 22%, while Lake Egirdir has dropped by less than 4%, and Lake Beysehir has not changed noticeably. LSWT of Burdur and Egirdir Lakes increased by more than 2.13 °C and 0.32 °C, respectively, while it decreased about 1.5 °C for Beysehir Lake. The obtained results were evaluated with meteorological parameters and our findings indicated that human-induced activities were more dominant than climate effects over Lake Burdur, unlike the others.

Spatio-Temporal Assessment of the Shrinking Lake Burdur, Turkey

Water resources in the world are becoming scarce due to both natural climatic conditions under the effect of climate change and human-induced activities. The population is rising day-by-day leading to a steady decrease in water resources, which in turn, highly disturbs the natural ecological functions of the vulnerable systems. Lakes can be addressed as important water bodies that are under the effect of shrinkage in different parts of the world, and if no remedial measures are taken, they will disappear in the near future. Lake Burdur in Turkey is among such lakes that lose its water volume over time. This study was performed via a group of interdisciplinary scientists to analyze the spatial and temporal changes in the water surface area in the long-term (1985-2020) and in the short-term (2016-2020) with the aim of putting forth the areal changes. Remote sensing technology was utilized for this purpose. Landsat imagery and Sentinel 2 images were utilized for the long and short-term assessments, respectively. Meteorological conditions during the inspection terms were obtained from the State Meteorological Service to determine the dominating reason(s) of area changes over time. Natural conditions and anthropogenic activities are linked with the findings. Resultantly, water withdrawals from the dams and reservoirs built in the region and from the streams feeding the lake for irrigation purposes during the dry season represent the human-induced activities dominate over the natural causes of climate change as is the case in most of the water bodies of the world. This outcome was also confirmed by a detailed analysis of the agricultural areas in the basin through satellite images and by field trips made at the site.

Increased Water Abstraction and Climate Change Have Substantial Effect on Morphometry, Salinity, and Biotic Communities in Lakes: Examples from the Semi-Arid Burdur Basin (Turkey)

Global warming and altered precipitation patterns are predicted to intensify the water loss in semi-arid and arid regions, and such regions in Turkey will be particularly affected. Moreover, water abstraction, not least for irrigation purposes, is expected to increase markedly, posing major threats to the water balance of the lakes and thus their biodiversity. Among the closed basins in Turkey, the Burdur Closed Basin (BCB), located in the southwest of Turkey, is expected to be most affected. The BCB includes several types of aquatic ecosystems which support high biodiversity, including one Ramsar site, six Important Bird Areas, and a considerable richness of native and endemic fish species. Therefore, it is essential to analyze the potential environmental impacts of climate change and increased water abstraction on BCB lakes and their biotic communities. Here, we combined historical data on ecosystems as well as meteorological, remote sensing, and ground-truth data to analyze the changes in the temperature and precipitation of the BCB, water surface areas, and land use, as well as the potential effects on waterbird and fish communities. We calculated the water budget to elucidate water availability in the basin over the last few decades and predicted future conditions based on rainfall and temperature forecasts using climate models. The Standardized Precipitation–Evapotranspiration Index (SPEI) was used to relate the water surface area to precipitation and temperature change in the basin. Crop-farming irrigation in the BCB has increased notably since 2004, leading to intensive water abstraction from the lakes and their inflows, as well as from ground water, to meet the increased demand for irrigation. The water abstraction from the lakes, inflows to the lakes, and the groundwater in the basin has increased the water loss in the catchment substantially. Remotely sensed data on lake surface areas showed a major shrinkage of shallow lakes in the last 40 years. Moreover, the largest lake in the basin, Lake Burdur, lost nearly half of its surface area, which is worrisome since the shallower areas are the most suitable for supporting high biodiversity. Climate models (CNRM-ESM2-1GCM for temperature and GFDL-ESM4-GCM for precipitation) suggest that from 2070, the BCB will face long-term, moderate-to-severe dry periods. This, and the increased demand for water for irrigation, along with climate change, may accelerate the drying of these lakes in the near future with devastating effects on the lake ecosystems and their biodiversity.

A stable isotope and functional weed ecology investigation into Chalcolithic cultivation practices in Central Anatolia: Çatalhöyük, Çamlıbel Tarlası and Kuruçay

The integration of stable isotope analysis of crop remains with the ecological analysis of archaeological weed flora allows for a detailed reconstruction of crop husbandry and arable growing conditions. This paper presents the first such study for developed Neolithic and Chalcolithic Central Anatolia, exploring crop husbandry at the large (8 ha) early 6th millennium BC site of Çatalhöyük West and the last phases of the preceding Neolithic Çatalhöyük East, located on the western end of the Konya Plain, and the small 4th millennium sites of Çamlıbel Tarlası (0.25 ha), located in the loop of the Kızılırmak river, and Kuruçay Höyük (~1 ha), located on the shore of Lake Burdur. The results reveal the mosaic nature of Çatalhöyük cultivation; the complex ecosystem, naturally 15N enriched, was additionally anthropogenically improved, while inhabitants also chose to cultivate barley in drier conditions to the wheats and pulses. The smaller, Late Chalcolithic site of Çamlıbel Tarlası cultivated each individual crop species in variable conditions instead of selecting a specific species for cultivation in drier or wetter conditions. Each single species was cultivated in conditions with a wide range of water availabilities while receiving low-level manure application. Variation in water availability is possibly a consequence of the variable topography surrounding the site, with the hills potentially used for cultivation, providing a wide range of conditions due to their slope. Functional weed ecology complements the isotopic data, indicating the wider range of cultivation intensities surrounding Çatalhöyük West, compared with more consistent, narrower ranges of growing conditions at Çamlıbel Tarlası and Kuruçay Höyük. Settlement date, site size and environment seem to be key contributing factors shaping the method used to cultivate crops at these Chalcolithic sites. The larger, earlier community of Çatalhöyük West, located in a complex riverine ecosystem around the dryland anabranching channels of the Çarşamba river, cultivated species in different conditions and maintained a range of crop husbandry intensities, potentially reflecting differential access to limited resources. The smaller Late Chalcolithic sites, with communities consisting of one household to several households and located in less complex ecosystems with higher precipitation, maintained more stable crop growing conditions and management intensities. This is plausibly a consequence of equal access and sharing of critical resources for crop cultivation, such as labour, manure and land, coupled with the adequate precipitation rates.

The Formation and Evaluation of the Faulted Topography in the Burdur Basin, Lakes Region, SW Anatolia

The Burdur Basin, which is located in the Lakes Region in SW Anatolia, was formed by vertical faulting movements. The erosion surfaces were developed on the marl deposit in accordance with the lowering of the base level in each faulting movement in the east of the Burdur Basin. These erosion surfaces are at an elevation of 980, 995, 1040, 1115, 1200, 1300-1340 m on the Neogene marl deposit and knickpoints along the valleys indicate six times depressed along the fault lines of the Burdur Basin. The fault scarp extending on the east of the Burdur Basin was dissected deeply as a triangular facet; the accumulation of materials that had been transported from the highlands led to the formation of dejection fans, cones and re-deposited marl deposit in the eastern part of the Lake Burdur Basin. Earthquakes have occurred frequently since historical times and the subsidence that has taken place in the deeper part of Lake Burdur has attained a depth of more than 70 m in the southern part of the lake which may indicate continued tectonic activity. Lake Burdur, which is the remnant of Neogene Lake, containing some heavy minerals supports the life of only one species of fish and poor flora and fauna.

Potential of global thresholding methods for the identification of surface water resources using Sentinel-2 satellite imagery and normalized difference water index

The aim of this study is to investigate the performance of 15 automatic thresholding methods, namely Huang and Wang’s fuzzy thresholding method, intermode thresholding method, isodata thresholding method, Li and Tam’s thresholding method, maximum entropy thresholding method, mean thresholding method, minimum error thresholding method, minimum thresholding method, moment-preserving thresholding method, Otsu’s thresholding method, percentile (p-tile) thresholding method, Renyi’s entropy thresholding method, Shanbhag’s thresholding method, triangle thresholding method, and Yen’s thresholding method, for mapping water body using Sentinel-2 data based on normalized difference water index. Three different types of surface water bodies, such as a natural lake (Lake Burdur), a dam reservoir (Aslantaş Dam Reservoir), and a part of a river (Aras River), are chosen to reveal the potential of 15 thresholding methods. The reference water body maps of each test site were generated by manual digitization of high-resolution Google Earth images. The thresholding methods were assessed using the statistical measures, namely overall accuracy (OA), Kappa coefficient, producer’s accuracy, user’s accuracy, and misclassification error (ME). The accuracy analyses of 15 thresholding methods were carried out separately for each test site, and then the overall accuracies were calculated to determine the best method. The obtained OA results showed that minimum thresholding method was the best method among these 15 algorithms with 0.0008 ME, 99.92% OA, and 0.9758 Kappa coefficient. On the other hand, Shanbhag’s method provided the lowest overall accuracies as 0.3133 ME, 68.67% OA, and 0.3190 Kappa coefficient.

Burdur Gölü’ndeki seviye değişimi sonucunda ortaya çıkan lakustrin materyalin zamansal ve mekansal değişimi

Türkiye’nin Göller Bölgesinde yer alan ve Ramsar sulak alanı olan Burdur Gölü, son yıllarda dramatik bir şekilde hızla kurumaktadır. Bu çalışmanın amacı; son 42 yılda (1975-2017) Burdur Göl seviyesinin azalması ile bazı iklimsel parametreler arasındaki ilişkiyi değerlendirmek ve karasal ortama çıkan lakustrin materyallerin zamana bağlı konumsal ve alansal dağılımlarını tespit etmektir. Burdur Gölü seviyesinin azalması üzerinde etkisi olan iklim ve diğer faktörler sonucunda; göl seviyesinin 13.74 m alçaldığı (-% 2) ve göl alanının 211 km2’den 130 km2’ye kadar (-% 38.39) gerilediği tespit edilmiştir. Ortaya çıkan lakustrin materyalin konumsal dağılımları ise; daha düşük ortalama eğime (% 0.12) sahip Kuzey Doğu Sahili’nde (KDS) yoğunluk göstermektedir. Burdur Gölü’nün su seviyesinin azalması ile iklimsel parametreler arasındaki ilişki incelendiğinde; göl seviyesindeki azalma ile en güçlü ilişkinin sıcaklık (-0.637**) ve toplam buharlaşma (-0.603**) arasında olduğu tespit edilmiştir. Yıllık toplam yağış miktarı ile göl seviyesinin azalması arasında, herhangi bir ilişki tespit edilememiştir. Bu sonuçlara göre, Burdur Gölü’nün kurumasında etkili olduğu düşünülen iklim faktörlerine müdahale ederek göl havzasının su bilançosu üzerindeki baskının azaltılması pek mümkün görünmemektedir. Bu sebeple Burdur Gölü’nün devamlılığını sağlamak için, hatalı arazi kullanımı ve hatalı tarımsal üretim deseni üzerinde gerekli yasal düzenlemelerin acilen yapılması gerekmektedir.

Participatory Effect of Water Drawdown on Initiation and Propagation of the Ground Cracks South of Lake Burdur (Turkey)

Ground cracks occur in many parts of the globe due to various causes. In Burdur (Turkey), they have been observed on an old alluvial fan encompassing 9 km by 7 km in an area south of Lake Burdur. This 3 m deep crack system continues along a line extending to 850 m, with the largest segment being about 170 m long. Because the cracks are close to a populated area, where damaging earthquakes had occurred in the past, further anxiety is created among the general population as to their source mechanism(s)—particularly if they are related to an imminent earthquake. An accurate mechanism for their occurrence requires resolution of multitude of issues. One aspect not considered to date is the drop in the lake’s water level of about 15 m in the last 25 years. This study focuses on the role of this drop in the lake’s water level. Satellite remote sensing and slope stability analysis methods are used. The results demonstrate significant influence of rapid drop in water level on the occurrence of cracks. The results are also significant for general understanding of the mechanism of occurrence of ground cracks elsewhere in the world.

Water body extraction and change detection using time series: A case study of Lake Burdur, Turkey

In this study, spatiotemporal changes in Lake Burdur from 1987 to 2011 were evaluated using multi-temporal Landsat TM and ETM+ images. Support Vector Machine (SVM) classification and spectral water indexing, including the Normalized Difference Water Index (NDWI), Modified NDWI (MNDWI) and Automated Water Extraction Index (AWEI), were used for extraction of surface water from image data. The spectral and spatial performance of each classifier was compared using Pearson's r, the Structural Similarity Index Measure (SSIM) and the Root Mean Square Error (RMSE). The accuracies of the SVM and satellite-derived indexes were tested using the RMSE. Overall, SVM followed by the MNDWI, NDWI and AWEI yielded the best result among all the techniques in terms of their spectral and spatial quality.Spatiotemporal changes of the lake based on the applied method reveal an intense decreasing trend in surface area between 1987 and 2011, especially from 1987 to 2000, when the lake lost approximately one fifth of its surface area compared to that in 1987. The results show the effectiveness of SVM and MNDWI-based surface water change detection, particularly in identifying changes between specified time intervals.

Subsistence economy and land use strategies in the Burdur province (SW Anatolia) from prehistory to the Byzantine period

A reconstruction of the ancient subsistence economy and land use strategies is presented here for the province of Burdur, more specifically the area south and southeast of Lake Burdur, in southwestern Turkey. This review is based on the results from archaeozoological (including bone collagen carbon and nitrogen stable isotope analyses) and archaeobotanical analyses available from seven sites, dated to distinct time periods ranging from the Neolithic to the Middle Byzantine period. The data (both published and unpublished) are compiled with information available on settlement development and dynamics, in the study area. Results show changing agrarian and animal husbandry practices for a period of more than 8000 years, ranging between self-sustaining economies to specialised husbandry practices and an intensive agricultural exploitation of the landscape, in relation to human settlement activities.

The occurrence and levels of cyanotoxin nodularin from Nodularia spumigena in the alkaline and salty Lake Burdur, Turkey

The occurrence of cyanobacteria species Nodularia spumigena and its toxin nodularin were studied in Burdur Lake, a saline alkaline lake with endemic fauna and a Ramsar site of ornithological importance. The water samples were collected from three different locations of Lake Burdur between May and November of 2011. Abundance of Nodularia spumigena and the nodularin levels peaked at the end of July (112,147 cells mL -1 and 4.82 µg L -1 ), coinciding with the highest levels of chlorophyll a (Chl a ) (27.15 µg L -1 ) and the water temperature (29 o C). Although fish or other animal deaths were not detected during the episodes, it is concluded that N. spumigena blooming should be monitored in Burdur Lake for the ecosystem and environmental health.

Population sizes and migration times of the White-headed Duck, Oxyura leucocephala (Scopoli, 1769), in Turkey

A study on migration times and population sizes of the white-headed duck ( Oxyura leucocephala) , which is one of Europe’s rarest birds, was conducted between January 2007 and August 2010 at Lake Burdur, the Lake Van Basin (Lake Ercek, Lake Sodali (Arin), Lake Norsin) and the Sultan Marshes in Turkey. It was determined that the reason for the species to prefer Lake Burdur as a wintering area was the lack of dense reeds at the share of the lake and not freez completely. The results of our study showed that the maximum individual number was 1220 and an increase in the ratio of adult male during the last years was observed at Lake Burdur. Especially in the recent years, the species was not observed in the Sultan Marshes, because of the habitat degredation. The breeding period was about seven month (April-October) in the Lake Van Basin. During this period it was determined that the species prefers to breed in habitats that have tall and dense reed beds ( Phragmites spp. and Typha spp. ) and which are far from human effects, providing shelter against wind and precipitation.

Geo-Engineering Properties and Swelling Potential of Quaternary Lacustrine Clays in North of Burdur, Turkey

In areas surrounding the city of Burdur, Turkey, where water contents are high, no swelling–shrinkage-dependent deformations are visible because the active zone depth is adjacent to the surface. There are some deformations in areas with low water levels, especially those with low-rise construction. Thus, in some areas around Lake Burdur, increased swelling–shrinkage-dependent deformation is inevitable owing to a steadily decreasing water level of the lake. However, development around Lake Burdur, such as an organized industrial area, a civilian airport, and a military airport currently under construction, exacerbates the problem. Therefore, we examined swelling potentials of lacustrine clay in the active zone within a selected area around lake. Lacustrine soils in the selected area were studied using a hand auger, with a total of 379 samples at 50 points, through depths of 1–3 m. Clayey levels in the research area were separated into three different clay–clayey levels and were analyzed by X-ray diffraction and scanning electron microscope. Results showed that clay minerals at all levels averaged 39–52 % and that most were smectite group clays. Microstructures were plate-like and were aligned face to face. It was also determined that swelling potentials of all examined clayey levels were high to low, with change between 0.22 and 2.59 % and swelling pressures between 2.9 and 71 kPa. Because the water level was close to the surface, so was the active zone; therefore, deformation was noticeable. Swelling–shrinkage-dependent deformations are inevitable in the future with decreasing lake water level.

A 2300-year record of environmental change from SW Anatolia, Lake Burdur, Turkey

This work deals with changes recorded by lacustrine sediments from SW Anatolia in Turkey in the context of increasing stress on the Mediterranean environment in relation to human-climate-environmental interactions. Paleolimnological investigations were carried out on Lake Burdur (Lake District geographical subregion of Turkey), which has been subject to rapid changes in its hydrological system that caused a ~10-m water-level drop in the last 30 years. Study of a 5-m-long sediment core, taken from the recently dried out part of the lake, shows significant variation in granulometry, clay mineralogy, nitrogen and organic carbon content and its isotopic composition (∂13Corg) throughout the sedimentary sequence, which represents the last 2,300 years. Chronology is based on radiocarbon dates obtained from plant fragments. The results provide a record of environmental changes, including biological productivity and erosion intensity, in relation to changes in water level and humidity of the area. The lowest previous water level, which is the same as observed today, occurred at approximately 300 BC, after which time a water-level increase led to a maximum stage between AD 200 and 1200. From AD 1200 to the present, the climate became drier accompanied by an overall lowering of water level, with periods of water-level fluctuations superimposed. The lake never dried out as is observed today at the coring site. The present drop in the lake water level is attributed to human activity rather than to climate change. This record of climate and environmental change in the Lake Burdur area appears to be stratigraphically complete. This study provides rare data for the late Holocene in Anatolia as well as information about rapid climate changes during specific periods. The influence of both the Northern hemisphere atmospheric circulation and Indian monsoon on the east Mediterranean remains unclear. Nevertheless, the North Sea—Caspian atmospheric teleconnection could be an important factor that explains local differences in climatic evolution of Anatolia during the period considered.