Analysis of the Temporal Changes of Inland Ramsar Sites in Turkey Using Google Earth Engine

Dervisoglu, Adalet

doi:10.3390/ijgi10080521

Cited by 17 publications

(11 citation statements)

References 48 publications

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“…• C. According to the data of 249 stations throughout Turkey, the increase in air temperature is about 2 • C in the past thirty-five years [55,56]. In this study and the previous study [4], it was observed that an increase of approximately 2 degrees in temperature over a thirtyfive-year period causes a decrease in inland wetlands. Climate change studies project that temperatures in Turkey will increase by 0.5 to 3.0 • C by 2050, and 0.5 to 4.0 • C by 2100, with an optimistic scenario (RCP 4.5).…”

Section: Resultssupporting

confidence: 60%

“…Each Ramsar site meets at least one of the nine criteria [3] related to wetland types, ecological communities, water birds, fish, and other taxa, that signify international importance. In the previous study [4], all inland Ramsar sites in Turkey were examined from 1985 to 2020, and changes in water surface areas were evaluated on the Google Earth Engine (GEE) cloud computing platform, using Landsat satellite images and the Normalized Difference Water Index (NDWI). Data acquired from the closest meteorological stations to each Ramsar Site were evaluated, and in addition to the meteorological effects, the other factors that may have been causing changes in these areas were also investigated.…”

Section: Introductionmentioning

confidence: 99%

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Investigation of Long and Short-Term Water Surface Area Changes in Coastal Ramsar Sites in Turkey with Google Earth Engine

Dervisoglu

2022

IJGI

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Deltas and lagoons, which contain many flora and fauna, have rich coastal ecological and biological environments, and are wetlands of vital importance for humans. In this study, the current problems in all coastal Ramsar sites in Turkey are summarized, and changes in water surface areas are investigated using Landsat and Sentinel 1/2 satellite images on the Google Earth Engine (GEE) cloud computing platform. Landsat TM and OLI images were used in the long-term analysis, and time series were created by taking annual and July to September averages between 1985 and 2020. In the short-term analysis, monthly averages were determined using Sentinel 2 images between 2016 and 2020. Sentinel-1 Synthetic Aperture Radar (SAR) images were used in the months when optical data were not suitable for use in monthly analysis. The Normalized Difference Water Index (NDWI) was used to extract water surface areas from the optical images. Afterwards, a thresholding process was used for both optical and radar images to determine the changes. The changes were analyzed together with the meteorological data and the information obtained from the management plans and related studies in the literature. Changes in the water surface areas of all coastal Ramsar sites in Turkey were determined from 1985 to 2020 at different rates. There was a decreasing trend in the Goksu and Kızılırmak Deltas, which also have inland wetlands. The decreasing rates from 1985 to 2020 were −24.52% and −2.86%, for annual average water surfaces for the Goksu and Kızılırmak Deltas, respectively, and −21.64% and −6.34% for the dry season averages, respectively. However, Akyatan Lagoon, which also has inland wetlands, showed an increasing trend. Observing the annual average surface area from 1985 to 2020, an increase of 438 ha was seen, corresponding to 7.65%. Every year, there was an increasing trend in the Gediz Delta and Yumurtalık Lagoons, that do not have inland wetlands. The increasing rates from 1985 to 2020 were 46.01% and 17.31% for the annual average surface area, for the Gediz Delta and Yumurtalık Lagoons, respectively, and 38.34% and 21.04% for the dry season average, respectively. The obtained results reveal the importance of using remote sensing methods in formulating strategies for the sustainable management of wetlands.

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Section: Resultssupporting

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Investigation of Long and Short-Term Water Surface Area Changes in Coastal Ramsar Sites in Turkey with Google Earth Engine

Dervisoglu

2022

IJGI

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“…Because of drought and misuse of water resources, half of Türkiye's inland water bodies have lost their ecological and economic qualities for the past 40 years [29]. The main threats to inland water bodies in Türkiye, which are the primary causes of the loss, include unplanned water infrastructure projects such as dams built on rivers feeding lakes, in addition to inter-basin water transfers, excessive irrigation use in agriculture, pollution, illegal hunting and fishing, and other large-scale investments such as highways [30]. The RS data have been used to examine Türkiye's inland water bodies, as well.…”

Section: Introductionmentioning

confidence: 99%

“…Gozukara et al [32] utilized Landsat imageries and determined that Lake Burdur's water level decreased by 13.74 m (−2%) and the lake surface area decreased from 211 km 2 to 130 km 2 (−38.39%) over 42 years (1975-2017). Additionally, Dervisoglu [30] assessed the temporal changes in Türkiye's inland Ramsar sites using Landsat satellite images and the NDWI. It was discovered that inland wetlands declined at varying rates between 1985 and 2020.…”

Section: Introductionmentioning

confidence: 99%

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

Albarqouni

Yagmur

Balçık

et al. 2022

IJGI

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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.

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“…Among the various remote sensing indices, NDWI (Normalized Difference Water Index) is one of the most water practical indices used in many studies to track and predict wetland hydrological changes [37][38][39][40]. In addition, NDVI (Normalized Difference Vegetation Index) has been used as a vegetation indicator to investigate changes in vegetation conditions [33,41].…”

Section: Introductionmentioning

confidence: 99%

The Gavkhouni Wetland Dryness and Its Impact on Air Temperature Variability in the Eastern Part of the Zayandeh-Rud River Basin, Iran

Sara

Yazdanpanah

Nasr-Esfahani

et al. 2022

Water

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The Gavkhouni wetland provides many environmental and economic benefits for the central region of Iran. In recent decades, it has completely dried up several times with substantial impacts on local ecosystems and climate. Remote sensing-based Land Surface Temperature (LST), Normalized Difference Water Index (NDWI) and Normalized Difference Vegetation Index (NDVI) in combination with in-situ data were used to investigate the trend of the Gavkhouni wetland dryness and the associated impact on the variability of local air temperature. The results indicate that the wetland has increasingly experienced drier conditions since the year 2000. The wetland was almost completely dry in 2009, 2011, 2015 and 2017. In addition, the results show that Gavkhouni wetland dryness has a significant impact on local climate, increasing the mean seasonal air temperature by ~1.6 °C and ~1 °C in spring and summer, respectively. Overall, this study shows that remote sensing imagery is a valuable source for monitoring dryness and air temperature variations in the region. Moreover, the results provide a basis for effective water allocation decisions to maintain the hydrological and ecological functionality of the Gavkhouni wetland. Considering that many factors such as latitude, cloud cover, and the direction of prevailing winds affect land surface and air temperatures, it is suggested to use a numerical climate model to improve a regional understanding of the effects of wetland dryness on the surrounding climate.

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Analysis of the Temporal Changes of Inland Ramsar Sites in Turkey Using Google Earth Engine

Cited by 17 publications

References 48 publications

Investigation of Long and Short-Term Water Surface Area Changes in Coastal Ramsar Sites in Turkey with Google Earth Engine

Investigation of Long and Short-Term Water Surface Area Changes in Coastal Ramsar Sites in Turkey with Google Earth Engine

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

The Gavkhouni Wetland Dryness and Its Impact on Air Temperature Variability in the Eastern Part of the Zayandeh-Rud River Basin, Iran

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