Changes in the Coastline and Water Level of the Akşehir and Eber Lakes Between 1975 and 2009

Abstract

The Akşehir and Eber Lakes, relatively shallow, small freshwater lakes with an area of 361 km 2 and 150 km 2 and average depth of 7 m and 2 m (1998), respectively in southwestern Turkey, have experienced a severe decline in water levels in recent decades. This study aimed to investigate coastline and water level changes of lakes and identify the causes for the decline in lake levels. Nine Landsat images from different times, monthly temperature, precipitation, discharge, lake level records and population data were used to analyze these changes. From 1975 to 2009, the water surface areas of the Akşehir and Eber Lakes decreased from 356,929 to 126,482 km 2 and from 119,882 to 85,663 km 2 , a loss of 64.5% and 28.4% over the 34-year period, respectively. From 1975 to 2004, the Akşehir Lake level declined by 2.67 m from 956.02 m to 953.35 and the Eber Lake level declined by 2.03 m from 966.75 m to 964.72 m from 1975 to 2004 based on ground lake level data (in situ). The results of the temperature and precipitation analysis showed that although the annual mean climatic factors vary substantially, they show small increasing trend over the record periods. Annual discharge records on the Akarçay River and its tributaries decreased over the basin during the same period. Irrigation systems, three dams and seven pounds built in recent decades for agricultural irrigation and domestic use, made the major impact on lowering the lake levels because they derive water 942 Ü. Yıldırım et al.from the river for human use upstream of the lakes' catchments. Population growth, rising water consumption for agricultural and domestic purposes and building dams has led to lake levels declining. The change of lake levels might depend more on anthropogenic factors than on climatic factors.

The internal seiche field in the changing South Aral Sea (2006–2013)

“…The Aral Sea's desiccation has had an enormous human, ecological and climatic impact (Micklin, 2007;Arashkevich et al, 2009;Zhitina, 2011;Rubinshtein et al, 2014) and has become a paradigm of the large number of lakes all over the world whose water levels have dropped (Bai et al, 2011;Yildirim et al, 2011;Lauwaet et al, 2012;Tourian et al, 2015). The ongoing changes in the Aral Sea are being closely followed by the scientific community (Singh et al, 2012;Schettler et al, 2013;Shi et al, 2014).…”

Characteristics of coastline changes in mainland China since the early 1940s

“…Worldwide coastline changes are characterized by increasing erosion or drastic expansion toward sea due to various environmental processes at the global scale such as climate change and sea level rise (Cooper et al, 2008;Zhuang et al, 2008;Peduzzi et al, 2012), and coastal processes including marine dynamics and local climate variation (Yıldırım et al, 2010;St-hilaire-Gravel et al, 2012;Ranasinghe et al, 2013;Kish and Donoghue, 2013), as well as anthropological activities (i.e., marine reclamation and coastal protection) (Slott et al, 2010;Zhu and Xu, 2012;Mujabar and Chandrasekar, 2013). At least 70% beaches worldwide are in chronic erosion (Dar and Dar, 2009).…”

Declining Trend of Water Inflow in the Dams of Rajasthan State

“…Water inflow in the dams is declining year after year (Rajasthan High Court, 2004). The reason of which may be change in rainfall pattern or change in catchment characteristics (Hassanzadeh et al, 2012;Iglesias et al, 2007;Yıldırım et al, 2011;Risbey et al, 2007). The outcome of this study shows that water inflow in the dams of Rajasthan state is not as per expected inflow.…”