Turkey’s central Anatolian plateau is one of the country’s most important agricultural regions, producing wheat, maize, sugar beet and other crops. Yet beneath its cultivated fields, the ground is becoming increasingly unstable.
Large sinkholes, some tens of metres wide and deep, have appeared across the Konya basin, swallowing farmland, and threatening nearby roads and settlements.
These collapses can occur suddenly, sometimes in fields that have been cultivated for generations. Around 20 are opening up every year, according to a recent study.
Known locally as obruks, sinkholes are not a new geological phenomenon. They have existed in the Konya basin for thousands of years, but they have become far more frequent over recent decades.
Konya’s sinkholes are consequently both a geological hazard and evidence of a wider water-management problem. The cavities beneath the fields are the product of geological processes extending over thousands of years. Their recent instability, however, is occurring within a groundwater system profoundly altered by human activity and increasingly exposed to drought.
As representatives of countries all over the world prepare to head to Turkey to discuss climate change at the UN’s Cop 31 conference, Ankara continues to grapple with this escalating environmental disaster at home.
The nation’s disaster and emergency management authority (AFAD) has recently documented 684 sinkholes across Konya, Karaman and Aksaray in Turkey’s agricultural heartlands.
Why are they there?
The growing number of sinkholes is often attributed to drought and climate change. But intensive groundwater extraction for agriculture can also increase the risk of collapse.
Decades of intensive agricultural irrigation have altered the conditions beneath the basin’s surface. Groundwater, which is the layer of water below the Earth’s surface, is also not being replenished during long, dry periods, which adds to the problem.
Konya is a closed drainage basin. This means water entering the basin does not flow towards the sea. It is stored underground, and accumulates in lakes and wetlands, or returns to the atmosphere through evaporation and plant transpiration.
Rainfall is relatively low here, and much of it falls outside the main growing season. Groundwater has, therefore, become indispensable to agriculture, particularly for irrigated maize, sugar beet and fodder crops.
The difficulty is that demand for water has grown beyond the rate at which the aquifers, a body of porous rock or sediment saturated with groundwater, can recover. A recent regional study estimated an average annual loss of groundwater storage, equivalent to 3.4 centimetres of water. This figure clearly points to a system under sustained pressure.
Part of the problem is that Turkey experienced its most severe drought for decades in 2025, putting more pressure on farmers.
Farmers often respond by extracting more groundwater, causing underground water levels to fall. This reduces the pressure exerted by water within the pores and fractures of rocks and sediments, potentially destabilising existing underground cavities and increasing the risk of collapse.
The consequences extend beyond water scarcity, because groundwater also puts stress on underground geological formations. The Konya basin contains extensive carbonate rocks, including limestone. Over long periods, groundwater circulating through fractures dissolves minerals and enlarges openings. This process, known as karstification, can produce underground channels, caves and cavities. Sinkholes form when the material above such voids becomes unstable.
Lower groundwater levels can also change the movement of water and sediment through existing underground cavities, allowing loose material to shift downwards. Where the roof of a cavity is already weak, these changes may eventually lead to collapse.
But the response is highly dependent on local conditions. The depth and shape of underground cavities, the thickness and strength of the layers of rock and sediment above them, the distribution of fractures and the history of groundwater fluctuations all matter.
This helps explain an important finding from a study on sinkhole formation in the Konya basin between 2000 and 2024. The researchers identified a sharp increase in the annual formation rate, from approximately three sinkholes a year during 2000-10 to 32 during 2016-19. Yet the rate subsequently declined to around 22 a year after 2020, despite continuing groundwater depletion.
If falling groundwater is responsible, why would fewer sinkholes form while water levels continue to decline? One possible explanation is that the most vulnerable cavities in some areas have already c
Read More
