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.
Author
- Nima Shokri
Adjunct Professor, Institute for Water, Environment and Health (UNU-INWEH), United Nations University; Technical University of Hamburg
Large sinkholes , some tens of metres wide and deep, have appeared across the Konga 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 collapsed. Sinkhole formation depends on the number of unstable underground structures, not simply on the volume of water extracted.
Land is breaking down
The basin is also experiencing another type of ground deformation, known as land subsidence, in which the surface gradually sinks as underground sediments compact. This can cause cracks in the ground and damage to roads and buildings, although the sinking is often too gradual to notice without satellite measurements.
Satellite radar measurements revealed widespread land subsidence in the area, of up to 90 millimetres per year. Unlike sudden sinkhole collapse, this can develop as groundwater withdrawal increases stress on the land and compresses sediments in the ground.
The problem is not unique to Turkey. A global analysis estimated that over 6.3 million square kilometres of land are subsiding by more than five millimetres annually. The researchers identified groundwater extraction as the most influential factor worldwide.
In Konya, the pressure on groundwater is closely connected to agricultural production . Farmers cultivate crops for established markets and processing industries, often under policies that have favoured high levels of production, rather than water conservation.
Irrigation provides a way for farmers to maintain yields of crops during dry years, but it also allows production to continue at levels that the basin's renewable water supply may not sustain.
However, restricting how much groundwater is extracted without providing support for farmers could impose substantial economic pressure on them, as well as on the nation's food supply. But continued groundwater depletion could progressively undermine the agricultural production that made the region economically important in the first place.
More efficient irrigation could help, but is not enough. If water saved through improved technology is used to expand the area being irrigated, total groundwater consumption may remain unchanged or even increase.
A long-term response would require reliable monitoring of groundwater levels and withdrawals, enforceable extraction limits, agricultural incentives aligned with local water availability and detailed mapping of geological hazards. Satellite measurements can help identify areas under pressure.
The most immediate danger is that another field, road or building may collapse, putting lives at risk.
Preventing the next sinkhole is difficult. The government could address the problem. But it needs to introduce agricultural policies that treat groundwater as a finite resource, rather than a permanent substitute for rainfall.
Nima Shokri is affiliated with Hamburg University of Technology.
