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PROBLEM SOLUTION FINAL PAPER

Department of Engineering, TED University

Department of Architecture, TED University

ENG102_SEC06: Expository Writing

Fulya İçöz Narlı

December 24, 2023

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Problem Statement

Sinkholes have been a reality of the central regions of the Anatolian Peninsula for

thousands of years due to the nature of the geography in the region. Karstic rock formations,

which are known for generating sinkholes and similar geographical structures due to their

solubility in water, constitute a very large part of the geography in the area. A sinkhole is a

topographic depression formed when underlying limestone bedrock is dissolved by groundwater

(Encyclopedia Britannica, 2023). They can be less than a meter in width and depth, or they can

be as large as Kızıl Obruk which measures more than 700 meters in length (Dogan & Yilmaz,

2011). Historically, sinkholes mostly kept to the elevated areas of the region in relation with the

comparatively higher groundwater levels of the past; lately however, with the waters receding,

they have begun to appear at lower elevations than ever seen before (Arık et al., 2022). These

depressions occur through either dissolution of the underground limestone formations in carbon

rich water, or a combination of dissolution with gravitational downward movement of the said

material (Gutiérrez et al., 2008).

There are both natural and human induced (anthropogenic) causes of sinkholes formation.

Geographical qualities of the subsurface terrain, volcanic activity of the region and the resultant

release of CO2 and groundwater flow are all considered important natural causes. Karstic rock

formations are comprised of water-soluble materials like limestone, dolomite and gypsum.

Solubility of these materials increases greatly the more acidic the groundwater becomes.

“Acidity primarily derives from CO2 present in the air and in the soil, which slowly dissolves

into the meteoric waters reducing their pH and increasing their corrosion capability” (Gutiérrez
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et al., 2014, para. 7). The faster the ground waters are able solve underground rock formations,

the more the ground hollows out, leading to formation of more sinkholes, faster. Hence, acidity

is an integral part of the processes that form sinkholes. Furthermore, if the water has nowhere to

drain and a supply of fresh water is not present, the present still water eventually gets saturated

with limestone and evaporates and becomes unable to dissolve any more of the rock formation.

Therefore, a consistent water supply and a route for drainage are also necessary. Gradually, as a

result of these processes, a subterranean cave forms. Once the cave becomes large enough to the

point that it is unable to support its own weight anymore, it collapses, creating a new sinkhole.

“Some extend dozens of metres below the surface. Others are shallow recesses” (Joyner, 2022).

Fault lines (which are also present in the area) may also contribute to the collapse. It should be

noted that all of these qualities are present in the region of Central Anatolia, especially in and

around Konya plains.

The greatest of the anthropogenic factors that cause the sinkholes to form in the area is

the general decline of the water table in the area. As water recedes deeper into the earth, ground

water can drain down into lower elevations. This allows sinkholes to form at ever lower grounds

with greater frequency. Excessive agricultural water use, storage for dry seasons, leaks in the

water infrastructure, drainage excavations, vegetation clearance, deforestation, booming

urbanization and intrusive underground mining operations like solution mining negatively affect

the underground water levels in the area (Arık, 2023). An inventory from 1976 shows that out of

more than 6500 sinkholes in Missouri, which has a very similar sinkhole-prone geography,

almost 60% were provoked by artificial processes with the most impactful of these being the de-

stabilization of natural underground drainage channels, causing 52% of the cases with highway
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construction and utilization of explosives also being significant contributors (Williams &

Vineyard, 1976). Engineered structures such as reservoirs and canals are also known to

contribute through altering surface or underground waterways and introducing extra weight on

the ground.

Sinkholes have a vast economic impact in the region of Central Anatolia, especially in

Konya Plain. Sinkholes detected in the area have increased greatly in the past 10 years and in

Konya Basin alone, there are now over 2500 sinkholes confirmed (Joyner, 2022). Some number

of sinkholes collapse instantly without any previous indications. This poses a threat to both

humans and farm animals living in the area, causing economic damage, lower agricultural yields,

injury and fatalities. Some sinkholes are even large enough to swallow entire buildings in this

manner. Farmlands where particularly large and deep sinkholes form are rendered inerrable

indefinitely. Dolines that sink slowly over time – even though they don’t pose a threat to human

life due to their progressive nature- still cause damage to buildings, roads, farmlands, factories

and utility infrastructure like gas, water and electric lines and sewers. Road repairs are especially

expensive as refilling depressions and repaving damaged roads may require substantial amounts

of intensive work for extended periods in remote locations. As ground waters continue to recede,

new sinkholes form ever closer to farmlands and population centers, causing crop loss, damaging

infrastructure and threatening human life; in order to address these issues, there are several

measures that can be implemented.

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Existing Solutions

Sinkholes threaten the lives of humans and livestock alike, damages infrastructure and

causes crop loss. Due to the decrease in subterranean water levels being a major anthropogenic

cause contributing to their recently increased frequency of formation, efficient use of the local

groundwater is considered important. One of the ways to increase the efficiency of water usage is

replacement of old waterways, leaking pipelines and other decaying infrastructure with more

modern systems and equipment. The most comprehensive undertaking currently ongoing in the

area regarding that goal is the “Ereğli – Ivriz Left Bank Irrigation Rehabilitation Project” by DSI,

part of the larger “Irrigation Modernization Project” which encompasses the entire country

(2018). The project seeks to replace the old and deformed network of open waterways and

canals with a more comprehensive, pressurized storage and pipe system which will then be

supported with more advanced methods of crop watering such as drip irrigation. Land

consolidation is also among the goals of the project.

Although long term benefits of the project (if properly implemented) are clear, immediate

effects are limited. It should be clear that a construction project of this magnitude encompassing

the entire plain of Konya has a significant financial burden. Construction itself may take a very

large amount of time which, if not organized very skillfully, may spike said costs even more.

There are also environmental concerns regarding the effects of these construction efforts. Air

quality is expected to drop while the construction efforts are ongoing as dust clouds form due to

the removal and re-laying of the topsoil for pipeline installations and exhaust emissions caused

by large scale operation of heavy machinery for extended periods. Noise and vibrations

generated by those operations may also destabilize the already drought-stricken area and may
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cause additional sinkholes to form. The waste and wastewater of the employed workers have to

be managed carefully to not pollute the environment and the groundwater any further. According

to the report, some loss of agricultural land and animal habitats are also expected, although

aimed to be kept at a minimum. The report also states that there will be no displacements though

resistance and non-compliance with the land acquisition and consolidation efforts may still occur

as seasonal workers and landowners depend economically on the land that may be lost to

construction and significant cooperation with the locals and adequate enforcement is needed.

Arık states in his 2020 interview that only 1/3rd of the water wells in the area are registered with

the DSI (TRT Haber). This statistic clearly demonstrates the current lack of cooperation of the

locals with the state. As discussed in this paragraph, there are numerous short-term effects of the

project and related construction efforts with limited gains for the time being.

Susceptibility and risk assessment is also highly important for planning of future actions,

damage mitigation, transportation of assets and lives away from locations under risk and

avoiding further development of said locations. Sinkhole susceptibility mapping is one of the

most effectives tools scientists have developed with that aim, using advanced scanning

techniques. According to Orhan et al. methods like remote sensing (RS) and geographic

information system (GIS) reinvented the research of damage mitigation due to how effective they

are at collection and assessment of data (2020). AFAD has finalized their mapping efforts this

year with their last report on their “Detection of Sinkhole Fields” project (2023). Project efforts

involve classification and modeling of existent sinkhole formations, updating borders of known

fields with lithological structure capable of generating sinkholes, assessing how and how much
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natural and anthropogenic factors affect sinkhole generation, creating a sinkhole susceptibility

map and developing a response plan accordingly.

Susceptibility mapping and other risk assessment methods are preventative measures.

Preventative measures work exceptionally well when implemented before a problem develops to

be severe enough to cause serious issues or when implemented in anticipation of a problem.

Neither of these are the case in this instance. The fact that the AFAD (Disaster and Emergency

Management Directorate) overseeing this program is indicative enough that this problem in this

region has been allowed to develop into what is now classified as a “disaster” before any

significant action has been taken. The situation is at a point where, as of September 2021, there

were 99 confirmed sinkholes within residential areas and cracks on the ground around 50

centimeters wide were observed (Anadolu Ajansı). The future effectiveness of this solution is

currently uncertain due to the reason that it is entirely dependent on the action plan to be devised

afterwards which is currently yet to be completed. However, with the situation expected to

deteriorate further in the future, a properly devised and well executed action plan may still yield

significant benefits over time.

Suggested Solution One: Reducing Groundwater Usage of the Area

Agriculture is by far the largest user of the global freshwater supply. According to Margat

& van der Gun, 70% of the ground water extracted in the entire world is used for irrigation only

(2013). Encouraging farmers to diversify their crop selection can lessen the impacts of both

sinkholes and climate change on agriculture on top of improving the efficiency of water used.
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Groundwater usage of the region of Central Anatolia can be reduced by substituting water

intensive crops in the area with more water efficient crops, protecting the water table of the

region and therefore reducing the likelihood of sinkholes forming. Research shows that by

replacing the crops used for feeding livestock by agricultural byproducts and using farming

techniques like fallowing (the process of leaving a field unseeded for a season after plowing it),

water usage can be reduced up to 57% while retaining or on some cases even increasing the

economic output of the land (Richter et al., 2023). These gains can then be supported further with

the usage of more efficient irrigation equipment, rainwater harvesting, dynamic scheduling for

irrigation based on weather conditions and recycling and reuse of water. However, hardware is

costly and it is unrealistic to expect farmers to shoulder the financial burden of replacing their

equipment to irrigate entire fields on their own. Government incentives such as subsidies for

replacing traditional irrigation equipment with more efficient alternatives could encourage the

locals to make the switch.

Suggested Solution Two: Stricter Enforcement and Collaboration with Locals

Another solution to reduce the frequency and likelihood of sinkholes forming around

population centers is working more closely with the locals. Awareness can be raised by educating

local communities like farmers and developers about dangers related to sinkholes and

responsible land use and proper planning can be promoted that way. Meetings, workshops and

seminars can be prepared for these purposes. Strengthening regulations and effective

enforcement is also required. The staggering amount of illegal water wells in the area shows how

out of control the situation currently is. By designing and enforcing laws and guidelines suitable

to the unique needs of the area, groundwater usage of the area can be better monitored, economic
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and agricultural losses lessened, development of sinkhole-prone zones may be restricted,

construction of expensive infrastructure such as roads and utility lines in risky areas may be

avoided altogether, impacts of heavy machinery operations like mining lessened and quality of

the structures built can be better ensured to withstand the circumstances.

Conclusion

Sinkholes have always been a regular occurrence in the karstic regions around the world,

one of which is the region of Central Anatolia. There are both natural and anthropogenic causes

of sinkhole formation with natural causes being more prominent. However, with population

increasing, demand for water in the area has increased as well which resulted in the water table

dropping and this dramatically exacerbated the problem. The Turkish Government already

acknowledges the issue and is working on multiple projects to solve it. Still, these solutions are

either too costly financially or are not expected to make any substantial impact in the near future,

therefore further action is required. Given the existing solutions for this problem, we have

decided on two additional solutions that stood out to support the already ongoing efforts.

Reducing the amount of water used for irrigating the vast farmlands in the region should help the

water table recover, reducing the quantity of newly formed sinkholes back to historical levels.

Collaborating and educating the locals and enforcing stricter regulations should help keep the

water use in check, reduce economic and infrastructural damage, reduce the risk of fatal

accidents and encourage proper land use. This recent and substantial increase in the frequency of

sinkhole formation is an important issue, threatening population centers, the production of food,

economic stability, infrastructure, human and animal lives, and action should be taken so that a

sustainable future for the region can be created.

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REFERENCES

AFAD. (2023, August 24). Obruk Alanlarinin Tespit Edilmesi Projesinde Son Aşamaya Gelindi-

BASIN BÜLTENİ [Press release]. https://www.afad.gov.tr/obruk-alanlarinin-tespit-

edilmesi-projesinde-son-asamaya-gelindi-basin-bulteni

Anadolu Ajansı. (2021, September 27). Konya Ovası’nda yüzey yarıklarında artış yaşanıyor.

https://www.aa.com.tr. Retrieved December 3, 2023, from

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Arık, F. (2023). Dünya’da ve Türkiye’de Obruk Oluşumları: Tanım, Sınıflandırma Ve Oluşum

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Devlet Su İşleri [DSI]. (2018). IRRIGATION MODERNIZATION PROJECT (P158418)

EREĞLİ – IVRIZ LEFT BANK IRRIGATION REHABILITATION PROJECT

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