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Intensive sand mining puts river systems in peril

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By Eng. Thushara Dissanayake

sand is an essential aggregate material used for construction work. After 2004, Sri Lanka experienced a boom in the construction industry due to rehabilitation the tsunami-hit infrastructure in the country, creating a huge demand for sand. Even later, demand increased exponentially in tune with the expansion of construction activities such as roads, condominiums, and other mega projects during the post-war period.

While there appears to be no dearth of sand, not all sands are suitable for construction work as the properties of the sand matters a lot to maintain the accepted standards. Sand should be clean, devoid of problematic chemicals, and conform to required sizing to be used in construction activities.

In Sri Lanka, sand is mainly obtained from river beds. Being a readily available raw material, it requires no processing at all, in most cases. However, it is now well obvious that continued and indiscriminate sand mining has caused irreparable damage to the ecological and physical environments of our river systems. The Kelani Ganga, the Kalu Ganga, the Deduru Oya, and the Maha Oya have suffered the worst damage.

Attention paid to the issue of overexploitation of river sand seems to be inadequate at present. As a result, rivers have been adversely affected, and this has led to many physical, ecological, and socio-environmental impacts. River bed and bank erosion often damaging riverine structures, loss of biodiversity, lowering of groundwater table and water pollution are some of severe impacts caused by indiscriminate sand mining.

 

Sand budget

The main impact of sand mining is the altering of the sediment budget of the river. Besides, it affects the river hydraulics. The geological replenishment process takes a considerable time period.

Meanwhile, many reservoirs were constructed in our river basins in the recent past. This has further aggravated the situation. These reservoirs limit downstream sand availability as sand is trapped in the reservoirs as sediments.

 

Physical Impacts

Large-scale river bed lowering due to sand mining can increase bank height and aggravate bank collapse due to undercutting. This scenario endangers adjacent lands and structures. Further, lowered main stream bed triggers tributary stream bed erosion. Thus, lowering of riverbed sometimes goes beyond the sea level as in the case of the stretch of the Kelani Ganga beyond Hanwella. As a result, drinking water intakes, located in rivers close to the sea mouth, are affected by saline water intrusion into freshwater. The Ambatale water intake in Kelani Ganga is an example and sophisticated remedial works are imperative for controlling the salinity issue.

 

Groundwater

Lowering of riverbed due to sand mining drops the river water level as well. Eventually, the water table in the adjacent land area also goes down. This is a serious problem for groundwater users as the water level of their domestic wells falls in parallel with the water level of the river. Low groundwater levels can also affect vegetation in floodplains and adjacent wetlands, which are important components of riverine ecology.

 

Stability of structures

When sand mining is done at a certain location the river bed erosion tends to migrate upstream to cover up the supply deficiency. During high flows, the bed erosion extends to downstream as well. Thus, the erosion of bed and banks is not limited to the area of mining but affects a considerable distance to the upstream and downstream of the river. This scenario adversely affects most of the riverine structures, especially bridges. A classic example is the Badalagama Bridge across the Ma Oya; its foundation is exposed (see picture). During the recent floods, one abutment collapsed.

 

Flora and fauna

From an ecosystem perspective, sand is an important abiotic component, which provides habitat for many aquatic animals. Riparian and instream vegetation are integral components of the river ecosystems. Further, the woody debris in aquatic ecosystems is an important habitat and spawning site for many aquatic animals. The dragonfly preys on mosquitoes. Hence, it is a beneficial insect as far as the present dengue menace in the country is concerned. Nevertheless, the sand extraction process destroys dragonfly nymphs before they emerge from riverine habitats in adult form.

 

Flooding

With the lowering of river bed, river water levels go down reducing overbank flooding during high flows. This in turn reduces the supply of rich organic matter to flood plain wetlands. In addition, it aggravates downstream flooding, as water storage in the floodplain is limited.

 

Water quality

The content of suspended particles in the water column rises as a result of sand mining operations.

The high concentration of suspended particles in water blocks the respiratory system of fishes and other aquatic species endangering their lives. Similarly, it affects respiration and photosynthesis of instream flora, and they, in turn, lead to reduced growth rate and finally its total destruction. When the river water is used for drinking, additional purification efforts have to be made to remove the turbidity.

 

Coastal erosion

The conveyance of sand to the shoreline by the rivers is also very important. The sand deposited at the shoreline is gradually moved along the coast by waves and it is a nourishment for beaches. When the sediment supply to the coastal environments decreases, undernourished beaches suffer erosion. Some areas in the eastern coastal zone of the country survived the Tsunami in 2004 due to such sand dunes.

 

Present regulations on sand mining

River sand mining is a lucrative business activity in the country. However, it is reported that almost one-third of the total sand supply to the country is from illegal sources. According to Mines and Minerals Act No. 33 (1992) of Sri Lanka sand is a property of the state and a permit is required to mine and transport. The Geological Surveys and Mines Bureau (GSMB) is responsible for identifying locations and quantities of available sand deposits. Further, this mining and transportation process should be in line with the National Environmental Act and laws and regulations of other relevant line agencies. Unfortunately, illegal sand mining taking place at a massive scale is yet to be controlled effectively.

 

Alternative sources for sand

Restricting sand mining from riverbeds due to aforesaid environmental issues will adversely affect the construction industry as the present supply is hardly enough to meet the ever-increasing demand. Therefore, it is very important to focus on alternative sources.

Land-sand and manufactured sand are the best alternatives to river sand. It is the sand extracted from earth containing a higher percentage of sand by washing. Manufactured sand is obtained mainly by recycling demolished building material and by crushing rock. However, the degree to which manufactured sand can replace natural sand depends on the quality of processing and cost. Appropriate policies are to be developed for promoting these alternative sand sources.

We have thousands of ancient irrigation tanks throughout the country. Most have been silted to a considerable level limiting their water storage capacity. Often, desilting of these tanks is not promoted owing to high cost. In many tanks, the deposited materials are rich in sand. These silt deposits can be excavated and used as a source of sand under appropriate environmental regulations. Thereby, it is possible to increase the water storage capacity of these tanks as well.

Off-shore sand is another alternative source for sand though not suitable for immediate use due to high salinity. In order to prevent environmental damage to the coastal zone, sand has to be pumped from a distance of about 10 km from the shore. This sand can be used for construction works after removing the salt content. Still, artificial methods of washing out are costly. As a natural method, sand can be exposed to rain for a period of six months and this is sufficient to make it usable, according to studies carried out by the Moratuwa University.

 

Sand conservation as an option

Conservation is another important strategy to limit sand demand. Following actions are beneficial to minimise sand requirements and promote its optimal utilisation.

= Use river sand as a raw material only for construction works and not for landfilling or similar land improvement activities

=Adaptation of new construction technologies that minimise the use of sand

=Quantification of river sand replenishment rates and issuing mining permits accordingly.

It has to be taken into account that the global construction industry is set to grow by more than 70% by 2025, and contribution from our country to it will not be much less than that.

(The writer is a Chartered Engineer

specialized in water resources with over 20 years experience)



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Features

Ranking public services with AI — A roadmap to reviving institutions like SriLankan Airlines

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Efficacy measures an organisation’s capacity to achieve its mission and intended outcomes under planned or optimal conditions. It differs from efficiency, which focuses on achieving objectives with minimal resources, and effectiveness, which evaluates results in real-world conditions. Today, modern AI tools, using publicly available data, enable objective assessment of the efficacy of Sri Lanka’s government institutions.

Among key public bodies, the Supreme Court of Sri Lanka emerges as the most efficacious, outperforming the Department of Inland Revenue, Sri Lanka Customs, the Election Commission, and Parliament. In the financial and regulatory sector, the Central Bank of Sri Lanka (CBSL) ranks highest, ahead of the Securities and Exchange Commission, the Public Utilities Commission, the Telecommunications Regulatory Commission, the Insurance Regulatory Commission, and the Sri Lanka Standards Institution.

Among state-owned enterprises, the Sri Lanka Ports Authority (SLPA) leads in efficacy, followed by Bank of Ceylon and People’s Bank. Other institutions assessed included the State Pharmaceuticals Corporation, the National Water Supply and Drainage Board, the Ceylon Electricity Board, the Ceylon Petroleum Corporation, and the Sri Lanka Transport Board. At the lower end of the spectrum were Lanka Sathosa and Sri Lankan Airlines, highlighting a critical challenge for the national economy.

Sri Lankan Airlines, consistently ranked at the bottom, has long been a financial drain. Despite successive governments’ reform attempts, sustainable solutions remain elusive.

Globally, the most profitable airlines operate as highly integrated, technology-enabled ecosystems rather than as fragmented departments. Operations, finance, fleet management, route planning, engineering, marketing, and customer service are closely coordinated, sharing real-time data to maximise efficiency, safety, and profitability.

The challenge for Sri Lankan Airlines is structural. Its operations are fragmented, overly hierarchical, and poorly aligned. Simply replacing the CEO or senior leadership will not address these deep-seated weaknesses. What the airline needs is a cohesive, integrated organisational ecosystem that leverages technology for cross-functional planning and real-time decision-making.

The government must urgently consider restructuring Sri Lankan Airlines to encourage:

=Joint planning across operational divisions

=Data-driven, evidence-based decision-making

=Continuous cross-functional consultation

=Collaborative strategic decisions on route rationalisation, fleet renewal, partnerships, and cost management, rather than exclusive top-down mandates

Sustainable reform requires systemic change. Without modernised organisational structures, stronger accountability, and aligned incentives across divisions, financial recovery will remain out of reach. An integrated, performance-oriented model offers the most realistic path to operational efficiency and long-term viability.

Reforming loss-making institutions like Sri Lankan Airlines is not merely a matter of leadership change — it is a structural overhaul essential to ensuring these entities contribute productively to the national economy rather than remain perpetual burdens.

By Chula Goonasekera – Citizen Analyst

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Features

Why Pi Day?

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International Day of Mathematics falls tomorrow

The approximate value of Pi (π) is 3.14 in mathematics. Therefore, the day 14 March is celebrated as the Pi Day. In 2019, UNESCO proclaimed 14 March as the International Day of Mathematics.

Ancient Babylonians and Egyptians figured out that the circumference of a circle is slightly more than three times its diameter. But they could not come up with an exact value for this ratio although they knew that it is a constant. This constant was later named as π which is a letter in the Greek alphabet.

Archimedes

It was the Greek mathematician Archimedes (250 BC) who was able to find an upper bound and a lower bound for this constant. He drew a circle of diameter one unit and drew hexagons inside and outside the circle such that the sides of each hexagon touch the sides of the circle. In mathematics the circle passing through all vertices of a polygon is called a ‘circumcircle’ and the largest circle that fits inside a polygon tangent to all its sides is called an ‘incircle’. The total length of the smaller hexagon then becomes the lower bound of π and the length of the hexagon outside the circle is the upper bound. He realised that by increasing the number of sides of the polygon can make the bounds get closer to the value of Pi and increased the number of sides to 12,24,48 and 60. He argued that by increasing the number of sides will ultimately result in obtaining the original circle, thereby laying the foundation for the theory of limits. He ended up with the lower bound as 22/7 and the upper bound 223/71. He could not continue his research as his hometown Syracuse was invaded by Romans and was killed by one of the soldiers. His last words were ‘do not disturb my circles’, perhaps a reference to his continuing efforts to find the value of π to a greater accuracy.

Archimedes can be considered as the father of geometry. His contributions revolutionised geometry and his methods anticipated integral calculus. He invented the pulley and the hydraulic screw for drawing water from a well. He also discovered the law of hydrostatics. He formulated the law of levers which states that a smaller weight placed farther from a pivot can balance a much heavier weight closer to it. He famously said “Give me a lever long enough and a place to stand and I will move the earth”.

Mathematicians have found many expressions for π as a sum of infinite series that converge to its value. One such famous series is the Leibniz Series found in 1674 by the German mathematician Gottfried Leibniz, which is given below.

π = 4 ( 1 – 1/3 + 1/5 – 1/7 + 1/9 – ………….)

The Indian mathematical genius Ramanujan came up with a magnificent formula in 1910. The short form of the formula is as follows.

π = 9801/(1103 √8)

For practical applications an approximation is sufficient. Even NASA uses only the approximation 3.141592653589793 for its interplanetary navigation calculations.

It is not just an interesting and curious number. It is used for calculations in navigation, encryption, space exploration, video game development and even in medicine. As π is fundamental to spherical geometry, it is at the heart of positioning systems in GPS navigations. It also contributes significantly to cybersecurity. As it is an irrational number it is an excellent foundation for generating randomness required in encryption and securing communications. In the medical field, it helps to calculate blood flow rates and pressure differentials. In diagnostic tools such as CT scans and MRI, pi is an important component in mathematical algorithms and signal processing techniques.

This elegant, never-ending number demonstrates how mathematics transforms into practical applications that shape our world. The possibilities of what it can do are infinite as the number itself. It has become a symbol of beauty and complexity in mathematics. “It matters little who first arrives at an idea, rather what is significant is how far that idea can go.” said Sophie Germain.

Mathematics fans are intrigued by this irrational number and attempt to calculate it as far as they can. In March 2022, Emma Haruka Iwao of Japan calculated it to 100 trillion decimal places in Google Cloud. It had taken 157 days. The Guinness World Record for reciting the number from memory is held by Rajveer Meena of India for 70000 decimal places over 10 hours.

Happy Pi Day!

The author is a senior examiner of the International Baccalaureate in the UK and an educational consultant at the Overseas School of Colombo.

by R N A de Silva

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Features

Sheer rise of Realpolitik making the world see the brink

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A combined US-Israel attack on Iran.(BBC)

The recent humanly costly torpedoing of an Iranian naval vessel in Sri Lanka’s Exclusive Economic Zone by a US submarine has raised a number of issues of great importance to international political discourse and law that call for elucidation. It is best that enlightened commentary is brought to bear in such discussions because at present misleading and uninformed speculation on questions arising from the incident are being aired by particularly jingoistic politicians of Sri Lanka’s South which could prove deleterious.

As matters stand, there seems to be no credible evidence that the Indian state was aware of the impending torpedoing of the Iranian vessel but these acerbic-tongued politicians of Sri Lanka’s South would have the local public believe that the tragedy was triggered with India’s connivance. Likewise, India is accused of ‘embroiling’ Sri Lanka in the incident on account of seemingly having prior knowledge of it and not warning Sri Lanka about the impending disaster.

It is plain that a process is once again afoot to raise anti-India hysteria in Sri Lanka. An obligation is cast on the Sri Lankan government to ensure that incendiary speculation of the above kind is defeated and India-Sri Lanka relations are prevented from being in any way harmed. Proactive measures are needed by the Sri Lankan government and well meaning quarters to ensure that public discourse in such matters have a factual and rational basis. ‘Knowledge gaps’ could prove hazardous.

Meanwhile, there could be no doubt that Sri Lanka’s sovereignty was violated by the US because the sinking of the Iranian vessel took place in Sri Lanka’s Exclusive Economic Zone. While there is no international decrying of the incident, and this is to be regretted, Sri Lanka’s helplessness and small player status would enable the US to ‘get away with it’.

Could anything be done by the international community to hold the US to account over the act of lawlessness in question? None is the answer at present. This is because in the current ‘Global Disorder’ major powers could commit the gravest international irregularities with impunity. As the threadbare cliché declares, ‘Might is Right’….. or so it seems.

Unfortunately, the UN could only merely verbally denounce any violations of International Law by the world’s foremost powers. It cannot use countervailing force against violators of the law, for example, on account of the divided nature of the UN Security Council, whose permanent members have shown incapability of seeing eye-to-eye on grave matters relating to International Law and order over the decades.

The foregoing considerations could force the conclusion on uncritical sections that Political Realism or Realpolitik has won out in the end. A basic premise of the school of thought known as Political Realism is that power or force wielded by states and international actors determine the shape, direction and substance of international relations. This school stands in marked contrast to political idealists who essentially proclaim that moral norms and values determine the nature of local and international politics.

While, British political scientist Thomas Hobbes, for instance, was a proponent of Political Realism, political idealism has its roots in the teachings of Socrates, Plato and latterly Friedrich Hegel of Germany, to name just few such notables.

On the face of it, therefore, there is no getting way from the conclusion that coercive force is the deciding factor in international politics. If this were not so, US President Donald Trump in collaboration with Israeli Rightist Premier Benjamin Natanyahu could not have wielded the ‘big stick’, so to speak, on Iran, killed its Supreme Head of State, terrorized the Iranian public and gone ‘scot-free’. That is, currently, the US’ impunity seems to be limitless.

Moreover, the evidence is that the Western bloc is reuniting in the face of Iran’s threats to stymie the flow of oil from West Asia to the rest of the world. The recent G7 summit witnessed a coming together of the foremost powers of the global North to ensure that the West does not suffer grave negative consequences from any future blocking of western oil supplies.

Meanwhile, Israel is having a ‘free run’ of the Middle East, so to speak, picking out perceived adversarial powers, such as Lebanon, and militarily neutralizing them; once again with impunity. On the other hand, Iran has been bringing under assault, with no questions asked, Gulf states that are seen as allying with the US and Israel. West Asia is facing a compounded crisis and International Law seems to be helplessly silent.

Wittingly or unwittingly, matters at the heart of International Law and peace are being obfuscated by some pro-Trump administration commentators meanwhile. For example, retired US Navy Captain Brent Sadler has cited Article 51 of the UN Charter, which provides for the right to self or collective self-defence of UN member states in the face of armed attacks, as justifying the US sinking of the Iranian vessel (See page 2 of The Island of March 10, 2026). But the Article makes it clear that such measures could be resorted to by UN members only ‘ if an armed attack occurs’ against them and under no other circumstances. But no such thing happened in the incident in question and the US acted under a sheer threat perception.

Clearly, the US has violated the Article through its action and has once again demonstrated its tendency to arbitrarily use military might. The general drift of Sadler’s thinking is that in the face of pressing national priorities, obligations of a state under International Law could be side-stepped. This is a sure recipe for international anarchy because in such a policy environment states could pursue their national interests, irrespective of their merits, disregarding in the process their obligations towards the international community.

Moreover, Article 51 repeatedly reiterates the authority of the UN Security Council and the obligation of those states that act in self-defence to report to the Council and be guided by it. Sadler, therefore, could be said to have cited the Article very selectively, whereas, right along member states’ commitments to the UNSC are stressed.

However, it is beyond doubt that international anarchy has strengthened its grip over the world. While the US set destabilizing precedents after the crumbling of the Cold War that paved the way for the current anarchic situation, Russia further aggravated these degenerative trends through its invasion of Ukraine. Stepping back from anarchy has thus emerged as the prime challenge for the world community.

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