Connect with us


Climate change: Looming threats to irrigated agriculture in SL



by Eng. Thushara Dissanayake

Sri Lanka boasts a legacy of massive ancient irrigation systems built by kings in the dry zone in ancient times. Parakramabhu the Great is believed to have said, “Let not even a drop of rain water go to the sea without benefiting man.” His words may have inspired the professionals in the water sector to develop the irrigated agriculture of the country further, harnessing high rainfall. Total annual renewable surface water resources in Sri Lanka is about 52 billion cubic meters (BCM), while total average annual rainfall is about 112 BCM.

Since the construction of the Senanayake Samudra in the 1950s as the largest reservoir in Sri Lanka, organizations in the water sector have completed many new reservoir projects of large capacities. Lunugamwehera, Weheragala, Deduru Oya, Kalugal Oya and Yan Oya are some of the recent achievements aimed at promoting irrigated agriculture.

The total storage capacity of major and medium irrigation reservoirs in Sri Lanka is about 3.4 BCM. In addition, major reservoirs constructed under the Accelerated Mahaweli Development Project are considered to be multipurpose as the main objective is the generation of hydro-electricity. Nevertheless, the contribution of the Mahaweli reservoirs to irrigated agriculture of the country is indispensable. With the newly constructed Moragahakanda-Kaluganga reservoirs, the total Mahaweli reservoir capacity stands at around 3.2 BCM. In addition, the total number of minor tanks in the country are estimated to be over 10,000, though the total water storage capacity is not accurately known.


Reliability of these reservoirs dependent on rainfall

Irrigated agriculture is the largest user of raw water in Sri Lanka. The country receives almost a constant volume of rainfall annually. But, this does not mean that we have no water issues. Generally, reservoir designs are based on past rainfall characteristics of the areas where they are located. Hence, they depend not only on annually expected rainfall volume but also the temporal pattern of rainfall. They will have the desired storage levels to cater to the demand only if they receive expected rainfall at the right time in the right quantity. In addition, it is important to ensure that the water withdrawal rates remain within the envisaged limits during the reservoir design. When rainfall becomes more variable within season and over time, reliability of reservoirs will decrease.


Climate change impacts reservoir operations

As explained above if a reservoir does not receive expected rainfall in right quantity in right time it will more or less fail to serve the water demand sites up to the expectation. On the contrary, if it gets rainfall more than expected during a operation cycle the additional amount of water may spill out of the reservoir and find its way to the the sea unless there are any other storage reservoirs downstream to receive it.

The climate change has caused rainfall to behave erratically. Technically speaking what we experience today is a temporal variation accompanied with fluctuation in intensities. Climate change experts predict that Sri Lanka will experience longer dry spells frequently in the future. During such dry spells, often unforeseen, our reservoirs would be incapable of supplying the irrigation water demands continuously throughout the cultivation season.

The global warming or the increase in atmospheric temperature is the root cause of climate change. Hence, the other major impact of climate change is an increase in evapotranspiration. As a consequence, water requirement of the agricultural crops goes up demanding more water from reservoirs. In the meantime, water losses from the reservoirs themselves by way of evaporation will also go up. These scenarios will create more water stresses on irrigated agriculture in future.

When the conditions are not favourable for agriculture there will be a sharp decrease in people engaged in agriculture abandoning their lands. Hence, this crisis should not be understood merely as a water crisis as it has the potential to have ramifications in other social and economic spheres. Therefore, the decrease in agricultural production will lead to higher selling prices, which neither the government nor the consumer is happy about.


Possible interventions to

resolve the issue

We are not in a position to control a natural phenomenon like rainfall nor to predict the pattern of climate change and its impacts in future accurately. Hence, only option available with us is improving our water management strategies and practices. The construction of storage reservoirs wherever possible will only be a part of the solution. However, we have utilized or identified almost all possible locations for reservoir construction by, now and most of the remaining places have high social and environmental implications.


Under these circumstances some alternatives that may be use to the stakeholders concerned are discussed below. It should be acknowledged that some of these concepts are already in practice but in an ad hoc manner. What is needed is to implement them with clear goals and monitor and assess the outcomes after implementation.


Irrigation system modernization

We are not in a position to control a natural phenomenon like rainfall. Besides, we are not able to predict the pattern of climate change and its impacts in the future accurately. Hence, only option available to us is improving our water management strategies and practices.

At present the actual water requirement for producing 1kg of paddy is around 2,500 – 3,500 litres while the crop requirement is about 1,400 litres. This higher requirement is mainly due to the water losses during conveyance and application. Our overall irrigation water use efficiencies are assumed to be just 40 per cent, though no adequate research has been done on this at the field level to calculate it accurately systemwise.

Currently, many countries are working on irrigation modernization (IM) to ensure sustainable irrigated agriculture. The Food and Agriculture Organization (FAO) defines IM as “a process of technical and managerial upgrading (as opposed to mere rehabilitation) of irrigation schemes combined with institutional reforms, with the objective to improve resource utilization (labour, water, economic, environmental) and water delivery service to farms”. Simply speaking, IM consists of a set of interventions to improve water management and level of on-farm services to farmers, which eventually leads to improved crop production and resilience to climate change under the present context. It includes both engineering and management interventions.

These interventions for better water management are mainly as follows:


1. Upgrading of water conveyance systems so that evaporation and infiltration losses can be minimised. Deficient canals are replaced with concrete lined canals and underground pipes

2. Process improvement in water allocation to farmers with modern techniques like supervisory control and data acquisition (SCADA), that intervenes in the process without changing the rules of the water management

3. Pragmatic desilting of reservoirs to regain their original capacities where applicable

4. Improvement of agricultural roads and access roads in farming areas to facilitate easy operations and management

5. Capacity building of farmers


Watershed conservation

All the irrigation systems are not reservoir-based. There are large number of anicut-based minor irrigation systems. They depend water diverted from rivers or streams. The success of these systems depends on the water availability of rivers and streams.

During rain, a considerable portion of water infiltrates into the ground, and rivers and streams are fed gradually by this groundwater making them perennial. For this mechanism, forests in the river basins play a major role by delaying rain water runoff, which in turn helps ground water recharge. Yet, the issue is diminishing forest cover in our watersheds. This rate of forest cover reduction will adversely affect ground water infiltration and eventually result in dried up rivers and streams. Further, agriculture depending on ground water will face water stresses. Hence, importance of watershed conservation goes without saying.


Farmers’ responsibilities and the role of the extension services

Sri Lankan farmers are supplied with irrigation water free. This does not mean that water does not involve any costs. Even though the relevant authorities could intervene to minimise conveyance water losses of the systems, the control of water application is mainly in farmers’ hands. Therefore, they also have a big role to play in minimising water application losses.

Traditional water application methods should be replaced with best water saving methods. The method known as alternative wetting and drying (AWD), introduced a long time ago, is a water management technique practised in paddy cultivation that need much less water than the usual practice of keeping standing water in the paddy field and proven to give higher yields. In areas where water stress is frequent crops that require less water should be grown with appropriate cultivation methods. If there is an evident shift in rainy season, crop cultivation periods can be adjusted to allow earlier or later planting so that both coincide, in order to reduce irrigation water use.

Where most of the farmers are concerned, dominant factor in the crop selection process seems to be market price and not giving enough attention to crop water requirements. In some cases, it is the farmers’ status quo that matters. Hence, relevant authorities should carefully focus on these issues when they render their extension services to the farmer community. In this respect, better inter-agency cooperation and communication and active participation are essential. No need to mention how the modern technology can be used by the authorities for creating an effective work environment.


Final remarks


The focus of this article has been on looming threats to our irrigated agriculture and discuss few proactive measures briefly and the increasing demand for food due to increasing population has not been factored in. Implementing aforesaid proactive measures need the dedicated action of many players including politicians, public sector organisations and the farmer community. Failure to take prompt action will result in additional stress in food production in the future and that in turn will affect the economy of the country as more and more food items will have to be imported.

(The writer is a chartered Civil Engineer. This article is based on his personal views and does not reflect those of the organisations where he holds positions.) 

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *


Islamophobia and the threat to democratic development



There’s an ill more dangerous and pervasive than the Coronavirus that’s currently sweeping Sri Lanka. That is the fear to express one’s convictions. Across the public sector of the country in particular many persons holding high office are stringently regulating and controlling the voices of their consciences and this bodes ill for all and the country.

The corrupting impact of fear was discussed in this column a couple of weeks ago when dealing with the military coup in Myanmar. It stands to the enduring credit of ousted Myanmarese Head of Government Aung San Suu Kyi that she, perhaps for the first time in the history of modern political thought, singled out fear, and not power, as the principal cause of corruption within the individual; powerful or otherwise.

To be sure, power corrupts but the corrupting impact of fear is graver and more devastating. For instance, the fear in a person holding ministerial office or in a senior public sector official, that he would lose position and power as a result of speaking out his convictions and sincere beliefs on matters of the first importance, would lead to a country’s ills going unaddressed and uncorrected.

Besides, the individual concerned would be devaluing himself in the eyes of all irrevocably and revealing himself to be a person who would be willing to compromise his moral integrity for petty worldly gain or a ‘mess of pottage’. This happens all the while in Lankan public life. Some of those who have wielded and are wielding immense power in Sri Lanka leave very much to be desired from these standards.

It could be said that fear has prevented Sri Lanka from growing in every vital respect over the decades and has earned for itself the notoriety of being a directionless country.

All these ills and more are contained in the current controversy in Sri Lanka over the disposal of the bodies of Covid victims, for example. The Sri Lankan polity has no choice but to abide by scientific advice on this question. Since authorities of the standing of even the WHO have declared that the burial of the bodies of those dying of Covid could not prove to be injurious to the wider public, the Sri Lankan health authorities could go ahead and sanction the burying of the bodies concerned. What’s preventing the local authorities from taking this course since they claim to be on the side of science? Who or what are they fearing? This is the issue that’s crying out to be probed and answered.

Considering the need for absolute truthfulness and honesty on the part of all relevant persons and quarters in matters such as these, the latter have no choice but to resign from their positions if they are prevented from following the dictates of their consciences. If they are firmly convinced that burials could bring no harm, they are obliged to take up the position that burials should be allowed.

If any ‘higher authority’ is preventing them from allowing burials, our ministers and officials are conscience-bound to renounce their positions in protest, rather than behave compromisingly and engage in ‘double think’ and ‘double talk’. By adopting the latter course they are helping none but keeping the country in a state of chronic uncertainty, which is a handy recipe for social instabiliy and division.

In the Sri Lankan context, the failure on the part of the quarters that matter to follow scientific advice on the burials question could result in the aggravation of Islamophobia, or hatred of the practitioners of Islam, in the country. Sri Lanka could do without this latter phobia and hatred on account of its implications for national stability and development. The 30 year war against separatist forces was all about the prevention by military means of ‘nation-breaking’. The disastrous results for Sri Lanka from this war are continuing to weigh it down and are part of the international offensive against Sri Lanka in the UNHCR.

However, Islamophobia is an almost world wide phenomenon. It was greatly strengthened during Donald Trump’s presidential tenure in the US. While in office Trump resorted to the divisive ruling strategy of quite a few populist authoritarian rulers of the South. Essentially, the manoeuvre is to divide and rule by pandering to the racial prejudices of majority communities.

It has happened continually in Sri Lanka. In the initial post-independence years and for several decades after, it was a case of some populist politicians of the South whipping-up anti-Tamil sentiments. Some Tamil politicians did likewise in respect of the majority community. No doubt, both such quarters have done Sri Lanka immeasurable harm. By failing to follow scientific advice on the burial question and by not doing what is right, Sri Lanka’s current authorities are opening themselves to the charge that they are pandering to religious extremists among the majority community.

The murderous, destructive course of action adopted by some extremist sections among Muslim communities world wide, including of course Sri Lanka, has not earned the condemnation it deserves from moderate Muslims who make-up the preponderant majority in the Muslim community. It is up to moderate opinion in the latter collectivity to come out more strongly and persuasively against religious extremists in their midst. It will prove to have a cementing and unifying impact among communities.

It is not sufficiently appreciated by governments in the global South in particular that by voicing for religious and racial unity and by working consistently towards it, they would be strengthening democratic development, which is an essential condition for a country’s growth in all senses.

A ‘divided house’ is doomed to fall; this is the lesson of history. ‘National security’ cannot be had without human security and peaceful living among communities is central to the latter. There cannot be any ‘double talk’ or ‘politically correct’ opinions on this question. Truth and falsehood are the only valid categories of thought and speech.

Those in authority everywhere claiming to be democratic need to adopt a scientific outlook on this issue as well. Studies conducted on plural societies in South Asia, for example, reveal that the promotion of friendly, cordial ties among communities invariably brings about healing among estranged groups and produces social peace. This is the truth that is waiting to be acted upon.

Continue Reading


Pakistan’s love of Sri Lanka



By Sanjeewa Jayaweera

It was on 3rd January 1972 that our family arrived in Karachi from Moscow. Our departure from Moscow had been delayed for a few weeks due to the military confrontation between Pakistan and India. It ended on 16th December 1971. After that, international flights were not permitted for some time.

The contrast between Moscow and Karachi was unbelievable. First and foremost, Moscow’s temperature was near minus 40 degrees centigrade, while in Karachi, it was sunny and a warm 28 degrees centigrade. However, what struck us most was the extreme warmth with which the airport authorities greeted our family. As my father was a diplomat, we were quickly ushered to the airport’s VIP Lounge. We were in transit on our way to Rawalpindi, the airport serving the capital of Islamabad.

We quickly realized that the word “we are from Sri Lanka” opened all doors just as saying “open sesame” gained entry to Aladdin’s cave! The broad smile, extreme courtesy, and genuine warmth we received from the Pakistani people were unbelievable.

This was all to do with Mrs Sirima Bandaranaike’s decision to allow Pakistani aircraft to land in Colombo to refuel on the way to Dhaka in East Pakistan during the military confrontation between Pakistan and India. It was a brave decision by Mrs Bandaranaike (Mrs B), and the successive governments and Sri Lanka people are still enjoying the fruits of it. Pakistan has been a steadfast and loyal supporter of our country. They have come to our assistance time and again in times of great need when many have turned their back on us. They have indeed been an “all-weather” friend of our country.

Getting back to 1972, I was an early beneficiary of Pakistani people’s love for Sri Lankans. I failed the entrance exam to gain entry to the only English medium school in Islamabad! However, when I met the Principal, along with my father, he said, “Sanjeewa, although you failed the entrance exam, I will this time make an exception as Sri Lankans are our dear friends.” After that, the joke around the family dinner table was that I owed my education in Pakistan to Mrs B!

At school, my brother and I were extended a warm welcome and always greeted “our good friends from Sri Lanka.” I felt when playing cricket for our college; our runs were cheered more loudly than of others.

One particular incident that I remember well was when the Embassy received a telex from the Foreign inistry. It requested that our High Commissioner seek an immediate meeting with the Prime Minister of Pakistan, Mr Zulifikar Ali Bhutto (ZB), and convey a message from Mrs B. The message requested that an urgent shipment of rice be dispatched to Sri Lanka as there would be an imminent rice shortage. As the Ambassador was not in the station, the responsibility devolved on my father.

It usually takes about a week or more to get an audience with the Prime Minister (PM) of a foreign country due to their busy schedule. However, given the urgency, my father spoke to the Foreign Ministry’s Permanent Sectary, who fortunately was our neighbour and sought an urgent appointment. My father received a call from the PM’s secretary around 10 P.M asking him to come over to the PM’s residence. My father met ZB around midnight. ZB was about to retire to bed and, as such, was in his pyjamas and gown enjoying a cigar! He had greeted my father and had asked, “Mr Jayaweera, what can we do for great friend Madam Bandaranaike?. My father conveyed the message from Colombo and quietly mentioned that there would be riots in the country if there is no rice!

ZB had immediately got the Food Commissioner of Pakistan on the line and said, “I want a shipload of rice to be in Colombo within the next 72 hours!” The Food Commissioner reverted within a few minutes, saying that nothing was available and the last export shipment had left the port only a few hours ago to another country. ZB had instructed to turn the ship around and send it to Colombo. This despite protests from the Food Commissioner about terms and conditions of the Letter of Credit prohibiting non-delivery. Sri Lanka got its delivery of rice!

The next was the visit of Mrs B to Pakistan. On arrival in Rawalpindi airport, she was given a hero’s welcome, which Pakistan had previously only offered to President Gaddafi of Libya, who financially backed Pakistan with his oil money. That day, I missed school and accompanied my parents to the airport. On our way, we witnessed thousands of people had gathered by the roadside to welcome Mrs B.

When we walked to the airport’s tarmac, thousands of people were standing in temporary stands waving Sri Lanka and Pakistan flags and chanting “Sri Lanka Pakistan Zindabad.” The noise emanating from the crowd was as loud and passionate as the cheering that the Pakistani cricket team received during a test match. It was electric!

I believe she was only the second head of state given the privilege of addressing both assemblies of Parliament. The other being Gaddafi. There was genuine affection from Mrs B amongst the people of Pakistan.

I always remember the indefatigable efforts of Mr Abdul Haffez Kardar, a cabinet minister and the President of the Pakistan Cricket Board. From around 1973 onwards, he passionately championed Sri Lanka’s cause to be admitted as a full member of the International Cricket Council (ICC) and granted test status. Every year, he would propose at the ICC’s annual meeting, but England and Australia’s veto kept us out until 1981.

I always felt that our Cricket Board made a mistake by not inviting Pakistan to play our inaugural test match. We should have appreciated Mr Kardar and Pakistan’s efforts. In 1974 the Pakistan board invited our team for a tour involving three test matches and a few first-class games. Most of those who played in our first test match was part of that tour, and no doubt gained significant exposure playing against a highly talented Pakistani team.

Several Pakistani greats were part of the Pakistan and India team that played a match soon after the Central Bank bomb in Colombo to prove that it was safe to play cricket in Colombo. It was a magnificent gesture by both Pakistan and India. Our greatest cricket triumph was in Pakistan when we won the World Cup in 1996. I am sure the players and those who watched the match on TV will remember the passionate support our team received that night from the Pakistani crowd. It was like playing at home!

I also recall reading about how the Pakistani government air freighted several Multi Barrell artillery guns and ammunition to Sri Lanka when the A rmy camp in Jaffna was under severe threat from the LTTE. This was even more important than the shipload of rice that ZB sent. This was crucial as most other countries refused to sell arms to our country during the war.

Time and again, Pakistan has steadfastly supported our country’s cause at the UNHCR. No doubt this year, too, their diplomats will work tirelessly to assist our country.

We extend a warm welcome to Mr Imran Khan, the Prime Minister of Pakistan. He is a truly inspirational individual who was undoubtedly an excellent cricketer. Since retirement from cricket, he has decided to get involved in politics, and after several years of patiently building up his support base, he won the last parliamentary elections. I hope that just as much as he galvanized Sri Lankan cricketers, his political journey would act as a catalyst for people like Kumar Sangakkara and Mahela Jayawardene to get involved in politics. Cricket has been called a “gentleman’s game.” Whilst politics is far from it!.

Continue Reading


Covid-19 health rules disregarded at entertainment venues?



Believe me, seeing certain videos, on social media, depicting action, on the dance floor, at some of these entertainment venues, got me wondering whether this Coronavirus pandemic is REAL!

To those having a good time, at these particular venues, and, I guess, the management, as well, what the world is experiencing now doesn’t seem to be their concerned.

Obviously, such irresponsible behaviour could create more problems for those who are battling to halt the spread of Covid-19, and the new viriant of Covid, in our part of the world.

The videos, on display, on social media, show certain venues, packed to capacity – with hardly anyone wearing a mask, and social distancing…only a dream..

How can one think of social distancing while gyrating, on a dance floor, that is over crowded!

If this trend continues, it wouldn’t be a surprise if Coronavirus makes its presence felt…at such venues.

And, then, what happens to the entertainment scene, and those involved in this field, especially the musicians? No work, whatsoever!

Lots of countries have closed nightclubs, and venues, where people gather, in order to curtail the spread of this deadly virus that has already claimed the lives of thousands.

Thailand did it and the country is still having lots of restrictions, where entertainment is concerned, and that is probably the reason why Thailand has been able to control the spread of the Coronavirus.

With a population of over 69 million, they have had (so far), a little over 25,000 cases, and 83 deaths, while we, with a population of around 21 million, have over 80,000 cases, and more than 450 deaths.

I’m not saying we should do away with entertainment – totally – but we need to follow a format, connected with the ‘new normal,’ where masks and social distancing are mandatory requirements at these venues. And, dancing, I believe, should be banned, at least temporarily, as one can’t maintain the required social distance, while on the dance floor, especially after drinks.

Police spokesman DIG Ajith Rohana keeps emphasising, on TV, radio, and in the newspapers, the need to adhere to the health regulations, now in force, and that those who fail to do so would be penalised.

He has also stated that plainclothes officers would move around to apprehend such offenders.

Perhaps, he should instruct his officers to pay surprise visits to some of these entertainment venues.

He would certainly have more than a bus load of offenders to be whisked off for PCR/Rapid Antigen tests!

I need to quote what Dr. H.T. Wickremasinghe said in his article, published in The Island of Tuesday, February 16th, 2021:

“…let me conclude, while emphasising the need to continue our general public health measures, such as wearing masks, social distancing, and avoiding crowded gatherings, to reduce the risk of contact with an infected person.

“There is no science to beat common sense.”

But…do some of our folks have this thing called COMMON SENSE!

Continue Reading