University of Jaffna, Srilanka
Civil Engineering
Devolution of power has been an alternative to the demand for separation by the Tamil speaking people in the North, East provinces of Sri Lanka. The Indo-Lanka Accord signed on 29 July 1987 required the Sri Lankan government to devolve... more
Devolution of power has been an alternative to the demand for separation by the Tamil speaking people in the North, East provinces of Sri Lanka. The Indo-Lanka Accord signed on 29 July 1987 required the Sri Lankan government to devolve powers to the provinces and, in the interim, to merge the Northern and Eastern provinces into one administrative unit. The accord required a referendum to be held by 31 December 1988 in the Eastern Province to decide whether the merger should be permanent. Crucially, the accord allowed the Sri Lankan president to postpone the referendum at his discretion. Unlike any other province, this matter is linked very closely with the political aspirations of the Tamil speaking people. This alternative was accepted by the Tamil speaking people on the guarantee given by the Government of India in late eighties. On 14 November 1987 the Sri Lankan Parliament passed the 13th Amendment to the 1978 Constitution of Sri Lanka and the Provincial Councils Act No 42 of 1987, establishing provincial councils. Nine provincial councils were created by order on 3 February. On September 2 and 8 1988 President Jayewardene issued proclamations enabling the Northern and Eastern provinces to be one administrative unit administered by one elected Council. The North-East Province was born. There are three lists dealing the power sharing mechanism. Author spells out the ways and means of strengthening the power sharing by changing the contents of these three lists based on his research during past couple of years and his experience in the field of development activity.
A study was carryout for a restricted ground water catchment about 160 sq. meters in Vavuniya in northern Sri Lanka to find out an operational policy of minor and medium Irrigation schemes, to recharge the ground water system to increase... more
A study was carryout for a restricted ground water catchment about 160 sq. meters in Vavuniya in northern Sri Lanka to find out an operational policy of minor and medium Irrigation schemes, to recharge the ground water system to increase the economic pumping. Forty one wells were identified as observation wells within the study area of 160 sq. meters to represent the aquifer. This study area was divided into forty one Thiession polygons by connecting the perpendicular bisectors of adjoining observation wells with four year seasonal collected (Oct.2000 - May.2004) water levels and three years seasonal historic (Oct.1997 - May.2000) water levels. A ground water simulation model was formulated for this polygonal network using integrated finite difference method in spreadsheet. The model was calibrated for the period from 1997 to 2001 having eight seasons. Since the initial values were taken as October 1997, the time step t was taken as 8 months followed by 4 months. These time steps were used alternatively throughout the calibration period from 1997 to 2001. The rainy season was taken from 1st October to 31st May of next year and non-rainy season was taken from 1st June to 30th September. By this calibration the hydrogeological stress parameters such as Transmissibility, Storage coefficient, Recharge coefficient for Irrigation scheme, Recharge coefficient for irrigation field, Recharge coefficient for rainfall and the Withdrawal factor for agro and domestic pumping were found using optimization technique. A complete water balance study for each polygon for each season was carried out. Forty one error models were prepared for the water balance, for each polygon for all the season. Each error model is a function of Transmissibility, Storage coefficient, Recharge coefficient for Irrigation scheme, Recharge coefficient for irrigation field, Recharge coefficient for rainfall and the Withdrawal factor for agro and domestic pumping. To avoid the negative & positive errors get cancelled, the squares of each seasonal error were added and minimized with suitable constrains. Practicable range for Transmissibility, Storage coefficient, Recharge coefficient for Irrigation scheme, Recharge coefficient for irrigation field, Recharge coefficient for rainfall and the Withdrawal factor for agro and domestic pumping were given during minimization as constrains. MATHCAD2000 was used for this optimization. Using the results obtained a validation of the model was carried out with three seasonal water level (Oct.2001 – May 2003). The model successfully predicted the water levels with very little error (less than three percent). Recalibration was done by slightly adjusting the stress parameters with all the eleven seasonal Oct. 1997 – May 2003) data. This integrated finite difference model in spreadsheet & calibrated by error optimization technique, validated and recalibrated was used to predict the system behavior for various operational policy of the Vavuniya restricted ground water catchment during this research. This article elaborates the use of electronic spread sheet and the use of optimization packages in this research work to formulate a ground water simulation model in any restricted catchment.
Within Jaffna peninsula there are three lagoons, Thondamanaru lagoon, Upparu lagoon and the Valukiaru lagoon with water spread area of 78, 26 and 14 squar killo meteres respectly. These three shallow lagoons cover around 11.8% of the... more
Within Jaffna peninsula there are three lagoons, Thondamanaru lagoon, Upparu lagoon and the Valukiaru lagoon with water spread area of 78, 26 and 14 squar killo meteres respectly. These three shallow lagoons cover around 11.8% of the penensola’s land area of 1036 square killo meter. These lagoons are having sea mouths at Thondamanaru, Ariyali and Arali in the vicinity of Indian Ocean which covers the penebsula by 160 km of coastline and no location of penensula is more than 10 km away from the coast. Hence it is very much susceptible to the salt water intrusion in to the land area. The water resource mainly the underground water in Jaffna Peninsula is totally polluted due to prolonged negligence and improper management of existing barrages at the logoon mouths and the salt water intrusion was taken place. In addition to these garbage and soakage pit pollution and increased usage of fertilizer chemicals also affected the quality of ground water. As a result, people are facing problem in getting good quality water in their wells. Due to the salt water intrusion, hundreds of acres of lands, hundreds of wells are in abandon stage. There is a positive relationship between the level of salt water intrusion in Jaffna peninsula and the operation of the gates of Thondamanaru, Ariyali and Arali barrages. There is strong evdince from a survey conducted recently that a good correlation can be found for the entire lagoon system operation with the level of salt water intrusion effect of Jaffna peninsula. This paper outlines the research methodology and its direction towards the problem accreditation of an on going research to address the problem and to find a solution to this long standing crucial issue of the people of Jaffna peninsula of Sri Lanka.
Heat on buildings mostly enters through roofs, as these are exposed to sun throughout the day. Many attempts have been made to reduce the ingress of heat by various methods like, by increasing thickness of roofs and providing insulation... more
Heat on buildings mostly enters through roofs, as these are exposed to sun throughout the day. Many attempts have been made to reduce the ingress of heat by various methods like, by increasing thickness of roofs and providing insulation by covering by reflectors, additional clay tile cover or lime-concrete cover or even reflector painting. Methods like continuous water spraying, intermittent spraying or ponding of water on roofs is either less effective or difficult to adopt. Similarly artificial or mechanical gadgets such as air-conditioners or desert coolers have high energy requirement. This paper is based on a continued research in finding economical, effective and natural way of cooling of dwelling units as well as multi storied buildings. Traditional methods like Khas Khas mats, water fountains, etc. were also analyzed along with the evaporative cooling. The feeling of comfort after taking bath as a result of utilization of body heat for the evaporation of water was also looked into. This lead to the efforts of creating comfortable living and working conditions in buildings by evaporation of water. A process was accordingly developed by this research utilizing the concept of cooling of buildings by roof surface evaporation. Finally this paper recommends some guidelines for Roof Surface Evaporation Cooling System for Sri Lankan climate condition.
Due to the man made blast, entire water stored in Kalmadu irrigation tank passed through the 125 m length and about 15m depth breach. This led the1397 ha of total irrigable area under gravity irrigation system was abundant for eight... more
Due to the man made blast, entire water stored in Kalmadu irrigation tank passed through the 125 m length and about 15m depth breach. This led the1397 ha of total irrigable area under gravity irrigation system was abundant for eight seasons. Species recorded of project area identified native, endemic plants 86% and 8% respectively. Fauna and flora found are common and the habitats are secondary in origin. Similar habitats were identified in surrounding, hence no possible threats to any important ecosystems. With the improvements in the dam and its operational efficiency, the overall impact is positive because it would result in a more favourable condition for the aquatic life in the reservoir and the river downstream and this scheme was functional until the year before the blast. EMP was monitored by the Environmental monitoring team at the field and mitigation measures were addressed by the contractor. More than 100,000m3 of earth (SC/GC material) collected from the tank bed was used for the construction for the closure of this breach. Resettled 4641 families with 18335 individuals were used for manual labour which was about 50-75 % of total labours used, to facilitate immediate employment for the IDPs from Kalmadu area with the purpose of uplifting livelihood and mental stability. After the completion of the work the paddy production is 8382 ton/year. Average per capita consumption of 108kg/individual results, 23.6% of the production is self sustain the Kalmadu area and the rest 76.4% is mixed with the national supply.
This article reveals that the different aspect of sustainable recovery process, where engineers should have played a different and profound professional roll in post tsunami development process. Unfortunately, our beloved country, which... more
This article reveals that the different aspect of sustainable recovery process, where engineers should have played a different and profound professional roll in post tsunami development process. Unfortunately, our beloved country, which all this time was spared by calamities of this magnitude, ultimately had to face the savage judgement of nature. The ravaging waves not only engulfed valuable lives of our very own but also brought down everything we had built in our coastal towns over the centuries in the blink of an eye the tsunami disaster has deeply affected the lives of the families living throughout the coastal belts of the country causing to be disrupted both by the damage to infrastructure and facilities for livelihood, as well as the disruption in the family structure and displacement of families. In addition to the negative impact, the tsunami has had on the livelihood support infrastructure in the 65% of the tsunami affected areas of Sri Lanka is also struggling to recover from three decades of civil war. The prolonged conflict, coupled with the impact of the tsunami has not only affected the livelihood support infrastructure, but the most of the other infrastructures as well. Hence the engineers are having the profound professional responsibilities to first to recover the damage caused by the natural disaster, then by rehabilitating/re-constructuring the damaged facilities. The final task to the engineers must be to support sustainable development activities to improve the socio economic status of the disaster affected community. The strategy spelled out in this article will be common for even post war recovery process also.
This research presents alternate policy decisions based on technical strategies to operate minor and medium irrigation schemes with integrated conjunctive use of surface and groundwater to improve groundwater systems in a restricted area... more
This research presents alternate policy decisions based on technical strategies to operate minor and medium irrigation schemes with integrated conjunctive use of surface and groundwater to improve groundwater systems in a restricted area for the economic pumping for agricultural and domestic water use, by optimizing the use of groundwater and surface water. Forty one domestic dug wells were identified as observation wells among the available domestic/agro wells within the study area of 185.23 km2, to represent the aquifer. This study area was divided into forty one Thiessen polygons. A complete water balance study for each polygon for each season was carried out. Water levels were predicted for changes in operational policy of minor and medium irrigation schemes by forgoing certain percentage of cultivation, boundary treatment to reduce the transmissibility in steps, and combination of both. The economic feasibility was analysed by taking the energy saved in pumping of raised groundwater as a benefit and boundary treatment cost and income loss due to change in operational policy of minor and medium irrigation schemes by forgoing certain percentage of cultivation as cost. The present worth of benefit and cost for various interest rate and project life period were calculated and compared. Change in operational policy of minor and medium irrigation schemes by forgoing one third of the cultivation under them or keeping one fourth of the storage of minor and medium irrigation schemes at any time together with 40% - 50% reduction in boundary permeability will recover an average of 60% to 70% of the loss of water table in any consecutive season in almost 95% of the area under consideration.
Unlike other natural resources, water is a unique resource, which renews itself. It is due to its constant circulation in the ocean-atmosphere-earth-ocean system. No matter how much water is consumed in daily life, its amount seldom... more
Unlike other natural resources, water is a unique resource, which renews itself. It is due to its constant circulation in the ocean-atmosphere-earth-ocean system. No matter how much water is consumed in daily life, its amount seldom dwindles. With time and under certain conditions water regains its properties and becomes fit for reuse. This is probably the reason why water resources appear to be unlimited for a long time. The North East region of Sri Lanka comprises the whole of eight districts, namely Jaffna, Mannar, Vavuniya, Kilinochchi, Mullaitivu, Trincomalee, Batticaloa, and Ampara and covers an area of 18,881sq.km. The population is around 3.17 million, with growth rate nearly 1.5% per annum. Agriculture, including fisheries, has been the principal economic activity in the province. Over 50% of the total work forces, in the region depend on irrigated agriculture for their livelihood. To accelerate the development and effective utilization of water resource identified within the region, a clearly defined policy formulation is essential. Only with a proper policy for the effective utilization and management of water resource, the expected result can be achieved
Jaffna is a peninsula which is 1000 km2 of land (out of which, Vadamarachchi Lagoon, Upparu Lagoon, Valukaiaru and Elephant pass Lagoon are covered with 75, 25, 15 and 100 km2 of surface area and 287, 212, 104 and 907 km2 of catchments... more
Jaffna is a peninsula which is 1000 km2 of land (out of which, Vadamarachchi Lagoon, Upparu Lagoon, Valukaiaru and Elephant pass Lagoon are covered with 75, 25, 15 and 100 km2 of surface area and 287, 212, 104 and 907 km2 of catchments area, respectively) covered by Indian Ocean by 160 km of coastline and no location is more than 10 km away from the coast. Hence it is very much susceptible to the salt water intrusion in to the land area. The water resource mainly the underground water in Jaffna Peninsula is totally polluted due to prolonged negligence and improper management of existing barrages at Thondamanaru, Ariyali and Ariyali and the salt water intrusion was taken place due to the none- maintenance of SWE bunds[16]. In addition to these garbage and soakage pit pollution and increased usage of fertilizer chemicals also affected the ground water. As a result, people are facing problem in getting good quality water in their wells. Due to the salt water intrusion, hundreds of acres of lands, hundreds of wells are in abandon stage[14].
A simplified reservoir simulation model was developed to study the water balance of the lagoon Downstream of the reservoirs of the four regulated river basins considered as local catchment to the Elephant Pass lagoon.Total inflow to the lake (lagoon) is the summation ofmonthly runoff yield from local catchment, direct rainfall on the lake and spill from upstream reservoirs.Outflow from the lake includes evaporation loss, percolation, demand and spillage.Evaporation loss from the lake was a function of water surface area and it was estimated from the monthly average Pan Evaporation values for the study area.Due to the absence of permeability measurements for the lagoon bed, monthly seepage loss wasassumed as 2.0% (0.05% for irrigation reservoirs)[14] of the volume of water stored in the lake.Monthly Rainfall data from the representative meteorological station and monthly spill volume from the upstream reservoirs were used as time series of input data. Low regulated water level (LRWL) was set at 0.0 m MSL with the proposed spill crest level of 1,2m MSL. Reservoir operation simulation wasdone with the constant release per month throughout the year. The results of the monthly simulation of lake showed that even after high evaporation loss, nearly 2MCM/month was available for release without upstream spill and 4MCM/monthwasavailable with upstream spill. Flushing out of lagoon bed in order to reduce the salinity can be carried out during the rainy season with excess water.It was found thatnearly 70% of the total inflow evaporates directly from the lake and it is an unproductive loss.Reservoir optimization is required to increase the productivity.This study can be basis for future detail hydrological model study and planning of Elephant Pass Lake for best use of water with minimum negative environmental impact.
A simplified reservoir simulation model was developed to study the water balance of the lagoon Downstream of the reservoirs of the four regulated river basins considered as local catchment to the Elephant Pass lagoon.Total inflow to the lake (lagoon) is the summation ofmonthly runoff yield from local catchment, direct rainfall on the lake and spill from upstream reservoirs.Outflow from the lake includes evaporation loss, percolation, demand and spillage.Evaporation loss from the lake was a function of water surface area and it was estimated from the monthly average Pan Evaporation values for the study area.Due to the absence of permeability measurements for the lagoon bed, monthly seepage loss wasassumed as 2.0% (0.05% for irrigation reservoirs)[14] of the volume of water stored in the lake.Monthly Rainfall data from the representative meteorological station and monthly spill volume from the upstream reservoirs were used as time series of input data. Low regulated water level (LRWL) was set at 0.0 m MSL with the proposed spill crest level of 1,2m MSL. Reservoir operation simulation wasdone with the constant release per month throughout the year. The results of the monthly simulation of lake showed that even after high evaporation loss, nearly 2MCM/month was available for release without upstream spill and 4MCM/monthwasavailable with upstream spill. Flushing out of lagoon bed in order to reduce the salinity can be carried out during the rainy season with excess water.It was found thatnearly 70% of the total inflow evaporates directly from the lake and it is an unproductive loss.Reservoir optimization is required to increase the productivity.This study can be basis for future detail hydrological model study and planning of Elephant Pass Lake for best use of water with minimum negative environmental impact.
— Valukaiaru is a wet weather drainage scheme in the Jaffna peninsula. It is situated in the middle part of the Valikamam division. Valukaiaru basin has a total area of 57 sq. km covering the District Secretariat (DS) divisions of... more
— Valukaiaru is a wet weather drainage scheme in the Jaffna peninsula. It is situated in the middle part of the Valikamam division. Valukaiaru basin has a total area of 57 sq. km covering the District Secretariat (DS) divisions of Tellipalai, Sandilipay, Chankanai and Uduvil. Valukaiaru scheme consists of a main drainage channel, eight tributary drainage channels and 65 minor tanks. The last control gate of this scheme, the Arali barrage is situated at the end of the channel at Arali. Valukaiaru starts from the village of Kurumpaciddy in Tellipalai DS Division and mixes with sea at the Arali barrage. Sea water intrusion through the damaged Arali barrage caused salinity problem in the soil and water resources of the Valukaiaru basin. Irrigation Department commenced the project on Rehabilitation of Arali barrage in 2008. By the renovation of Arali barrage sea water intrusion into the cultivable area through Valukaiaru has been stopped. Prevention of sea water intrusion significantly reduced the salinization of cultivatable lands and practicing effective water management will improve the productivity of the Agricultural Lands. The main causes that contribute to the low productivity of water and soil is improper management of water and agricultural practices, inadequate utilization of rainfall & sea water intrusion. More water is spilling without usage as there is not adequate capacity of tank although there is enough high and low lands for cultivation. This article analyses the problem and spell out a possible research solution to improve the water productivity of Valikamam.
— Groundwater is categorized as a common pool resource and is characterized by exclusion and substractbility. Given the nature of groundwater, user exclusion is an extremely difficult task. The cost of exclusion measures could outweigh... more
— Groundwater is categorized as a common pool resource and is characterized by exclusion and substractbility. Given the nature of groundwater, user exclusion is an extremely difficult task. The cost of exclusion measures could outweigh the benefits generated from the use of the resource. In a finite aquifer system, water withdrawal by one or more persons reduces the water available for others and thus groundwater becomes rival in use. Eventual depletion occurs when water withdrawals exceed replenishment rates over period of time. Groundwater suffers from appropriation and provision related problems. Short term gains often pushes users to over exploit the resource base with minimal or no maintenance. Absence of incentives, institutional structures, and social mechanisms would potentially lead to the destruction common pool resources. Farmer Organizations in Sri Lanka were formed to organize farmer activities at field level. They exist all over the country and formed at the Grama Niladari or Village level. Traditionally the Farmers's Organizations focused on providing membership to farmers, distribution of inputs, irrigation management at local level, and act as a body for collective voicing for farmers. Their involvement in groundwater management had been minimal in the past. Unlike Jaffna, existence of surface irrigation systems in other parts of the country could have contributed to the Farmer Organization's limited involvement in managing the groundwater resources. Given the nature of ground water use at individual level, difficulty of controlling their usage, the article examines potential role social capital could play in such circumstances. The article examines the potential role that the already existing Farmer Organizations could play in conserving and managing the scarce groundwater resources of Jaffna district. Ground water is the life line of Jaffna peninsula and the traditional shallow wells had been used for centuries for domestic and irrigation purposes. Approximately the 0.6 Million population of the district largely depends on groundwater sources for its various needs. The whole Jaffna peninsula is underlain by Miocene limestone formations which are generally 100 to 150 m thick, distinctly bedded, well jointed and highly karstified. Water mounds or lenses found within the limestone formation reach their peak during the monsoon rains of November –December. The aquifer boundary itself expands and contracts through the wet and dry seasons respectively. Various studies has placed the net groundwater recharge rate at an average 37% with Spatial variation of net groundwater recharge ranging from 12 to 69%, of annual rainfall.
—The proposal of converting Jaffna salt water lagoons in northern Sri Lanka to fresh water lakes is revived again in the recent days due to the increasing demand and dearth of fresh water in this region. Jaffna lagoon consists of two... more
—The proposal of converting Jaffna salt water lagoons in northern Sri Lanka to fresh water lakes is revived again in the recent days due to the increasing demand and dearth of fresh water in this region. Jaffna lagoon consists of two internal lagoons in the Jaffna peninsula and the external lagoon, Elephant pass. Four intermittent rivers with the total catchment area of 940km 2 drain to the Elephant pass lagoon. This study focused on water balance of the proposed Elephant Pass fresh water Lake and hence available productive water for usage. Microsoft Excel based simplified reservoir simulation model was developed to study the water balance of the lagoon. Minimum operating level was set at 0.0 m MSL with the proposed spill crest level of 1.2 m MSL. The results of the monthly simulation of lake showed that even after high evaporation loss, nearly 2 MCM/month was available for release throughout the year. With upstream spill, nearly 4 MCM/month was available and excess of 6 MCM/month could be drawn from December to April. This study can be basis for future detail hydrological model study and planning of Elephant Pass lagoon for best use of water with minimum negative environmental impact.
—Sri Lanka is an agriculture based developing country and currently Anuradhapura district provides the large contribution to the national economy through food production. The Mahakanadarawa irrigation scheme situated in east side of the... more
—Sri Lanka is an agriculture based developing country and currently Anuradhapura district provides the large contribution to the national economy through food production. The Mahakanadarawa irrigation scheme situated in east side of the A9 road, nearly 20km from the heart of the Anuradhapura city. This scheme has 126 Sqmls catchment and 36250 Ac ft. capacity. This scheme is the back born of the livelihood of around 5237 farmer families. The main income of these people is agriculture. Most of the farmers usually do paddy cultivation. Out of 6100 Acres the full extent cultivated in maha season and nearly 1500 acres cultivated in yala season. The cultivation of yala season reduces due to water shortage. The inflow of Mahakandarawa based on seasonal rain and inflow from Eruwewa .The Eruwewa Mahakandarawa feeder canal is not properly working due to poor maintenance and partially completed construction. This leads miss calculation on the estimation of the inflow from the Eruwewa clearly. The government and scholars identified some kidney disease spread areas far downstream of Mahakanadarawa scheme. Rambewa, Medawachchiya, Kebithigollawa etc. The major reason for this problem identified as the drinking water quality. The ground water of this area is highly polluted with the heavy material. Therefore the importance of the treated surface water become necessary. The government also announced to give the first priority to Drinking water. There is water shortage in Yala season in every year. The demand of drinking water makes another dimension to water sharing between the multiple users and emerging as bigger social problem. To address this problem a study incorporating, the agriculture pattern, and water balance of irrigation scheme and attitudes of people towards water management and reduce of the water wastage in this scheme is going on. This article spells out the importance, initial groundwork, the methodology of this curtail needy research study on socio engineering intervention of a social problem.
— Urbanization and migration of population towards cities become a new challenge nowadays in planning cities, particularly safe domestic water. One of the primary objective of sustainable development goal is to ensure the availability of... more
— Urbanization and migration of population towards cities become a new challenge nowadays in planning cities, particularly safe domestic water. One of the primary objective of sustainable development goal is to ensure the availability of good quality water for human consumption. Environmental engineers and scientists have the responsibility of monitoring the quality of sources for sustainable safe-water for human consumption. A major problem in northern Sri Lankan urban areas is the prolific occurrence of fecal coliforms in drinking water, obtained from dug-wells. The proximity of household septic-tanks and other related influences are attributed as the man causal factors of this crucial alarming thread. This article spells the results of an investigation conducted in Vavuniya Urban Council limits during 2009. The aim of this research is to assess the drinking water quality in Urban Council limits from an environmental management perspective, focused on identifying the relationships between well water quality and influence of the 'proximal influence of septic tanks'. It is found that more than 50% of the household dug-wells in the Vavuniya town are located well below the standard limit of 20 m distance from septic tanks. As such, a critical problem of coliform pollution is prevalent within the Vavuniya Urban Council limits. The research correlate this problem with alternate casual factors of urban water degradation and spells a management plan for the improvement of water supply for human consumption within this region Index Terms— water resource in Sri Lanka, urban water supply, dug-well water quality, coliform contamination. —————————— ——————————
— An assessment conducted in Vavuniya urban council limit from dug well water sample, the particular council consists nine Girama Niladhari Divisions. This study was assessed selected physio-chemical and biological parameters such as pH,... more
— An assessment conducted in Vavuniya urban council limit from dug well water sample, the particular council consists nine Girama Niladhari Divisions. This study was assessed selected physio-chemical and biological parameters such as pH, electric conductivity, total suspended solids, total hardness, fluoride, nitrate, nitrate nitrogen, iron, free chlorine and total coli form in 90 dug well water. Totally six Girama Niladhari Division zone water quality index is below 50. This means the water quality is good. Other four Girama Niladhari Division zones water quality index are 92, 64, 63 and 58 respectively. This indicates the water quality is poor. The major reason for lowering water quality is the presence of fecal coli form, which is exceeded its allowable level. Index Terms—water resource in Sri Lanka, urban water supply, dug-well water quality, coliform contamination, water quality index —————————— ——————————
Iranaimadu tank is the only major irrigation scheme in the northern Sri Lanka. The major portion of the agricultural sector in northern districts depend on the Iranaimadu tank for their agricultural activities specially paddy cultivation.... more
Iranaimadu tank is the only major irrigation scheme in the northern Sri Lanka. The major portion of the agricultural sector in
northern districts depend on the Iranaimadu tank for their agricultural activities specially paddy cultivation. The water shortage in yala
season of the Iranamadu tank, the primary source of water for the northern districts, signaled an imminent crisis to farmers, who are now
grappling with an uncertainty. Therefore the “Pedma” cultivation was introduced with the limited irrigation water supply through the D4 canal
in Maruthanagar Kilinochchi especially for the seed paddy production. The objective of this study was is to assess the suitability for
selection of Maruthanagar D4 canal for the “Pedma” cultivation. The analysis of the water conveyance efficiency, water quality parameters
and social impact analysis were done. The water conveyance efficiency was measured for different five flow rate at D4 canal. Electrical
conductivity, pH, total dissolve solids were measured at site for ten days with morning and afternoon temperature difference within a day.
Water conveyance efficiencies of D4 canal were always below the recommended level for all different flow rates and the values were
ranging from 52.9% to 68.9%. The D4 canal water had the acceptable value in relation to the irrigation water quality parameters as pH, EC,
TDS and salinity. Since the efficiency is lower than the recommended value, there is a need for construction and renovation of irrigation
structures for optimize the efficiency in D4 canal. Income levels of the farmers under the “Pedma” cultivation were far below than the
previous income levels. Inefficient land allocation and optimization and reduction in the household economy lead them to seek for an
efficient alternative, after a full scale rehabilitation and reconstruction of the irrigation infrastructure and to practice good water
management.
northern districts depend on the Iranaimadu tank for their agricultural activities specially paddy cultivation. The water shortage in yala
season of the Iranamadu tank, the primary source of water for the northern districts, signaled an imminent crisis to farmers, who are now
grappling with an uncertainty. Therefore the “Pedma” cultivation was introduced with the limited irrigation water supply through the D4 canal
in Maruthanagar Kilinochchi especially for the seed paddy production. The objective of this study was is to assess the suitability for
selection of Maruthanagar D4 canal for the “Pedma” cultivation. The analysis of the water conveyance efficiency, water quality parameters
and social impact analysis were done. The water conveyance efficiency was measured for different five flow rate at D4 canal. Electrical
conductivity, pH, total dissolve solids were measured at site for ten days with morning and afternoon temperature difference within a day.
Water conveyance efficiencies of D4 canal were always below the recommended level for all different flow rates and the values were
ranging from 52.9% to 68.9%. The D4 canal water had the acceptable value in relation to the irrigation water quality parameters as pH, EC,
TDS and salinity. Since the efficiency is lower than the recommended value, there is a need for construction and renovation of irrigation
structures for optimize the efficiency in D4 canal. Income levels of the farmers under the “Pedma” cultivation were far below than the
previous income levels. Inefficient land allocation and optimization and reduction in the household economy lead them to seek for an
efficient alternative, after a full scale rehabilitation and reconstruction of the irrigation infrastructure and to practice good water
management.
— Problems of drinking water in the Jaffna is an upcoming problem which mostly depended with increasing the population, growing the cultivation activities, opening the sewage in uncontrollable manner and etc. People of the Jaffna area... more
— Problems of drinking water in the Jaffna is an upcoming problem which mostly depended with increasing the population, growing the cultivation activities, opening the sewage in uncontrollable manner and etc. People of the Jaffna area depend on the ground water for all the activities using open well or tube-well. For all activities, the people extract water from underground, induced the badly behaved of quality of water fluctuating the years and also which case usually not related to one, this related with all people in the Jaffna area. The knowledge area covers the potential effects of the ground water in the Jaffna area and improve the problems and effort to bargain the solution for approaching problems using the collected knowledge and information from four of the previous work done by others are reviewed in this articles. The following five articles are mainly reviewed with other literatures referred. "Groundwater potential in the Jaffna Peninsula and impacts of climate change", "River for Jaffna-cultivating productive water from salt water Lagoons in Northern Srilanka-What the water balance of Elephant Pass lagoon demonstrates", "Water problems in the Jaffna peninsula", "Jaffna peninsula water resources challenges" and," assessment of groundwater resources in Jaffna limestone aquifer " .
— The Jaffna Peninsula lie in the northern-most part of Sri Lanka. It is separated from the mainland by two external lagoons. The Jaffna Peninsula depends for its water on the rainfall which percolates and stored in lime stone aquifers.... more
— The Jaffna Peninsula lie in the northern-most part of Sri Lanka. It is separated from the mainland by two external lagoons. The Jaffna Peninsula depends for its water on the rainfall which percolates and stored in lime stone aquifers. The average annual rainfall is 1284 mm/year and the potential vapour transpiration is 1858.8 mm. The Jaffna Peninsula is struggling to meet the water demand and quality of available ground water also threatened by pollutants. The major aquifers within Jaffna Peninsula located in Valikamam, Vadamaradchchi and Thenmaradchchi area. From 1966 several surveys and investigations were carried out to find out the water usage pattern, required water and available water, etc. The studies which are carried out in different periods on deriving possible " Safe Yield " from the aquifers of Jaffna Peninsula are showing inconsistent results for the same aquifers. In last few decades the ground water is exposed for the pollution due to over extraction for irrigation lead for sea water intrusion, heavy usage of agro chemicals lead to increase the Nitrate concentration beyond the limit and discharging industrial waste in to ground lead to the contamination of petroleum components.The studies done so far on estimating the availability of groundwater in Jaffna Peninsula have been carried out to certain extent and derived recommendations for " Safe Yield " as well. But the findings are varying with the time period for a specific aquifer. Also the carrying capacity of the aquifers are not clearly studied in detail as the groundwater in Jaffna Peninsula is stored in fractured weak limestone aquifers. Therefore the over storage of groundwater in the aquifers beyond their capacity may cause adverse impact to the environment.Based on the past studies, the recommended total " Safe Yield " from the aquifers in Jaffna Peninsula is 13,100 m 3 per day in dry season and 34,600 m 3 per day in wet season while having a basic water requirement for domestic need of 31,500 m 3 per day. Further available annual water resources is 718 m 3 per day per person which is less than the recommended amount in the World Water Development Report of the United Nations. These are indicating that the Jaffna Peninsula is facing the water scarcity.The availability of groundwater and the possible additional recharge shall be studied with correlation to the carrying capacity of the aquifer to ensure and improve the available water resources in a sustainable manner. This paper is analysed and summarised the past studies on groundwater in Jaffna Peninsula.
Harmonics "Harmonics" are all of those Sinewaves of different frequencies that make up a complex waveform, such as Triangle, Square, and all others. Nearly all signals contain energy at harmonic frequencies, in addition to the energy at... more
Harmonics "Harmonics" are all of those Sinewaves of different frequencies that make up a complex waveform, such as Triangle, Square, and all others. Nearly all signals contain energy at harmonic frequencies, in addition to the energy at the fundamental frequency. If all the energy in a signal is contained at the fundamental frequency, then that signal is a perfect sine wave. Some waveforms contain large amounts of energy at harmonic frequencies. Examples are square waves, sawtooth waves, and triangular waves.
- by Shajeef Piranath
- •