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Item Demographical characterization of dengue infected patients in Akurana medial officer of health area(central Province of Sri Lanka, University of Sri Jayawardnapura, Sri Lanka., 2015) Udayanga, N.W.B.A.L.; Gunathilaka, P.A.D.H.N.; Iqbal, M.C.M.; Kusumawathie, P.H.D.; Najim, M.M.M.; Amarasingha, U.S.; Abeyewickreme, W.Dengue has been recognized to be one of the major threats on the public health of many tropical countries including Sri Lanka. Controlling of the high rate of mortality caused by dengue, which remains without being altered regardless of the immense efforts and control strategies of the relevant authorities, has remained as a major challenge for the Sri Lankan health sector. Vulnerability assessment of communities to dengue infection is of higher importance in drafting and implementation of management plans to ensure effective management and controlling of dengue epidemics at the regional scale. Therefore, a statistic based analysis of the dengue patient characteristics was carried out to determine the susceptibility of population to dengue infection in Akurana Medical Officer of Health (MOH) area. Monthly records of reported dengue cases from 2010 to 2014 of the Akurana MOH division were collected. Normal Chi square test coupled with Paired-Chi square test was devised to investigate the impact of sex and age on the infection. MINITAB (version 14.12.0) software package was used for statistical analysis. In accordance with the results of the normal Chi square test, the Percentage Infected Male: Female Ratio (PIMFR) remains significantly altered throughout the period of study (p=0.001 61 (1.84%). However, according to the Paired-Chi square test, the vulnerability of age groups tend to shift significantly throughout the study period [>Χ2 (7, 0.95) = 14.067]. In conclusion males tend to indicate relatively high susceptibility to dengue. Age groups of 6 - 10, 11 - 20 and 21 - 30 could be recognized as highly vulnerable age groups in the community for dengue, while age group of >61 emerge as the least vulnerable age group for the infection of dengue in the Akurana MOH.Item Potential to Increase the Area under Paddy Cultivation with Domestic and Municipal Wastewater Irrigation in Kurunegala District(2010) Udagedara, U.S.C.; Najim, M.M.M.Use of domestic wastewater for agriculture was a traditional practice in Sri Lanka where leafy vegetables and medicinal plants were cultivated in backyards. The use of domestic and municipal wastewater could be an environmentally sound means of wastewater disposal and could reduce environmental pollution if utilized for paddy irrigation. This practice could also help to increase the economic productivity of the water and land. Therefore a study was conducted in selected Divisional Secretariat Divisions in Kurunegala District in order to explore the potential for land to be brought under paddy cultivation with the utilization of municipal and domestic wastewater. The quantity of wastewater generated was estimated based on the population and water consumption data. Data on the extent of paddy land under minor irrigation and rain-fed agriculture, potential cultivable land extent (known as asweddumized area), land area cultivated in maha (wet) and yala (dry) seasons, and the areas harvested were collected from the District Agriculture Department. It is noted that not all the available lands were cultivated and harvested in both the maha and yala seasons. The area of land that is not used for any crop production is higher in the yala season than in the maha season. In addition, only a part of the land area is harvested from the total area sown. Major reasons for crop failure are inadequate rainfall and shortage of supplementary irrigation water. The difference between the cultivable(asweddumized) extent and harvested extent shows the land that can potentially be brought under irrigation using municipal and domestic wastewater. The amount of land that can be so irrigated is much higher closer to the city where the storm water and other forms of wastewater are drained through common canal systems. Depending on the quantity and quality, and the availability of fresh irrigation water, municipal wastewater can be either diluted with irrigation water to meet the total irrigation water requirement, or can be used without any dilution. In addition to the increment of the land area under cultivation, there is a possibility of increasing the cropping intensity.Item Urban growth and wastewater agriculture: A study from Sri Lanka(2006) Najim, M.M.M.; Abayawardana, S.A.K.; Raschid-Sally, L.; Jayakody, P.Rapid urbanization and increasing water consumption accelerate wastewater generation in cities in less developed regions. This has resulted in an intensification of the water pollution problem, which is now no longer, simply an issue for environmentalists to deal with, but which irrigation engineers are being called upon to tackle. Three cities in Sri Lanka were used to demonstrate the global situation. Data was collected using open-ended questionnaires covering a variety of issues associated with urbanization. Results show that the simple application of wastewater on surrounding agricultural lands has the potential to increase the cropping intensity. Out of three cities, Kurunegala paddy farmers use diluted wastewater for their irrigation. Better nutrient management in the field will help farmers to optimize fertilizer application. Health risk is the main negative force for wastewater agriculture. With risk reduction measures, wastewater recycling in agriculture becomes a potentially viable solution to waste disposalItem LPWM Expert: An expert system for water management during land preparation in a paddy estate in Malaysia(Tropical Agricultural Research, 2004) Najim, M.M.M.; Haque, M.A.; Lee, T.S.Seberang Perak paddy estate, Malaysia, which practices intensive mechanized farming still uses the traditional approach in decision-making. Land preparation water management, the critical process to be completed within scheduled duration, needs better and quick management decisions for many alternative scenarios. A method proposed to encapsulate specific knowledge available with domain experts and generated through modeling to an expert system (LPWM Expert) is outlined. The LPWM expert consists a database, a modal base, a knowledge base and a user interface. Knowledge was gathered through discussions and interviews with domain experts. Collected quantitative data were used in modeling canal flows and water balance to extract knowledge for different possible scenarios. Knowledge base represent extracted knowledge as rules. All the rules in IF-THEN structure and syntax are verified with the help of wxCLIPS debugging capability and results generated by the LPWM expert are validated with the domain experts. The expert system proposes decisions for many combinations of scenarios considering all the possible variations in rain, irrigation water supply, secondary blocks, sub-estates, cropping seasons and cropping intensity. The LPWM expert is user friendly and efficient where the outputs are supported with graphics.Item Modeling Irrigation Water Delivery Schedule for Rice Cultivation in East Coast Malaysia(Tropical Agricultural Research, 2004) Najim, M.M.M.; Haque, M.A.; Lee, T.S.An irrigation water delivery-scheduling model has been developed to increase irrigation efficiency for a large-scale rice irrigation project in Malaysia. The study focused on modeling irrigation water delivery schedules during the main season and off-season of the rice-based project. The procedure used a water balance approach in which rainfall was considered as a stochastic variable. Rainfall and evapotranspiration values were used to estimate weekly irrigation water deliveries through the water balance equation. Comparison of the observed and computed irrigation delivery values for the main season and off-season showed that the observed values were higher than the computed values, indicating excess water supply in the field. With the application of this model, it was observed that a modification of the existing irrigation water delivery schedules would save a considerable amount of irrigation water during the main season and off-season. The computed irrigation schedules could save 19% and 11% of irrigation water in the main season and off-season respectively when compared with the traditional irrigation schedules.Item Scheduling the cropping calendar in wet-seeded rice schemes in Malaysia(Agricultural Water Management, 2005) Najim, M.M.M.; Haque, M.A.; Lee, T.S.The Besut Irrigation Scheme, Terengganu, Malaysia is one of the eight gazetted main rice-growing areas in Malaysia. These eight granaries are targeted to produce only 65% of the total rice requirements of the nation. This scheme faces water scarcity especially during the off-season with the present existing cropping schedule. This study discusses the ways and means to overcome the water scarcity problem by setting the calendar for cropping schedules taking into consideration rainfall, river flow available and irrigation water requirements. A water balance approach using 48 years of rainfall and weather data was pursued in this study. The present main season from land preparation to crop harvest lasts from 1st November to 6th April, with land preparation being carried out during the heaviest rains in early November. However, the heavier rains may result in the postponement of seeding. Delays in crop planting during this main season can result in the cancellation of the following off-season crop from May to October. Shifting the land preparation works from November 1 to an earlier date, September 15, would result in a better match of crop water needs with the prevailing rainfall season (normally most of the rainfall occurs between September and December). This proposed schedule (15th September?10th February) also increases the probability that land preparation and subsequent seeding can be done for a second crop in the revised off-season period, 15th March?10th August. The present off-season schedule is from 5th May to 7th October and water scarcity during the vegetative and reproductive phases of the crop growth can be a problem. With the shifting of the off-season to start on March 15, severe water shortage can be avoided. The proposed revised cropping schedules could reduce the irrigation water requirements for the main season and off-season by 30% (equivalent to 60 mm of water) and 19% (equivalent to 37 mm of water), respectively.Item Assessment of Agricultural NonPoint Source Model for a Watershed in Tropical Environment(Journal of Environmental Engineering, 2004) Najim, M.M.M.; Babel, M.S.; Loof, R.Very little work on the application of watershed modeling has been done in the tropical climatic conditions of Thailand to explore the nature of environmental problems arising from nonpoint source pollution due to agricultural activities, and to evaluate possible remedial measures and strategies. The present study attempts to verify the suitability of a nonpoint source pollution model, the Agricultural NonPoint Source model, for the Huai Nong Prong watershed in Southeastern Thailand. Extensive fieldwork was carried out to collect data and information needed for the model preparation and application. The study has revealed that simulated runoff volume, sediment, and nutrient yield from the watershed with mixed land use and relatively high slopes match favorably with observed data. For the ten rainfall events simulated, the coefficient of performance, a measure of model efficiency (equal to zero for a perfect match), was 0.09, 0.47, 0.09, and 0.03 for runoff volume, sediment yield, total nitrogen, and total phosphorus, respectively. The model, however, could not accurately simulate peak flow rates, suggesting the need for changes in the modeling approach or governing equations and relationships to calculate peak discharges in a tropical environment.Item Modeling water resources allocation in a run-of-the-river rice irrigation scheme(Water Resources Management, 2005) Najim, M.M.M.; Haque, M.A.; Lee, T.S.Seventy-five percent of the available water resources in Malaysia are used for rice irrigation. Proper water management must be given due emphasis to effectively manage the water resources. This study analyzed field level practices, which could save irrigation water and thus increase area to be irrigated. The analyses were conducted for both the pre-saturation and normal supply periods using field data collected at the Besut irrigation scheme, Malaysia. Based on field water requirements and available flows at the intake structures, canal simulation was performed using the CanalMan model (Utah State University) together with water balance. The results have shown that pre-saturation should not be done continuously unless flow rates are at least 9.00 and 3.00 m3 s?1 for the Besut and Angga barrages, respectively. If the flow rate falls below these values, then pre-saturation should be done in two phases. However, when the flow rate is between 5.00 and 5.50 m3 s?1 at Besut barrage, pre-saturation should be done in three phases. The simulated schedules were compared with present pre-saturation schedules and it was observed that irrigable area could be increased by 10% than that at present. During the period of normal irrigation supply to the fields, there must be flow rates of at least 5.00 m3 s?1 and 1.50 m3 s?1 at the Besut and Angga barrages, respectively; in order to maintain irrigation supply to the whole irrigation scheme. Otherwise, selective irrigation or irrigation on a rotational basis will have to be enforced.Item Modelling of Changes in Evapotranspiration for an Area in Peninsular Malaysia(Pertanika Journal of Science and Technology, 2005) Najim, M.M.M.; Lee, T.S.; Haque, M.A.; Feng, H.Y.A study was carried out to check the sensitivity of evapotranspiration estimation due to changes in climate. The study used 30 years of data from the meteorological station in the FELCRA paddy estate, Seberang Perak, Peninsular Malaysia. The effect of changes in the climatic variables, temperature, solar radiation, relative humidity and wind speed on evapotranspiration were analyzed. Results showed that the mean temperature, mean relative humidity, mean wind speed, and net global radiation have changed by + 0.182 oC, -0.73%, -0.0365 mis, and +0.146 MJ/m2 respectively per decade, while the short wave radiation received has decreased by 0.0037 MJ/m2 per decade. The statistical analysis of the evapotranspiration estimations using selected methods showed that the Penman-Monteith, Blaney-Criddle and Pan evaporation methods give similar estimations (P = 0.05) and are suitable for the study area. When changes to the present climate are imposed for future decades, the over-estimation rate is linear with the Blaney-Criddle and Penman methods whereas for the PenmanMonteith method it is exponential. The overall increment expected after 5 decades is 5.3% and 6.9% with Penman and Blaney-Criddle methods respectively. The Penman-Monteith shows a 74.4% increment in the evapotranspiration over the next five decades.Item In-time Rice Irrigation Water Management Under Limited Water Supply(Pertanika Journal of Science and Technology, 2005) Najim, M.M.M.; Haque, M.A.; Lee, T.S.In-time water distribution of canal water to the farmers has been a majorconcern of managers, planners and researchers involved in irrigation. This study analyzed the ways for water distribution and timely water release in a rice growing area during the pre-saturation period and the normal irrigation supply periods. The analyses were carried out using field data collected at the Besut Irrigation Scheme located in the northeastern corner of Peninsular Malaysia in the state of Terengganu. The scheme comprises two sub-schemes, giving a total irrigation area of 5, 164 ha for the overall Besut Irrigation Scheme. Based on field water requirements and available flows at the intake gates, canal simulations were performed and results show that land preparation should not be done continuously unless flow rates are at least 9.00 m3/s and 3.00 m3/s at the Besut Barrage and Angga Barrage respectively. If the respective flow rates fall below these values, then land preparation should be done in two phases. However, when the flow rate is between 5.00 and 5.50 m3/s at the Besut Barrage, land preparation is recommended to be carried out over three phases. During the normal irrigation supply period, flow rates of 6.00 m3/s and 1.75 m3/s for the Besut and Angga Barrage respectively, are to be maintained for the entire irrigation scheme, otherwise selective irrigation or irrigation on a rotational basis has to be enforced. When flow rates are 7.20 - 9.00 m3/s and 1.70 - 3.00 m3/s at the Besut and Angga Barrage respectively, then water should be released two days before the beginning of the pre-saturation period for the filling main and secondary canals. However, water should be released three days before the beginning of the pre-saturation period when flow rates are between 5.00 and 7.00 m3Is at the Besut Barrage. But irrigation water should release 5.00 hours before beginning the normal supply period in order to maintain the in-time irrigation schedule