http://ir.lib.ruh.ac.lk/handle/iruor/12355 Fri, 03 Apr 2026 23:53:03 GMT 2026-04-03T23:53:03Z http://ir.lib.ruh.ac.lk/handle/iruor/12837 Cover page Thu, 23 Oct 2008 00:00:00 GMT http://ir.lib.ruh.ac.lk/handle/iruor/12837 2008-10-23T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/12835 Table of Contents Thu, 23 Oct 2008 00:00:00 GMT http://ir.lib.ruh.ac.lk/handle/iruor/12835 2008-10-23T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/12827 Mapping the status of paddy Production system using GIS technique for developing the decision support systems in Kamburupitiya Divisional Secretariat Division Kahandage, P.D.; Rupasinghe, C.R.; Chandama, P.M. The demand of rice will increase at 1.1 % per year in Sri Lanka and the rice production should grow at the rate of 2.9% per year to fulfill this demand. GIS (Geographic Information System) has been known as a powerful tool to understand spatial data analysis and this tool is recently applied to agricultural sector as well. This technique can be applied to paddy sector also in order to increase the paddy production through proper information management. An extensive field survey was conducted to collect soil samples throughout the Kamburupitiya Divisional Secretariat Division. Soil samples were collected from 77 sampling sites at a depth of 5-20 cm and GPS locations were recorded. Machinery information related to Paddy production was collected using questionnaire survey. Information related to yield was collected from the Agrarian Services centers. pH values of Soil samples were measured using a pH meter. Soil Organic Carbon and Nitrogen were analyzed using Walkley and Black rapid titration method and Kjeldhal method respectively. Distribution map of pH and organic carbon were prepared by applying interpolating methods in GIS. ArcView GIS software was used for the spatial analysis and mapping. Results of the study revealed that Soil Organic Carbon percentage ranged from 0.27 %to 3.64%. Soil pH ranged from 3.06 to 7.3. Soil Nitrogen content was very low and it ranged from 0.021% to 0.235%. The Land Area with Suitable pH and Organic Carbon for paddy crop were estimated as 3936.9 ha and 791.9 ha respectively. Four major groups of varieties were found and many of those were limited to some GN divisions. Yield per unit area varied from 1111.3 to 4769kg/ha/year. Paddy Lands are cultivated under the Major Irrigation, Minor Irrigation and Rain fall. Major Irrigations are limited to the middle part of the DS Division. Minor Irrigations are limited to the Western part of the DS Division. Flood effected Paddy lands are found in the Western Part. Two wheel Tractors, Four wheel Tractors, Threshers, Harvesters, Sprayers and Rice Mills arc the mainly used machineries. Considerable numbers of above machineries are present but the distribution is poor. Thu, 23 Oct 2008 00:00:00 GMT http://ir.lib.ruh.ac.lk/handle/iruor/12827 2008-10-23T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/12826 A software application for calculating the groundwater level Wijewardane, D.S.R.; Navarathne, C.M.; Piyadasa, R.U.K.; Adikaram, K.K.L.B. Groundwater is the most cost effective source of fresh water supply for domestic use and for irrigation. It is exploited through the construction of open dug wells or boreholes depending on the depth at which it occurs. It is observed that the quality of groundwater is drastically decreasing due to over exploitation of groundwater from wells, urbanization and land use changes etc.Poor quality groundwater and lowering of the groundwater table have disastrous consequences like making the groundwater unfit to drink and for other domestic uses, not suitable for irrigation means failure of crops. Therefore, it is important to improve the quality of groundwater and assess the safe yield that can be extracted from an aquifer to prevent a significant drop of the groundwater level and thereby prevent the development of any of the above situation. In this regard, quantification of the rate of natural groundwater recharge is a pre requisite for efficient groundwater resource management. The main objective of this research is to develop a software model to estimate the height of recharge and the present level of groundwater table capable of data storage and data displaying ability either by graphically or through reports. Using this model, groundwater recharge is calculated either by an equation that is specified by the user or the equation in-built within the model. Groundwater balance Equation is used as the in-built equation for the new system. According to the equation provided, all parameter were calculated by the model or the user may use own values as he wishes. All the results are stored in the system for further analysis and those data are obtained in a report form. After commencing the study, the monthly rainfall values at the end of first, second and third months were 120 mm, 247.85 mm, and 219 mm respectively. The average output from the well was 60 mm per month. When the date of the study was commenced, the initial depth to the groundwater table was 183 cm from the surface. At the end of the first, second and third months, the values were recorded as 182 cm, 180 cm and 181cm respectively. The depth to the ground water table estimated using the developed software model for the first, second and third months were 195.78 cm, 188.33 cm and 188.42 cm respectively. According to the t-test analysis a significant difference between actual values and calculated values could not identified in 5% a level. Finally it is concluded that the in-built equation (Groundwater balance Equation) in the developed model is acceptable for the site at Mapalana. Thu, 23 Oct 2008 00:00:00 GMT http://ir.lib.ruh.ac.lk/handle/iruor/12826 2008-10-23T00:00:00Z