Abstract:
The objectives of this study were to create the conversion equation to convert 1inch: 1mile reference of irrigation tanks to National Coordinate system and create a database using Arc GIS 9.3 software through documentation and to recognize the distribution pattern of irrigation tanks in Vavuniya district, Sri Lanka. Secondary data of 611 tanks of tank command area, catchment area, capacity, bund length, number of sluice, number of farm families and the coordinates of the location of tanks were used. Mapping the irrigation tanks was performed using the converted coordinate system with the help of a created mathematical equation in Arc GIS 9.3. The average tank density of Vavuniya district was one tank per 2.68 km2. This study initiated the maintenance of a database for the irrigation tanks in Vavuniya district. The distribution pattern indicated the importance of the irrigation tanks in this district. Documentation and mapping would be helpful for planning to provide effective and efficient management. The outcome of this research would be useful especially to the irrigation department and the Department of Agrarian Development. Further, measures should be taken to manage these tanks as they are the only surface water resource of this district.