A study of the present and potential in Sri Lanka

Abstract

The Government had initiated a National Agricultural, Food and Nutrition Strategy to-assess Sri Lanka's agricultural and food situation and establish priorities for sectoral development. Since the plan involves the use of land, a computerized Land Information System was set up to facilitate the analysis and evaluation of Land use in Sri Lanka. A Radio Shack Model II micro-computer was used for this purpose. Data on Soils, climate, topography and present land use were fed into the computerized data bank. The grid cell system of data storage was used. The dimensions or a grid cell are 1.05 x 2.1 Km covering an extent of 224 hectares. The final maps are plotted to a scale of 1:500,000. The soi1 data were obtained from the manuscript copies or reconnaissance soli maps drawn to a scale of 1:63,630 available at the Land Use Division. The climatic data were obtained from the agro-climatic data and rainfall probability maps produced by the Land and Water Use Division in 1976 and 1983 respectively. Slope data were compiled with the help of contour Lines on Topographic maps of scale 1:63,360. Data on present land use were obtained from three sources viz. (a) Survey Department (1981) 1:100,000 and 1:50,000 scale maps of Polonnaruwa, Batticaloa, Kandy and Colombo(final maps) and Puttalam, Gampaha, Kegalle, Kurunegala, Badulla, Ampara and Matale Districts (prelimlnary maps) (b) Land Use Division (1980 to 1983) 1: 63,360 and 1:50,000 scale maps of Matara, Nuwara Eliya, part of Ratnapura and Hambantota Districts(c) Huntings Survey Corporatlon (1956) 1: 6 3,360 scale maps for the balance Districts updated by date from Topographic sheets of 1970s and data on Irrigation schemes implemented by the Irrigation Department and Mahaweli Authority. Data on soils, climate and topography were assessed to determine suitabilility of lands for (a) rainfed annual crops (b) irrigation upland annual crops (c) rainted paddy under puddle conditions (d) irrigated paddy under puddled conditions (e) rainfed sugar cane (f) irrigated sugar cane (g) rainted minor perennial crops. Four classes of suitability as recommended in the FAO Framework for Land Evaluation Viz S1Highly Suitable, S2 Moderately Suitable, S3-Marginally Suitable and N Unsuitable were recognized in this exercise. Tables of district wise of land suitability classes were also complied. Secondly the present land use was analyzed with respect to the suitability classes. The map complied for this purpose shows locations at which the analyzed land use is practised giving the symbol of the suitability class. A table giving the district wise extents is also complied. Thirdly the potential locations for expansion of the considered land use is compiled. Only locations of class S1 and S2 suitability are considered. Lands under forest reserves, wild life parks, land earmarked for Mahaweli and other development projects and other reserves are shown with separate symbols F, P, M, D and R respectively for class Sl lands and f, p, m, d and r for class S2 lands. A districtwise extents table too is compiled.