Development of the satellite Remote Sensing
activities in Sri Lanka
General information about Sri Lanka
Sri Lanka is an Island situated approximately 60 to 100 North in latitude and 700 to 820 E in Longitude in the Indian Ocean. Total land area amounts to about 65,500 sw kilometers, with a population of about 17 million. Sri Lanka is an agricultural country with rice being its staple food. The other major agricultural products are Tea, rubber and coconuts. Topographically the country is divided into three zones, the lowlands situated between 0-300 meters amount to about 78% of the land, the intermediate zone between 300-900 meters amount to 20% of the land and the central highlands over 900 meters amounts to the balance 2% of the land. The highest mountain in Sri Lanka, Pedurutalagala is about 2525 meters. On the basis of rainfall the Island is divided into two major ecological systems the wet zone and the dry zone. The dry zone is very arid and it receives only very little rain. Hence in this region rain water has to be stored for agriculture. For this reason in this zone one witnesses a large number of tanks and irrigation systems built by our ancient kings to store and distribute the water.
Air Photography
The country is fully covered on the 1:40,000scale of photography during the period 1956-60. since the Survey department possessed a new air craft in 1980, (Cessana Eagh 421C) the entire Island had been re-photographed on the scaled o 1:50000, 1:20000 and 1:10000. These photography is utilized for photo-interpretation and for photogramatic mapping. There is also much user demand for these photography.
Topographical maps of Sri Lanka
The very first series of topographical maps of Sri Lanka on the scale of one inch to the mile (1:63,360) was produced during the period 1897-1925. These are 72 maps on this scale covering the Island.
Over the years, the updating process of the one inch Topographicl map series has fallen into arrears. Also the need to adopt a metric scale, demanded the shift to produce a new implementation of the Agricultural Base Mapping Project (ABMP) for the production of the 1:50,000 scale Maps, with better data content and contour interval to cover the entire Island. Though originally intended to complete the production of this map series in 5 years for 1980-85, due to constraints, this shall be completed only in this year. In this new series of topographical maps, the preparation of the manuscript was by photogrammetry.
From the beginning the Survey Dept. has developed its photogrammetric capabilities for mapping, today the Air Survey Branch is a well equipped organisation within the survey dept. with its own survey air craft, on RC 20 Aerial camera, a photo laboratory, several precision photogrammetric plotters and a group of trained photogrammetric operators and other technical staff.
Land use mapping in Sri Lanka 1956-60
First aerial photo cover during 1956-60 was used for the preparation of this series of land use maps. With the one inch topo maps as a base, the photographs were reduced and mosaiced together. Agricultural landuse and forest types were derived by photo interpretations; and intensive field verifications. The above completed type boundaries were transferred to the respective mosaics. The resultant efforts was s series f 72 maps covering Sri Lanka published in 1958 with complete classification of the agricultural land use and forest types included in the map legend.
The Sri Lanka -Swiss project for Land Use Mapping
With the launching of the Earth Resource satellites in the Seventies, the Sri Lanka Government, requested to assist in the introduction and the use of satellite remote sensing technology for the acquisition, mapping and monitoring of the urgently needed basic spatial resource data.
The Swiss government attached this responsibility to the Remote Sensing Section of the Department of Geography, University of Zurich to develop the technology for the use of satellite remote sensing imagery for the resource data acquisition in Sri Lanka. The emphasis for the beginning was for the use of the available resources, and the development of the application of medium level technology for the data acquisition. From our point of the sustainability of the project, it was considered very important :-
The establishment of a central agency, the centre for remote sensing (CRS) for co-ordinating and carrying out all planned mapping activities and use assistance programmes.
Training of local counterparts and CRS staff.
To build up closer links with the respective agencies interested in adopting remote sensing techniques in their work.
The implementation phase of the project commenced in 1980.
