|
|
|
Oceanography / Meteorology
|
Feasibility studies of changes in Coastline, Sri Lanka
L.L.S. Roshani Gunasekera.
Survey Department, Sri Lanka.
Introduction :
Sri Lanka coastal belt is subject to constant changes due to internal as well as external influences. For proper management of the coastal belt a continuing study of these changes is essential. Coast management is important for such activities as economics, development, tourism, planning research, science and education etc.
Firstly, this paper studies periodic changes that have taken place in Sri Lanka coast line.
Secondary, it depicts in statistical from the periodic changes in area where such changes are heaviest.
Thirdly, it indicates what technical steps need to taken for a proper study of the effects on coastal habitats due to changes in the coast lines. The content of this paper visualizes the periodic changes in the coast line and shows how a study of their influences on the coastal habitats could be undertaken with the criteria indicated.
Monitoring of coast line changes:
Here, a study in made of the comparative changes in the coast line by visual analysis of data with the help of maps prepared by Sri Lanka Survey Department. Maps on the scale of 1:500,000 prepared using one inch to one mile topographical mapping of 1924 -1960 period were utilized as the data source. 1:500, 000 scale maps subsequently prepared using 1983 Landsat imagery and the map of Sri Lanka based on IRS images of 1992 were thereafter used to compare the coast line variations. All these data have been compared by simple visual analysis the results of which is shown in figure 1.0
Thus a simple conclusion can be arrived at as what the changes in the coastal belt were during the 1960s, 1980s. In this analysis Weligama Bay area situated at Southern Coastal belt was selected for study as it was subject to comparable variations. Also some other coastal areas Unawatuna, Beruwala have changed, during the period.
Figure 1
The aerial photographs of 1:20,000 in 1983 and in 1965 were used for the purposes of further comparison and statistical presentation of the variation in the area. The results obtained are shown in figure 2.0
Figure 2
|
|
|
|
|
|
|
