Ranjana U.K. Piyadasa, Gayani Ranasinghe
Land is one of the most important natural resources for the survival and prosperity of humankind, and it is the platform on which human activities take place. The terms land use and land cover are not synonymous and the literature draws attention to their differences so that they are used properly in studies of land use and land cover change. However, the distinction between land use and land cover, although relatively easy to make at a conceptual level, is not so straightforward in practice as available data do not make this distinction clearly all the time, a fact that complicates the analysis of either one of them. Taking into account the available land use data, this study is carried out to explore both land use and land cover change from 1983 to 2013 of the Bentota River basin located between the Western and Southern Provinces of Sri Lanka. Changes in both the qualitative as well as the quantitative characteristics of land use are described considering the extent of land use and the level of detail conditioned by the spatial level of analysis and the availability of requisite data. Temporal mixed land use diversity of the area was examined calculating land use ‘entropy’ values for different time periods. Findings indicate that 80% of paddy lands of the Bentota basin have been abandoned and converted into marshes, grasslands and scrubs. Tea and cinnamon are the emerging crops, while rubber and coconut lands in the area are seeing a reduction. The level of mixed land use diversity of the area during the last three decades is similar. Future land use activities of the area will consist of water retention areas, commercial use, recreational use, and tourist activity use due to the upcoming Dedduwa Lake Tourism Development Project.
Keywords: Entropy value, Land use and Land cover change