Abstract:
Flood prone areas are rapidly growing urban areas in Sri Lanka. Land use activities are
converting natural landscapes for human use, as urban land use change, both
geographically and demographically, the flood hazard risk and exposure is very high. This
study aims to understand the urban land use changes in the flood prone area with special
reference to Batticaloa Municipal Council area (BMC) during the period of last two
decades. Specific objective of the study is to develop a Geographic Information System
(GIS) and Remote Sensing (RS) based tools to identify land use changes. Both primary and
secondary data used to fulfill the objectives. Structured questionnaire survey has been
used to collect primary data through random sampling method. Landsat multi spectral
images of 1980, 1995, 2005 and 2015 were used as secondary data and analyzed through
supervised classification process by Erdas imagine 9.1. In addition overlay, proximity and
image analysis were used to identify the land use changes according to flood risk area by
Arc GIS 10.1. Past considerable events were drawn by indigenous people with the use of
Participatory Rural Appraisal (PRA) tool timeline technique. Sector wise land use changes
were identified using Chi square analysis and existing situation was noticed with SWOT
analysis.
Land use activities were classified into buildup area, vegetation, cultivated land and water
bodies. The results show that the buildup areas are highly increasing from 830.8ha in 1980
to 2450.86ha in 2015. Vegetation in 1980 was 49% it has reduced up to 12% in 2015.
Cultivated land during 1995 to 2005 has reduced from 32% to 20% and further reduced to
17% in 2015. Severe flood damages were identified in 1999, 2009 and 2011 through the
participatory historical mapping and there are relationships between settlements,
administrative, agricultural land use changes in flood prone areas showed by the Chi
square results. Finally, considering the land use change has occurred in the flood risk
zones cause many impacts like improper land use, land filling and land encroachment.
Study provided with the suggestion that proper land use planning and management is
needed to reduce the flood risk in urban areas
