Urban Land Use Changes in Flood Prone Areas During Last Two Decades: A Study of Batticaloa Municipal Council Area

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