Assessing Development Pressure on Environmentally Sensitive Areas within Kotikawatta-Mulleriyawa Pradeshya Sabha, Sri Lanka

Abstract

History has shown that urbanization is a key driver of growth. However, it is evident that the pressure it generates upon the land leads to an inappropriate land use change, and especially in environmentally sensitive areas. Kotikawatta- Mulleriyawa is one of the local government areas located at the fringe of the Colombo-Capital City which is a greater planning area in Sri Lanka, experiencing the fastest growth during the past two decades with rapid conversion of wetlands and low-lying areas. The urban planning attempts to regulate the land use conversion through identification of zones which has not been successful due to the demarcation of development zones without scientific analysis. As a result, environmentally sensitive lands had been converted and continuing to be used for urban activities leading to the reduction of wetlands by 8%, and 10% respectively in the decades 2000 and 2010 and by 5% during last three years. Therefore, it is pertinent to conduct an analysis, based on systematic indicators to identify areas with high risk and thereby identify the most suitable areas for development. This research attempts to identify the risk areas in Kotikawathta-Mulleriyawa utilizing Development Pressure Index (DPI) and Environmental Sensitivity Index (ESI) calculated based on 12 parameters and required data had been selected based on those parameters. The multi-factor 2 weighted summation method then deployed to evaluate the magnitude of the development pressure and environmental sensitivity and the risk levels had been derived by combining the weighted DPI and ESI. Geospatial Technology Applications such as GIS and multi-criteria analysis had been used for the study and the findings revealed that 18% of the area was identified as a very high risk area. Approximately 43% of the KotikawattaMulleriyawa Pradeshiya Sabha Area was identified as high and very high risk areas which are not suitable for development. Further, this paper introduces a scientific methodology to identify the magnitude of urban pressure and the sensitivity of the environment, for the demarcation of zones with high risk, enabling the decision makers to target such areas and to come up with strategic methods to address them.