Urbanization on stream corridor ecosystem: case of meda ela & pinga oya tributaries in upper mahaweli river, sri lanka

Abstract

Abstract: Impacts caused by urbanization on stream corridor eco-systems are enormous. In Sri Lanka stream corridors can be considered as one of the major sensitive eco system and that has been threatened by urbanization. Objective of this study is to analyze the stream corridor ecosystem stresses due to urbanization. Nature of the problem and impact in this study were analyzed through collected data from different types of surveys such as chain, vegetation, Solid waste, stream loads, water test, stakeholder interviews and observations. Ecosystem Stresses have been analyzed as follows: Private ownership (90%) of the stream corridor boundary lands and their activities are the major threat for the stream corridor ecosystem and created several impacts. Artificial modifications in stream corridors are the major problem created by land ownership close by the streams and it effected to structure and process in seven ways and affected 14 numbers of elements, parts and values in the stream corridor ecosystem. Stream dwellers waste handling behavior was identified as a second problem for the stream corridor it negatively effects ecosystem structure and process in four different ways and affected 12 elements, parts and values. Vegetation changes in stream corridor negatively affect to stream corridor structure in 2 ways and affected to elements and values in the stream corridor ecosystem. For sustainable stream corridor ecosystem the government give more power to relevant authorities to take legal actions for demarcate the stream corridor boundary line at least in urban premises and implementing some awareness programs in headwater catchments are recommended