IMPLICATION OF UNPLANNED URBANIZATION ON RIVER BASINS IN SRI LANKA WITH REFERENCE TO THE UPPER MAHAWELI CATCHMENT AREA

Abstract

Sri Lanka has a total land area of 65,525 sq. km and a population of around 19 million. The landman ratio of the country was 0.34 ha per person in 2000. The central highland rises to about2500m above mean sea level, which counts about 25% of the land area of the country. Landformrange varies from flat to very steep terrain from mean sea level. The rivers that radiate from thecentral hills provide a large hydropower potential and also permit a variety of products inagriculture. This network of rivers contribute to the economy in varies of ways. Among them thewater for the agricultural sector and the hydropower for the energy sector, drinking and bathingfor the domestic sector, water for the industrial operation and recreation are the major ones.

River is played very important role in emerged of the town as very essential resources water forthe urban area, supply of infrastructure facilities easier than hill slopes. Historically the ancientcity was emerged on low land of the river basin such as Euphrates, Nile etc. Like wise the firstcapital city of Anuradhapura in Sri Lanka was established on the Malwatu Oya stream. Presentlymost of the cities emerged on river with several sub systems of other resource. As a result ofunplanned expansion of the urban settlements on river basins faced sever problems of downstream and upper catchment development.

This paper attempts to introduce the concepts and major issues of the rivers and proposed toguidelines for planned development on river basin in order to minimize environment pollutionand adverse implication of haphazard development on hilly slopes. It contributes the plannedurbanization on river basins and strengthening the national economy and prosperity as a subsystem of whole systems