Trends of wetland reclamation in Colombo Metropolitan Region in Sri Lanka and strategies to minimize adverse impact

A G Amarasinghe

doi:10.4038/sljass.v9i1.7145

Abstract

The disappearance of wetlands in the Colombo Metropolitan Region (CMR) in Sri Lanka is increasing at an alarming rate since the 1980s. Both wetland and urban lands in CMR have become important geographical areas in the country both socio- economically and politically. CMR serves as economic and administrative hubs in the country. This background causes to accumulate population and infrastructure facilities in and around the CMR. Therefore, urban development demands more land for the urbanization process. Reclamation of wetland adjacent to urban areas has become a common solution to the high demand for land in CMR, Sri Lanka. The main objectives of this study are to find the trends of wetland reclamation in CMR and develop effective and efficient strategies to minimize the adverse impact of wetland reclamation process. The primary data was collected from two methods namely, interpretation of air photographs taken in 1959 and satellite images of 1989 and 1918 which appeared on Google Map and field surveys. Secondary data was collected from reviewing literature. Results of this study indicate that, the 63.46% of the wetland in CMR have disappeared during the last 59 years since 1959. The overall wetland reduction rate is higher since 1989. In addition, there is a trend for the disappearance of the wetland extent which is changing spatially and temporally.

Highlights

Wetland reclamation has become a common practice in almost all urban areas around world, in fast developing regions such as South, South East and East Asia (Ramsar, 2016, 2018)
The basic statistical methods and facilities available on Geographical Information System (GIS) and Remote Sensing (RS) technology were employed to analyze the data gathered from the map interpretation and field survey
It is clear that the 63.46% of the wetland in Colombo Metropolitan Region (CMR) have disappeared within the last 59 years since 1959

Summary

Introduction

Wetland reclamation has become a common practice in almost all urban areas around world, in fast developing regions such as South, South East and East Asia (Ramsar, 2016, 2018). The remaining lands that can be converted for urbanization activities in many urban areas around the world including Sri Lanka are wetlands. A significant and speedy urbanization was projected by the United Nations (1989) in the less developed countries even in the 1980s. The demand for land due to the accelerated urbanization process in Sri Lanka is significant Since urban development plans are not implemented as scheduled, sprawl urbanization process can be seen in Sri Lanka creating environmental, socio-economic, political and cultural issues (Ranasinghe, 2014, Ranaweera & Rathnayake, 2017). The lack of exact data and information on the trend of wetland reclamation, special and temporal distribution of reclaimed land and the identification problems associated with wetlands have become the main problems in the field of land reclamation in Sri Lanka

Objectives

Methods

Results

Conclusion