[H-TT14] Geographic Information Systems and Cartography

[HTT14-11] Changes in the landscape pattern of the Muthurajawela Marsh and Negombo Lagoon Sri Lanka: Socio-ecological implications

*SUMUDU DARSHANA ATHUKORALA ARACHCHIGE¹, Yuji Murayama², Bunkei Matsushita², Ronald C. Estoque³ (1.Graduate School of Life and Environmental Sciences, University of Tsukuba, Japan, 2.Faculty of Life and Environmental Sciences, University of Tsukuba, Japan, 3.National Institute for Environmental Studies, Japan)

Keywords:Wetland, Muthurajawela Marsh and Negombo Lagoon, Socio-ecological, Spatio-temporal analysis, Urban ecology, Remote Sensing

Rapid population growth and uncontrolled urban expansion are important drivers of land-use changes, posing critical challenges towards the sustainability of urban ecosystems. Urban wetlands ecosystems (UWEs) play important social and ecological roles but are often affected by urban landscape transformation processes. The primary purpose of this research was to understand the effects of urbanization on one UWE in Sri Lanka to help wetland management, land-use planning and in the protection of UWEs in the country and elsewhere in the world. The western region of Sri Lanka is one of the emerging growth centers in the country where natural environment and wetland ecosystems have been under extreme pressure. In this study, we developed a framework to evaluate the changes in the spatial configuration of the Muthurajawela Marsh and Negombo Lagoon (MMNL, an important UWE in Sri Lanka) during the period of 1997-2017. Such a framework cuts across various disciplines, including environmental history, urban ecology, wetland science and GIScience and remote sensing. More specifically, this research focused on understanding and assessing the current potential spatial stress on the MMNL due to human interference. We found that the MMNL has experienced rapid landscape transformation over the past 20 years. The area of marshland and mangrove in the MMNL has decreased by 48% and 24%, respectively, while the area of built-up has increased by 79%. We also found that the most marshland lost due to built-up expansion. Indeed, rapid population growth and uncontrolled urban expansion have impacted the MMNL. Such a landscape transformation of the MMNL might have considerably affected the biodiversity and ecosystem services of the area. Hence, there is a need for land-use planning strategies that could protect and enhance the biodiversity and ecosystem services in the area and, at the same time, guide actions towards the sustainability of this important UWE in the country.