Mapping and Inventory of Coastal Wetlands in Sri Lanka: Colombo / Putalam Belt, Western Coast, Sri Lanka

Sri Lanka became a Ramsar Convention member state in 1991 (CEA 1994). Many of the wetland sites in Sri Lanka are today being recognized as important, both regionally and globally and three have been declared as Ramsar sites of International Importance . The wide array of natural and man-made wetlands in the island has contributed to a rich aquatic biodiversity and overall it harbours about 45 lagoons linked to 101 river basins. During the last 15 years, the importance of wetlands and their management has gained increased recognition in Sri Lanka, as it has in many parts of the world. This was reflected by initiatives during Asian Wetland Inventory that identified 41 wetland sites of international importance in Sri Lanka, and the Wetland Atlas of Sri Lanka prepared by the CEA in 1999 providing an overview of the identfied wetlands.

The present study is propose to map, characterize urban wetlands in Colombo-Puttalam Belt, on the western coast Sri Lanka, and to use this new information to spatially model and assess risks and wise use scenarios, taking into account the environmental conditions and the natural resources upon which a large population on the western coast of Sri Lanka is dependent upon.A multiple scale inventory using multiple data sets of varied spatial and spectral resolution will be adopted in order to ensure high accuracy. The study is based on potential of spatial data sets to map, characterize and classify coastal wetlands. However, other aspects governing wetland systems which refer to change in vegetation structure and land use pattern, expansion in agricultural activities, population rise, fishing statistics, will be considered for spatial modeling of wetland complexity and conservation prioritization.

Issues of concern

Degradation of wetland ecosystems has gained pace as the result of the influence of high anthropogenic pressure resulting from accelerating and rapid urban growth over the last 50 years.The main socio-economic factors driving wetland loss includes excessive fishing, population expansion, poverty, lack of awareness, poorly informed public policies and socio-political structure. Another phase of wetland degradation is anthrpogenic influence in the form of domestic refuse, sewage and industrial wastes, and sediment and silt loads. However ,we have identified certain aspect to be addressed in the proposed study

• The transformation of coastal area into shrimp farms, salt pans
• Shrinking in the coral reef zone
• Low rates of Mangroove regeneration
• Extensive fishing practiced in the region
• Motorized and destructive fishing techniques
• Expanding population and the overuse of the natural resources
• Influx of migrants from the east
  

Study Area

Sri Lanka is Tropical Island geographically lying between 5 .54 0 N to 9 .52 0 N and 79 .39 0 E to 81 .53 0 E and falls in the Asiatic monsoon region. The total land area is about 65000 km 2 (SAARC SOE Report Sri Lanka, 2002).The overall climate is hot and humid climatic with certain microclimatic variations. The average annual temperature is around 32 0 C in lowlands and about 21 0 C in uplands. The rainfall pattern also shows significant variability on seasonal and regional domains based on topographical features. Nearly one third of the island is covered by natural vegetations while rest shows wide variations in agro-ecological regions within the country. The change in temperature due to latitude is in significant in Sri Lanka, however the differences with regard to altitude are pronounced (SAARC SOE Report Sri Lanka, 2002). Colombo-Puttalam belt is coastal belt in the North-western Province (Puttalam Lagoon and Mundel Lake) of Sri Lanka. It covers three major provinces Colombo, Gampaha and Puttalam The stretch has few significant coastal wetlands systems viz., Puttalam Lagoon Kalpitiya Lagoon Mundel Lake Chilaw Lake Anawilundawa Ramsar Site Negombo Lagoon Muthurajawela Wetland Sanctuary

Study Area-Western Coast Sri Lanka ( Colombo Putalam Belt)

Objectives

The objective of the present study is inventory and map coastal wetlands on the western coast of Sri Lanka. This fundamental baseline data, and a comprehensive knowledge base of the current status of these wetlands areas, and associated trends and risks, will provide a basis for their sustainable management and conservation. The main objectives include: site specific review/overview, developing collaborations and consultation with stakeholders, development of maps and inventory database, validations of methods and results spatial modeling of risk analysis and identification of ecological indicators. The activities include; delineation of wetland boundaries and classification of wetlands by ecological characteristics, using a standardized classification typology. Analysis of spatial and ecological change and identification of indicators of wetland loss. Three major issues viz., excessive fishing, expanding agriculture, change in mangrove belts, shrinkage in coral reef belt and effects of the shrimp framing have been considered for modeling conservation sites in wetland systems in the coastal belt. It also intends to highlight the significance and potential of risk in coastal wetland areas, in order to promote their conservation and sustainable, productive use

Methods

The methodology proposed for the defined study efficiently correlates the spatial, ecological and socioeconomic aspects in the region. As the representation of the spatial overview we use spatial data of varied spatial spectral and temporal resolution. A multiple scale inventory using multiple data sets of varied spatial, spectral and temporal resolution ensure greater relevance and effective dissemination. Partnerships and collaboration will be developed to access data and information. The methodology is framed to address the key issues of conservation in environmental and developmental context.

The phases of the proposed inventory include:

• Spatial Phase : Spatial data procurement, processing , analysis and classification and change detection
• Ground Data Collection : refers to the field reconnaissance , sample data collection, collection of ground control points and post classification validation
• Spatial Analysis :Integration of spatial and non spatial attributes to define sites for priortisation
• Internet GIS Platform: Web Analysis to generate resource sharing and Internet geospatial interface
  

Expected Outputs:

• Methodological review of the extent of wetland mapping and inventory of coastal wetlands on the western coast of Sri Lanka
• Technical report demarcating appropriate approaches for wetland mapping and inventory at local scale taking into account wetland ecological,hydrological,prioritization, conservation and management issues
• Maps and technical papers representing important wetlands sites
• Identification of drivers governing the change in the wetlands ecology and analysis of temporal change processes.
• Development of a Wetlands Knowledge Base for monitoring, management, and conservation
• Web Enabled knowledge exchange platform and capacity building for wetland mapping and inventory in Sri Lanka

Anticipated users and stake holders

The unique combination of data resources and methodological development represented in this demonstration effort is intended to catalyse or support an international focus on wetland Assessment and Conservation. This will also aid to develop spatial modelling approach for monitoring change in the ecological pattern of wetland systems. The study is designed based on the need assessment of the end users, stake holders, science and management communities involved in the coastal zone management.