Mapping wetlands of the Pearl Delta Region using multi-temporal ENVISAT ASAR data

Principal Investigator: Prof. Lin Hui

Start Date: 2007/04/18
End Date: 2008/04/19
Type of Grant: Direct Grant for Research (2006-2007)- 2nd Round

Wetlands play an important role in bio-geochemical cycling, flood control and recharging of aquifers. The wetlands of Pearl Delta Region (PDR) and its adjoining areas support a variety of crops, for example, sugarcane, banana, lotus, and so on, which are important economic crops in pearl delta region. Precise information of their nature, extent and spatial distribution is important for monitoring the biological condition of costal wetlands. Synthetic aperture radar, which has the ability to penetrate cloud, permits regular and repetitive observation of the wetlands.

We propose to develop a new approach to carry out the wetlands mapping using multi-temporal microwave remotely sensed data. The primary objectives of the proposed research are to: 1) Improve coastal wetland characterization (cover type and fraction of vegetation, soil and water estimate) using field data and optical and radar remote sensing data; 2) Investigate radar backscattering process associated with each types of the coastal wetlands; 3) Identify optimal combination of radar data (with different polarization and incidence angle) for coastal wetlands classification; 4) Develop a new classification method for wetland mapping; 5) Evaluate the quality and reliability of all products developed from this project using field data, optical data, and other independent reference data.

Deliverables from the project should greatly contribute to a better understanding of coastal wetlands ecosystems and towards establishment of a long-term monitoring capability in the South China-Sea. Because the wetlands of South China-Hong Kong region is typical of many wetland ecosystems in the world tropical and subtropical regions, especially areas under consistent clouds and rain, implementation of this project can serve as a template for many regions of the world.