TRAIL ROAD LANDFILL SITE MONITORING USING MULTI-TEMPORAL LANDSAT SATELLTE DATA

摘要

The disposal of the solid wastes in landfill sites should be properly monitored by analyzing samples from soil, water, and landfill gases within the landfill sites. Nevertheless, ground monitoring scheme requires intensive efforts and cost, and sometime it is difficult to be achieved in large geographic extent. Remote sensing technology has been introduced for waste disposal management and monitoring effects of the landfill sites on the environment. This paper presents a case study to evaluate the use of multi-temporal remote sensing data to monitor and assess the effects of landfill sites on the environment. The study area covers the Nepean and Trail Road landfill sites (the main municipal waste disposal site for the city of Ottawa). The Nepean landfill site was opened in 1960s, accepted waste until 1980s and finally capped in 1993. With the increasing amount of waste disposal, the Trail Road landfill was then constructed and was in operation in early 1980. The Trail Road landfill, which is still in operation, is comprised of four phases developed sequentially. Thirteen bi-yearly multi-temporal Landsat satellite images acquired during July and August from the year 1985 to 2009 are used to calculate the Soil Adjusted Vegetation Index (SAVI) and the Land Surface Temperature (LST). The differences of the LST between the landfill sites (due to the release of the landfill gases within the landfill site) and the surrounding areas are analyzed. Furthermore, the LST of the landfill sites are monitored to assess the decomposition activities of the waste disposal. Preliminary data analysis reveals that the LST of the landfill site is higher than the immediate surrounding areas and the air temperature during the decomposition process by up to 9 deg C and 14 deg C, respectively. In the Trail Road landfill site, the LST of the active phases of the landfill site is higher than the closed phases of the landfill site by around 3 to 5 deg C. The SAVI is used to investigate the healthiness of the vegetation of the immediate surroundings areas. It was found that the closer the location of the vegetation to the landfill site, the comparatively lower SAVI values are found. The lower SAVI of the surrounding vegetation can be explained due to the existence of the leachate produced from the decomposition process.