Estimation of methane emission from a deep-water rice field using Landsat TM and NOAA AVHRR: a case study of Bangkok Plain

A rapid increase in the concentration of greenhouse gases (GHGs) aggravates global warming of the Earth's atmosphere. It is necessary to monitor the e mission rate as well as emission quantity of methane as a major component o f GHGs. The objective of this study is to develop mathematical models for t he estimation of methane emission from a deep-water rice field, using infor mation extracted from satellite images. The methodology proposal in the stu dy consists of two models: firstly, the true ground data of the monthly bio mass of rice and average methane emission rate were analysed to set up the methane emission rate model; secondly. the biomass of rice and Various refl ectances of the wavelength obtained from satellite images were investigated . It has been found that Landsat TM band 3, band 4, band 5, band 7 and the normal differential vegetation index as well as the National Oceanic and At mospheric Administration AVHRR band I. band 7 and NDVI are well related to the biomass of rice. which can be used to estimate the biomass of rice, the so-called remote sensing (RS) biomass model. Finally the estimation of met hane emission can be manipulated by using the methane emission rate model c oupled with the RS biomass model based on data from satellite imageries. Co mparison between estimated methane emission from satellite images and exper imental methane emission data measured at the Prachinburi Rice Research Cen ter reveals that the methodology proposed can be used to estimate methane e mission from a deep-water rice field with satisfactory accuracy, particular ly during the reproductive stage of rice and maturation.