spatial estimation of methane emission using remote sensing and dndc model in major rice growing areas of tamil nadu

Abstract

ABSTRACT newlineSPATIAL ESTIMATION OF METHANE EMISSION USING REMOTE SENSING newlineAND DNDC MODEL IN MAJOR RICE GROWING AREAS OF TAMIL NADU newlineBy newlineN.S.SUDARMANIAN newlineDegree : Doctor of Philosophy (Agriculture) in Meteorology newlineChairman : Dr. S. Pazhanivelan, Ph. D., newlineProfessor and Head, newlineDepartment of Remote Sensing and GIS, newlineTamil Nadu Agricultural University, newlineCoimbatore 641 003, Tamil Nadu newlineYear : 2019 newlineA research study on and#8215;Spatial estimation of methane emission using Remote Sensing newlineand DNDC model in major rice growing areas of Tamil Nadu was conducted during rabi newline2017 and 2018 (samba season) to estimate rice area, methane emission and its contribution to newlinemethane flux. newlineMulti temporal Sentinel 1A satellite data at VH polarisation with 20 m spatial newlineresolution was acquired between August to January during 2017-18 and 2018-19 at 12 days newlineinterval and processed using MAPscape-RICE software to generate Rice area and Start of newlineSeason maps. Continuous monitoring was done for groundtruth on crop parameters and newlinevalidation exercise was done for accuracy assessment. newlineGas samples were collected from thirty fields using static closed chamber and newlineanalyzed for field level methane using portable gas analyzer. IPCC Factor, MODIS derived newlineLST T factor and DNDC model were used for spatial estimation of methane emission from newlinesix districts of Cauvery Delta Zone and validated with field level estimates. Atmospheric newlinemethane flux was derived using GOSAT satellite data and correlated with methane emissions newlinefrom DNDC model. newlineSpectral dB curve for rice was generated using multi temporal Sentinel 1A SAR data. newlineA detailed analysis of temporal signatures of rice showed a minimum at agronomic flooding newlineand a peak at maximum tillering to flowering and decreased thereafter. Rice crop expressed a newlinesignificant temporal behaviour and a large dynamic range (-20.65 to -15.12 dB) during its newlinegrowth period. newlineAt flooding, minimum dB values of -22.03 to -17.69 dB and -23.40 to -18.51 dB were newlineobserved during 2017 and 2018. The mean maximum value was found to be -15.12 dB