A coupled framework for estimating pollutant emissions from open burning of specific crop residue: A case study for...

Crop residue open burning is considered to be one of the main sources of pollutant emissions from rural areas. It is necessary to accurately establish an emissions inventory of specific crops which could reflect the specific spatiotemporal distribution characteristics of crop residue burning emissions. However, the information for emission estimation of specific crop in each province and year is seriously data-deficient, resulting in a large uncertainty in the emissions inventory. In this study, taking the open burning of wheat residue as an example, we propose a framework for estimating pollutant emissions for specific crop residue by combining phenological information, land use data, field investigation/statistical data, and fire detection information. The wheat residue open burning proportion (OBP) and the corresponding pollutant emissions were estimated for each province in mainland China from 2003 to 2019. The national average OBP and emissions of wheat crop residue open burning first increased and then decreased during this period, with the peak in 2012. The gridded spatial distribution showed that high-emission areas were mainly concentrated in central-eastern China, and the emission areas gradually shifted from south to north from April to September. The change of daily emissions from large-scale concentrated emissions to small-scale emissions demonstrated that straw open burning prohibition policies were effective in reducing the annual emissions and peak daily emissions. This study provides a promising method for the combination of data from multiple sources to estimate open burning of crop residues. The method can be used to obtain accurate and detailed emissions data to support research into biomass burning and the development of targeted mitigation strategies.