Methane hotspot localization and visualization at a large-scale Xi'an landfill in China: Effective tool for landfill gas management

The variation characteristics and influence factors of methane emission at Jiangchungou landfill, one of the largest landfill in China, has been investigated by a one-year field monitoring campaign during 2015–2016. The methane concentration above the landfill surface varied widely from negligible to 33,975 ppm. At least 75% of the methane concentration values of the sampling points are lower than the allowed limit (500 ppm). More than 95% of the high concentration zones (>500 ppm) were located in the temporary cover area (TA). Several environmental factors were found to be related to the variation of the concentration values. A clear correlation was observed between barometric pressure and exceeding-standard areas with a correlation coefficient of −0.743 (p 1.5 mm) with a good construction quality control are expected to provide better performance at this site. •Full-scale methane distribution was monitored for a year at large landfill site.•Concentration variation is 5 orders of magnitude on different area.•Meteorological factors affecting exceeding standard areas were investigated.•Gas wells have greater effect on methane emission from loess rather than on HDPE.•Methane concentration on geomembrane defects was higher than that on loess surface.