China has become the world’s largest emitter of SO2 since 2005, and aggressive deployment of flue gas desulfurization (FGD) at coal-fired power plants appeared in China when facing the formidable pressure of environment pollution. In this work, we estimate the annual emission from combustion sources at provincial levels in China from 1990 to 2007, with updated data investigations. We have implemented the method of transportation matrix to gain a better understanding of sulfur content of coal in consuming provinces, which in turn improved the inventory. The total emissions from combustion in 2007 were 28.3 Tg, half of which was contributed by coal-fired power plants. Meanwhile, the industrial boiler coal combustion and residential coal consumed in centralized heating were responsible for another 32% of the total emissions. From 1990 to 2007, annual SO2 emission was fluctuated with two peaks (1996 and 2006), and total emission doubled from 15.4 Tg to 30.8 Tg, at an annual growth rate of 4.4% (6.3% since 2000). Due to the extensive application of FGD technology and the phase-out of small, high emitting units, the SO2 emission began to decrease after 2006. Furthermore, the differences among estimates reported in literatures highlight a great need for further research to reduce the uncertainties with more detailed information on key sources and actual operation of devices.

Spatial structure analysis was conducted on a previously published dataset of DDT species concentrations in topsoil samples from Tianjin, China (p,p′-DDT, p,p′-DDD, p,p′-DDE and ∑p,p′-DDTs). Positive nuggets were observed for all three DDT species and ∑p,p′-DDTs in the four directions modeled. The Nugget–Sill-Ratio values, 0.62, 0.50, 0.63 and 0.58, for p,p′-DDT, p,p′-DDE, p,p′-DDD and ∑p,p′-DDTs respectively, indicated that spatial distribution of DDTs residue in Tianjin topsoil could be characterized with high randomness, on average more than 50%, and less than 50% variance is explainable. Nevertheless, all DDT species have evident spatial structure. These spatial structures are anisotropic, showing more extended transportation along the E–W direction. Furthermore, the spatial structure of p,p'-DDE is more evident than the two other species, i.e. p,p′-DDE showed higher continuity in space than p,p′-DDT and p,p′-DDD, which signs a better mobilization of this species in the soil. Two-dimensional ordinary block kriging was applied to DDT concentrations dataset for mapping purposes. The mean errors were close to zero and the mean squared errors varied from 0.23 to 0.46 log units. The accuracy of interpolation proved to be acceptable for p,p′-DDE and ∑p,p′-DDTs. However, for p,p′-DDT and p,p′-DDD, the interpolation results were accompanied by relatively high kriging errors, due to their high randomness in spatial distribution.