HiTIC-Monthly: a monthly high spatial resolution (1 km) human thermal index collection over China during 2003–2020

[摘要] Human-perceived thermal comfort (known as human-perceived temperature)measures the combined effects of multiple meteorological factors (e.g.,temperature, humidity, and wind speed) and can be aggravated under theinfluences of global warming and local human activities. With the most rapidurbanization and the largest population, China is being severely threatenedby aggravating human thermal stress. However, the variations of thermalstress in China at a fine scale have not been fully understood. This gap ismainly due to the lack of a high-resolution gridded dataset of human thermalindices. Here, we generated the first high spatial resolution (1 km) datasetof monthly human thermal index collection (HiTIC-Monthly) over China during2003–2020. In this collection, 12 commonly used thermal indices weregenerated by the Light Gradient Boosting Machine (LightGBM) learning algorithmfrom multi-source data, including land surface temperature, topography, landcover, population density, and impervious surface fraction. Their accuracieswere comprehensively assessed based on the observations at 2419 weatherstations across the mainland of China. The results show that our dataset hasdesirable accuracies, with the mean R 2 , root mean square error, and meanabsolute error of 0.996, 0.693  ∘ C, and 0.512  ∘ C,respectively, by averaging the 12 indices. Moreover, the data exhibit highagreements with the observations across spatial and temporal dimensions,demonstrating the broad applicability of our dataset. A comparison with twoexisting datasets also suggests that our high-resolution dataset candescribe a more explicit spatial distribution of the thermal information,showing great potentials in fine-scale (e.g., intra-urban) studies. Furtherinvestigation reveals that nearly all thermal indices exhibit increasingtrends in most parts of China during 2003–2020. The increase is especiallysignificant in North China, Southwest China, the Tibetan Plateau, and partsof Northwest China, during spring and summer. The HiTIC-Monthly dataset ispublicly available from Zenodo at https://doi.org/10.5281/zenodo.6895533 (Zhang et al., 2022a).

[学科分类] 眼科学