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Land cover mapping in mountainous areas is a notoriously challenging task due to the rugged terrain and high spatial heterogeneity of land surfaces as well as the frequent cloud contamination of satellite imagery. Taking Southwestern China (a typical mountainous region) as an example, this paper established a new HC-MMK approach (Hierarchical Classification based on Multi-source and Multi-temporal data and geo-Knowledge), which was especially designed for land cover mapping in mountainous areas. This approach was taken in order to generate a 30 m-resolution land cover product in Southwestern China in 2010 (hereinafter referred to as CLC-SW2010). The multi-temporal native HJ (HuanJing, small satellite constellation for disaster and environmental monitoring) CCD (Charge-Coupled Device) images, Landsat TM (Thematic Mapper) images and topographical data (including elevation, aspect, slope, etc.) were taken as the main input data sources. Hierarchical classification tree construction and a five-step knowledge-based interactive quality control were the major components of this proposed approach. The CLC-SW2010 product contained six primary categories and 38 secondary categories, which covered about 2.33 million km 2 (accounting for about a quarter of the land area of China). The accuracies of primary and secondary categories for CLC-SW2010 reached 95.09% and 87.14%, respectively, which were assessed independently by a third-party group. This product has so far been used to estimate the terrestrial carbon stocks and assess the quality of the ecological environments. The proposed HC-MMK approach could be used not only in mountainous areas, but also for plains, hills and other regions. Meanwhile, this study could also be used as a reference for other land cover mapping projects over large areas or even the entire globe.

Physical stimuli from contacted objects are recorded by skin receptors and are transmitted to neural signals to the cerebrum to generate touch perceptions. Despite numerous studies having been conducted on the link between the physical properties of contacted objects and psychological sensations, factors besides the stimuli themselves have seldom been investigated. The contact method and acclimation to environmental factors, such as temperature and humidity, could affect the functions of responsible receptors, which, in consequence, might affect the touch perception. This study is designed around a series of experiments involving 226 human subjects adapted to the climate environments of six East-Asia cities. The results revealed that the contact method affected the responses of smoothness sensation but not the stimuli discriminations. This agrees with the hypothesis that both the slowly adapting type I (SA1) fiber and the Pacinian afferent (PC) fiber are responsible for smoothness sensation. SA1 fibers can function through passive touch because of a superficial location in the dermis, while PC fibers, which are located deeper in the dermis, are triggered during active touching. The effect of contact method on softness sensation is not significant because the responsible receptor is the SA1 fiber. The effects of acclimation to temperature and relative humidity were also investigated. Positive relationships were found with smoothness perception and negative relationships were found with warmth perception. This suggests that acclimation to temperature and relative humidity can affect the receptor thresholds and, in consequence, affect the touch sensation.

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