Abstract: Mountain greenspace is a typical type of urban green land landscape in Karst mountain cities, which plays a significant role in improving the urban ecological environment and promoting urban ecological service in Karst mountain cities. We analyzed the relationship between mountain greenspace and the distribution of cold points of urban heat island effect in Anshun City, a typical Karst mountain city in central Guizhou Province. We used cold/hot spot analysis and the thermal infrared remote sensing images and urban landscape structure spatial data in 2011 and 2016, based on the inversion analysis of urban heat island effect and the spatial temporal distribution characteristics of its intensity. We further revealed the cooling effect of mountain greenspace on urban heat island. The results showed that the average retrieved land surface temperature in Xixiu District of Anshun City increased by about 4 ℃ from 2011 to 2016, based on the results of Landsat thermal infrared remote sensing data inversion of surface temperature. The heat island effect in the main urban area showed an increasing trend, whereas the overall heat island area showed a decreasing trend. The green island area was mostly distributed in water and mountain greenspace. The mitigation effect of mountain greenspace on the heat island increased year by year. The cold/hot aggregation area showed an increasing trend. About 40%-50% of the cold accumulation area was contributed by mountain greenspace. The hot aggregation area was mainly composed of construction land and other land-use types. The mountain greenspace area was significantly negatively correlated with the surface temperature at the 500m grid scale, as indicated by the fact that surface temperature would decrease by 0.17-0.27 ℃ for every 10% increase in the proportion of mountain greenspace area in the grid. Our results provide a scientific basis for the mountain greenspace management, urban greenspace planning, and urban thermal environment mitigation in Karst mountain cities.

Key words: mountain greenspace, land surface temperature, urban heat island, hot spot analysis, Karst mountain city.