To a certain extent artificial land cover affects the structure of terrestrial ecosystems. Understanding how to construct a hierarchical classification system for artificial surfaces and improve the classification techniques for artificial surface extraction, which can provide important information for the construction of healthy living environments and sustainable development strategies for Asian cities, and the implementation of the Belt and Road Initiative.

Dr. KUANG Wenhui and his team from Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, explained population aggregation and economic development level as well as their impacts on the health of the environment in the subwatershed.

They developed a new approach to extract the pixel components of subclass artificial surface cover based on GlobeLand30, and produced products of proportional urban built-up areas, impervious surface and vegetation cover components in Asia in 2010 with 250-m resolution.

The intensity and proportions of urban impervious surfaces in Asia exhibit a three-level (continuous, scattered in central cities and indeterminate) gradient distribution pattern from east to west.

The sub-watershed area in Asia with a proportion of urban impervious surface area greater than 25% accounts for 0.35% of the total land surface area of Asia; such subwatersheds are mainly distributed in East Asian countries. The ecosystems of the downstreams of the major watersheds, to some extent, have been affected by urban impervious surfaces.

Differences in the urbanization, industrialization and economic development levels among countries in Asia cause significant differences in urban built-up areas as well as component structures of impervious surface and green space inside urban built-up areas.

This work was supported by the National Natural Science Foundation of China (Grant Nos.41371408; 41371409), the National High Technology Research and Development Program of China (Grant No. 2013AA122802), and the State Key Development Program for Basic Research of China (Grant No. 413714082014CB954302).

The related work has been published in Science China Earth Sciences (Kuang W H, Chen L J, Liu J Y, et al. Remote sensing-based artificial surface cover classification in Asia and spatial pattern analysis. Science China Earth Sciences.2016.DOI: 10.1007/s11430-016-5295-7).