关键词: 人工表面, ChinaCover, 城市群, 胡焕庸线, 遥感监测

Abstract:

Chinese government pulished ‘National New Urbanization Plan (2014-2020)’ (Plan for abbr.) in 2014. In the Plan, some problems were proposed, including ‘urbanization of land’ is faster than the ‘urbanization of population’, and the extensive and inefficient use of settlements, ‘the potential of urbanization could be developed in middle-western China’, ‘Urban spatial distribution and scale structure are unreasonable, and do not match the resource and environmental carrying capacity’. Also, the Plan suggested ‘effectively controlling the scale of new construction sites in mega cities’. Based on the multi-temporal landcover data obtained from time series remote sensing data, this article extracts and quantitatively evaluates the information of built-up land changes nationwide. Based on this, the trend of changes in per capita built-up land area of all provinces across the country and the seven major Metropolitan region are further analyzed. The built-up land changes validate and support some standpoints in the Plan, and provide data support for the evaluation and planning of urbanization in China. According to the ChinaCover dataset, the total area of built-up land in China was 290 700 km2 in 2015, of which 251 000 km ² for settlements, 30 900 km2 for transportation land, and 8 800 km2 for mining field. In 2015, the total area of built-up lands increased by an annual average of 6 600 km2 compared to 2010, with an average annual growth rate of 2.57%, which is an increase over the annual average increase of 5 500 km2 from 2000 to 2010, but the growth rate is a slowdown (2.70%). Overall, the growth rate of the built-up land in most provinces in China has continued to increase in the past 15 years. This reflects the ‘urbanization of land’ is faster than the “urbanization of population”, and the extensive and inefficient use of settlements. Meanwhile, the economic transition is proved by analyzing the relation between GDP and built-up lands, which shows the urbanization influences GDP more during 2000-2010 than 2010-2015. The rapid development of western provinces primarily shows the high urbanization potential of the middle and western China. The monitoring in the 7 major Metropolitan region indicates that the pace of urbanization in China has been accelerating in the past 15 years, and in particular, the expansion rates of some late developing Metropolitan region are mostly fast, while the rate of the developed Metropolitan region have slowed down due to the requirements such as ‘effectively controlling the scale of new construction sites in mega cities’, but the problem of ‘Urban spatial distribution and scale structure are unreasonable, and do not match the resource and environmental carrying capacity’ is still existing.

Key words: built-up lands, ChinaCover, Metropolitan region, Hu’s line, remote sensing based monitoring