中国城市建设用地转型阶段及其空间格局

1978年改革开放以来,社会经济快速发展不断改变着中国城市建设用地形态,并在不同区域表现出非均衡的空间差异。基于中国1981—2015年城市建设用地面积和人口数据,综合运用滑动T检验、K密度估计（KDE）和基尼系数等方法,识别中国城市建设用地转型的关键节点,并揭示其时空特征。结果表明：① 中国城市建设用地形态经历了“面积低速扩张—人均用地收缩”（1981—1990年）、“面积中速扩张—人均用地低速上升”（1990—2000年）、“面积快速扩张—人均用地快速上升”（2000—2015年）3个转型阶段。② 1990—2000年和2000—2015年两个转型阶段,面积转型的空间格局演变缓慢,表现出以东部长三角、珠三角为核心的大聚集和中西部以省会城市为中心的小分散格局,而人均用地转型空间格局呈由东部聚集向全国蔓延的演变趋势。③ 1990—2015年,城市建设用地面积的空间非均衡性表现为先逐渐缩小后逐渐扩大的动态演变特征,人均用地的空间非均衡性表现为先逐渐缩小后趋于稳定的演变特征。④ 中国城市建设用地转型符合区域土地利用转型的理论模式,与社会经济发展阶段转变相对应,空间格局演变揭示了国家发展战略由东部优先向区域协调发展转变的现实情况。研究在内容上弥补了土地利用转型阶段定量识别的不足,可为新时代社会经济转型背景下城市建设用地管控工作提供理论和数据依据。

Stages and spatial patterns of urban built-up land transition in China

Since the reform and opening-up in 1978, the morphology of urban built-up land (UBL) has been changed significantly due to the rapid socio-economic development in China. Moreover, this change shows an unbalanced variation over space. Based on the UBL area and census data from 1981 to 2015, we use the moving T-test, kernel density estimation and Gini coefficient to identify the abrupt change points over UBL transition process and present its dynamic spatial pattern. This research exhibits four main results. First, there are three identified stages over the transition process, namely, low expansion rate of UBL-decrease of per capita UBL (1981-2000), moderate expansion rate of UBL-slow increasing rate of per capita UBL(1990-2000) and high expansion rate of UBL-high increase of per capita UBL (2000-2015). Second, the spatial pattern of UBL area transition proceeds slowly over the periods of 1990-2000 and 2000-2015. Cities with a high expansion rate of UBL tend to present a spatial pattern of an agglomeration over the Yangtze River Delta and the Pearl River Delta, and the rest of the regions that tend to show a spatial pattern of an dispersion are provincial capitals in the central and western regions. On the contrary, cities with a high increasing rate of per capita UBL tend to originate from the eastern region to the entire country. Third, the variance of the UBL tends to be smaller during 1990-2000 and then greater during 2000-2015 over space, while the variance of the per capita UBL tends to be smaller during 1990-2000 and then stable during 2000-2015 over space. Lastly, we find that the results correspond to the previous theory of regional land use transition, and the socio-economic transformation phenomenon demonstrates the three identified stages. Moreover, the transition of spatial pattern reveals the fact that the change of national development strategy is from the priority of eastern coastal areas to the regional coordination. This work fills in a gap of quantifying the stage of land use transition, and provide support references to UBL management in the socio-economic transformation in the new era.