深圳市近20年城市景观格局演变及其驱动因素

基于深圳市1996—2015年土地利用数据,利用景观指数、景观转移矩阵和景观扩张指数等方法探究了深圳市近20年景观格局时空变化、主要景观类型转移和建筑用地扩张模式,最后使用Binary Logit模型考察了市级和区级建筑用地景观扩张的主要驱动因素。结果表明：① 1996—2015年,深圳市建筑用地景观优势性逐步增强,面积增加15.81%,以蔓延式（61.9%）和填充式（36.27%）扩张为主;② 1996—2006年为城市化快速扩张期,建筑用地扩张呈集中开发形态,景观多样性和均匀性增加,城市扩张中心略微向北部和东部移动,2006—2015为城市化低速过渡期,景观破碎化加剧,城市扩张重心向北部和西部偏移;③ 在市级尺度上,GDP密度和人口密度对建筑用地景观扩张有显著正影响,生态控制线、高程、坡度和至道路的距离有着显著负影响。每单位生态控制线范围、坡度的增加分别将使建筑用地景观扩张的机会比率将平均减少到原来0.8168倍、0.8841倍。各驱动因素表现出区域和尺度差异性,GDP对宝安区、南山区和坪山区,人口增长对宝安区、龙华区,以及交通可达性对大鹏新区、龙岗区驱动分别最为突出。研究结果可以为中国城市快速扩张过程中的景观格局变化提供科学实践。

The evolution of urban landscape pattern and its driving forces of Shenzhen from 1996 to 2015

Since China's reform and opening up, Shenzhen has experienced rapid urbanization and dramatic changes in landscape patterns. On the basis of the land use dataset of Shenzhen city from 1996 to 2015, this study utilized landscape metrics, transition matrix and, expansion index to detect the spatiotemporal changes of urban landscape pattern, which analyzed the trend of landscape transfer and urban expansion. Also the major driving forces for landscape pattern changes on municipal and district scales were identified through the Binary Logit regression model. The results showed that: (1) the dominance of construction land landscape in Shenzhen gradually increased during the study period, with the construction land increasing by 15.81%, which occupied a large area of woodland (157.59 km2). The edge-expansion and infilling are the two main growth types of newly developed urban land, accounting for 61.19% and 36.27% respectively. (2) The rapid urbanization occurred from 1996 to 2006, during which landscape diversity and uniformity increased. (3) There was a low-speed urbanization transition from 2006 to 2015, during which landscape fragmentation intensified. The boundaries of the built-up areas became complex. However, due to the influence of land policy and red line of ecological protection, the rate of urban expansion slowed down. The pattern of urban expansion was mainly west-oriented, with the center continuing to shift northwards. (4) On the municipal scale, the GDP density and population density had a significant positive impact on the evolution of landscape pattern, while the ecological control line, elevation, slope and the distance to the road had a significant negative impact. The driving factors had the difference in scale and region, with GDP in Baoan, Nanshan and Pingshan districts, population growth in Baoan and Longhua districts, and traffic accessibility in Dapeng and Longgang districts being the most prominent drivers, respectively. This study can provide scientific practice for landscape pattern change in the process of rapid urban expansion in China.