合肥市建设扩张与生态格局时空演变特征分析

近20年来合肥市城市建设迅速发展,对生态环境稳定性产生一定影响。以景观指数为基础解析1995—2016年合肥市景观格局,并在此基础上计算反映建设用地与耕地景观时空演变特征的景观梯度及其动态度,研究城市建设对生态环境的影响。结果表明,20年来合肥市城市化进程致使建设用地面积增加85.68%,超过18.41%耕地流失,景观破碎化程度增加,形状复杂化,城市扩张导致城市生态环境脆弱性增加。近20年间城区以旧城区为中心持续向四周扩展,2005年之前主要往西南方向扩展,对其生态环境产生负面影响;2005年之后南部、北部扩展幅度较大,南、北部郊区的快速建设影响着其生态系统的稳定性;2010年之后外围城镇扩展速度增加,致使城区外围生态环境稳定性下降。城市扩张致使生态环境的胁迫作用持续增加,在城市化进程中应采取适当的措施改善城市建设与生态平衡的关系,促进可持续发展的城市建设。

The spatial-temporal evolution of the construction land expansion and ecological pattern in Hefei city

Nearly 20 years, the rapid urbanization has impacted on the stability of the ecological environment in Hefei. Based on the landscape index, this paper analyzed the landscape pattern of Hefei city from 1995 to 2016. The landscape gradient and its dynamic degree were calculated to reflect the temporal and spatial evolution characteristics of the construction land and cultivated land. The impact of urban construction on ecological environment was also analyzed. The results showed that the urbanization of Hefei city in the past 20 years resulted in a 85.68% increase of the construction land and a loss of more than 18.41% of the cultivated land. The degree of landscape fragmentation was increased and the shape was complicated. The urban expansion led to the increase of urban ecological and environmental vulnerability. In the recent 20 years, the urban area continued to expand around the old city center, and mainly expanded to the southwest before 2005, which had a negative impact on its ecological environment. After 2005, the south and north expanded more rapidly than other areas and the rapid construction impacted the stability of its ecosystem in these areas. After 2010, the expansion of peripheral cities and towns increased, resulting in the decline of the stability of the urban periphery. As a result of urban expansion, the coercive effect of the ecological environment continued to increase. In the process of urbanization, appropriate measures should be taken to improve the relationship between urban construction and ecological balance, and promote the construction of sustainable urban development.