Abstract:

As the world's most populous country and the fifth-largest economy, India is undergoing rapid urbanization while facing significant challenges in urban expansion. Current studies on urban expansion are primarily focused on developed countries, with relatively less attention on developing nations. Using physical urban areas as urban space extracted from impervious surface data from 2000 to 2020, we characterize the spatio-temporal patterns of India's urban expansion and analyze the influencing factors from the perspectives of city size and regional differences. The results show: ①The intensity of India's urban expansion exhibits a phased trend, first increasing and then decreasing, with large cities being the main contributors. Since 2010, the overall expansion intensity of small and medium-sized cities has surpassed that of large cities, indicating a gradual shift toward balanced urban development. The spatial pattern of urban expansion has shifted from "higher in the south and lower in the north" to "lower in the south and higher in the north." Cities with rapid expansion show a distinct coastal and transportation-oriented pattern, shifting from coastal areas to inland transportation corridors. ②In large cities, compact expansion is more prevalent, concentrated in the southern and western regions of India, while small and medium-sized cities exhibit sprawling expansion, predominantly in the central, northern, and eastern regions. ③Elevation is the primary influencing factor for India's urban expansion, especially for medium-sized cities, followed by large cities. Regionally, the impact is most significant in the southern region, followed by the central region. In contrast, population density has only a localized impact on the central and eastern regions.

Key words: India, urban expansion, landscape expansion index, Geodetector

摘要：

作为全球人口最多的国家及第五大经济体，印度正在经历快速城市化进程，并面临显著的城市扩张带来的挑战。当前学术研究多聚焦于发达国家，而对发展中国家的关注相对较少。本研究利用2000—2020年的不透水面数据，界定城市实体范围，从规模和地区差异两方面探讨印度城市扩张的时空特征及其驱动因素。研究表明：①印度城市扩张强度经历了“初期增长，后期放缓”的演变过程，其间大城市扮演了关键角色；然而自2010年起，中小城市的扩张速度超越了大城市，标志着城市发展趋向均衡化。城市扩张的空间布局亦由南部高于北部逐渐转变为相反的格局，扩张热点从沿海地带转向内陆地区。②大城市倾向于紧凑型扩张，主要集中在印度南部和西部；相比之下，中小城市更多表现为蔓延式扩展，尤其在中部、北部和东部更为明显。③地形高度是影响城市扩张的重要因子，特别是对中等规模城市的影响尤为突出，其次为大城市。具体到区域差异，南部地区的高程效应最为强烈，其次是中部地区；人口密度仅对中部和东部的部分区域的城市扩展产生了局部影响。

关键词: 印度, 城市扩张, 景观扩张指数, 地理探测器