Urban Sprawl and Loss of Agricultural Land in Peri-urban Areas of Lagos

Examinations of ‘peri-urban’ remain elusive and often neglected by urban planners. However, these transitional zones are constantly under pressure by increasing populations from inner cities and migrants from the surrounding rural areas. The result in most developing countries is uncontrolled or unplanned landscapes. Although urban growth is inevitable and land use changes are imminent as peri-urban expansions of cities, peri-urban areas are pivotal regarding the agricultural resources necessary to urban survival. Understanding the development patterns, emerging urban forms, and their influences on peri-urban areas require an understanding of development decisions. Such knowledge will help decision makers and urban managers develop appropriate policies to address growth in ‘edge’ cities. This study focuses on the organic growth of Ikorodu, a peri-urban municipality on the outskirts of Lagos that emerged from a sleepy farming community with a population less than 100,000 in 1975 to a vibrant city exceeding one million residents in 2015. The study employs a multi-temporal remote sensing and GIS analysis to detect the urban pattern and emergent form over a 40-year period from 1975 to 2015. An empirical analysis was performed using survey data on 300 homeowners in 61 communities to identify the influences of rapid growth and the responses of planners to the city’s growth

对城市边缘区（peri-urban）的研究仍相对匮乏，且常被城市规划者所忽视。然而，这类过渡性区域始终承受着来自内城人口外迁以及周边乡村移民的增长压力。在多数发展中国家，这一状况最终导致景观开发失控、缺乏规划。尽管城市扩张势在必行，伴随城市边缘区扩张而来的土地利用变化亦在所难免，但城市边缘区对于保障城市存续所需的农业资源而言，其地位举足轻重。要洞悉城市边缘区的发展格局、新兴城市形态及其影响，必先理解其背后的发展决策逻辑。此类研究成果将助力决策者与城市管理者制定适配政策，以应对‘边缘城市’的扩张问题。本研究聚焦伊科罗杜（Ikorodu）的有机扩张历程：作为拉各斯（Lagos）市郊的城市边缘自治市，它从1975年不足10万人口的静谧农耕社区，发展为2015年人口超百万的活力都市。研究采用多时相遥感与地理信息系统（Geographic Information System, GIS）分析方法，对1975至2015年这40年间的城市格局与新兴形态进行监测与识别。此外，研究针对61个社区的300名房主开展问卷调查，通过实证分析厘清快速扩张带来的各类影响，以及规划者对该城市发展的应对举措。