摘要
Urban growth is a key indicator of economic development.At the same time,haphazard urban growth creates serious socioeconomic,environmental and urban land management problems.In this context,understanding the process of urban landscape change is important for guiding the sustainable growth of urban areas.This study analyzes the urban land changes during 1990–2018 in two metropolitan cities of Gandaki basin:Pokhara and Bharatpur.Landsat satellite images were analyzed using supervised classification methods.The results revealed that the built-up area has increased significantly by 300%in Pokhara and by nearly 500%in the Bharatpur during the past 28 years.Population growth,migration from surrounding areas due to urban facilities and the easy lifestyle in cities were found to be major determinants of urban growth within the study area.In addition,the changing urban definition and expansion of municipal boundaries are key factors for rapid urban growth.Both cities are likely to grow in the future as they are both located in areas that encompass the high levels of commercial activity and modern service facilities.The haphazard urban growth should be minimized through planning and policies for sustainable urban development.
城市扩张是反映经济增长的重要指标,但随意的城市扩张也带来了严重的社会经济问题、环境问题以及城市土地管理问题。在这个背景下,理解城市扩张的过程对于指导城市的可持续增长具有重要意义。本研究采用基于遥感影像的监督分类方法,分析了甘达基流域内的两个大城市—博卡拉和巴拉普尔1990–2018年的城市用地变化。结果表明:在过去的28年,博卡拉和巴拉普尔的城市面积分别显著扩张了300%和近500%。人口增长、城市基础设施和便利的生活方式引起周边地区向城市的人口迁移,是造成本研究区城市扩张的主要原因。除此之外,不断变化的城市定义和城市边界的扩张是造成城市快速扩张的关键因素。由于上述两个城市拥有高水平的商业活动以及现代化的设施,未来城市规模可能继续扩大。应当通过城市规划和政策减少随意的城市扩张,从而实现城市的可持续发展。
基金
The National Natural Science Foundation of China(41761144081)
The Second Tibetan Plateau Scientific Expedition and Research(2019QZKK2203)
The International Partnership Program of Chinese Academy of Sciences(131C11KYSB20160061)
The Chinese Academy of Sciences-The World Academy of Sciences(CAS-TWAS)President’s Fellowship Program for Ph D Study