Urban Growth Characterization by Integration of Remote Sensing, Spatial Metrics and Population Data: A Case Study of Hanoi, Vietnam

Abstract

Vietnam, since the ‘Doi Moi’ reform policy in 1986, has gone through several economic development phases, resulting in various transformations of the landscape. One of the most evident is urbanization, a loss of agricultural lands and open spaces. These rapid changes pose an enormous challenge for local populations as well as planning authorities. This three-essay dissertation seeks to develop an improved understanding of the spatiotemporal urban growth characteristics of Hanoi in order to strengthen the region’s urban planning and management system. In the first essay, a method of monitoring built-up area changes in Hanoi from Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) was developed with a Support Vector Machine classification algorithm (SVM). The study showed that the SVM classification was an effective method to monitor built-up area changes over time with high accuracy. Most of the built-up area changes in Hanoi occurred between 2001 and 2006 and between 2006 and 2010, which were closely linked to population growth and major land management policies enforced in the beginning of 2000. The second essay analyzed the spatiotemporal patterns and dynamics of the built-up land in Hanoi using landscape expansion indices, spatial metrics and a gradient approach. The study showed that the urban landscape from 10 to 25 km buffer zones was more fragmented and over time there were temporal switches between coalescence and diffusion phases corresponding to the high urban growth rate in these zones. The complicated urban growth dynamics were successfully characterized and captured through this essay providing important information for urban modeling and prediction. The third essay explored the utility of spatial metrics and population data to delimitate peri-urban zone for Hanoi. Successfully identifying and mapping peri-urban zone is crucial to better manage this landscape where there is an intensification of conflict and where the governance and management are often neglected by both rural and urban administrators. The study showed that about 30% communes was rural, 38% communes was peri-urban and 32% communes was urban. The peri-urban zone showed a greater level of landscape fragmentation and population growth than urban or rural zones. The essay provided an effective method to map the rural-urban transition and to identify urbanization models of Hanoi where limited census data are available.