- Size, Shape and Dispersion: Urban Form Evolution in Saigon River Basin and its Impact on hydrologic Performance from 1990 to 2000   click here to open paper content1253 kb
by    Nguyen, Dzung | nguyen.do@gmail.com   click here to send an email to the auther(s) of this paper
Short Outline
This paper provides an empirical study of urban form evolution in term of
size, shape, and dispersion within 2540 square kilometers of Saigon River
Basin and its hydrologic consequences during a 20-year period of rapid
urbanization.
Abstract
Urban form evolution causes hydrologic effects. Therefore, an understanding
of this critical relationship can provide planning and design solution to
make communities more sensitive and resilient to flooding. While several
studies have raised concerns on the impact of rapid and uncontrolled
urbanization in Ho Chi Minh City on the rise of Saigon River's water level,
none has tried to quantify the urbanization process at basin-scale and
associate this spatial phenomenon with water upheaval. In addition, the
search for a hydrologic-optimal urban form is critical for Ho Chi Minh City
region given the low infiltration rate of soil and rapid urbanization so
that minimizing impervious surface is a less relevant solution. Response to
this research gap and base on landscape ecology approach, this paper
provides an empirical study of urban form evolution in term of size
[urbanized area and number of urban patches], shape [compactness and
fractal] and dispersion [aggregation] within 2540 sqkm of Saigon River
Basin during a 20-year period of rapid urbanization. During this period,
impervious surface increased by 4 and 8 times in the whole basin and in the
flood-prone areas respectively while the population increased by two folds
only. Urban development in the Basin also became less compact, more fractal
but more aggregated. Using seven hydrologic-relevant landscape metrics and
a hydrologic index demonstrating run-off coefficient, the author presents
potential relationship between those form variables and the hydrologic
performance of the Basin. The result of this paper highlights that a more
compact and concentrated urban form for Saigon River Basin may result in
lower flood risk for Ho Chi Minh city. Further data collection and research
on watershed boundary, run-off estimation and hydrologic-relevant urban
metrics appears to be necessary to arrive with a statistically significant
conclusion.
Keywords
Case Study presented on the ISOCARP Congress 2013: Frontiers of Planning - Evolving and declining models of city planning practice
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