Guangzhou in Raster
Raster Imagery | Data Visualization | GIS
Raster Analysis Project for Urban Design Media
Instrutor: Suzy Li
The Greater Bay Area in China is one of the most prosperous metropolitan areas and has a great combination of elements in raster analysis.
This study is aimed at exploring the built environment and extraction of urbanization through the scope of vegetation, water and built-up area, with a time frame of a five-years period, from 2017 to 2022.
This period of time also marked milestones in the development of the bay including bridges across the
estuary
of the Pearl River, as well as cities’ continued efforts in land reclamation within the estuary.
MNDWI
The Modified Normalized Difference Water Index (MNDWI) uses green and SWIR bands for the enhancement of open water features.
The calculation equation is MNDWI = (Green - SWIR) / (Green + SWIR), referring to the Band 3 and 6 in Landsat 8. The threshold is currently set to 0.007.
In the map reclamation is noticed and the HK-Macau Bridge is shifting from a dashed line to continuous(see bottom of map). Meanwhile,
a pier from the HK international airport is built.
Additionally, a little furthur back from the bay, area of water resorvoirs observed is also changing in a noticable speed.
NVDI
The Normalized Difference Vegetation Index (NDVI) is a standardized index allowing you to generate an image displaying greenness (relative biomass). Calculation equation of the NVDI is NDVI = ((NIR - Red)/(NIR + Red)), which corresponds to Band 5,4 in Landsat 8.
The result shown above demonstrates the distribution and Guangzhou’s urban fabric shaped by the Baiyun Mountain and Pearl River.
With Conghua and Zengcheng’s high vegetation coverage, The remaining part of the city is more densely populated with built-up areas. Also, the map is showing that vegetation is growing in this period of time within the city. Areas of sparse vegetation changed to dense ones in a significant area.
Growth of built-up areas in the outer district is also really clear in terms of its pattern.
Huangpu, Zengcheng, Baiyun and Huadu are bridging accross the forest to connectivity.