Hobart
Hobart
1972 - 1991
Hobart is the second smallest of the capital cities having a 1991 population
of 182,000. However, it must be close to number one with the beauty of its
location. Because of its climate it was difficult to obtain cloud-free images
of Hobart or of much of Tasmania. We are able to look back on Hobart for
just 9 years; from February 17, 1991 back to January 15, 1982.
What change can we expect? The population of Tasmania has grown at an annual rate of less than 1%, which is the slowest rate of all states. The total population in 1991 was 456 000 compared with 427 000 in 1981, which is as far back as we are able to look with our satellite images. Of the state population, just 40% reside in the Hobart suburban area. Hobart is the lowest city-state rank of all Australian capital cities.
Three Landsat FCC images of Hobart: January 15 1982, February 17 1991 and the 1982-1991 Difference.
Use your browser to open each image in a new window to compare them.
The urban complex that is Hobart is concentrated on the western side of the Derwent River. The blue signature of the high density, high rise CBD is small but distinctive. The surrounding suburbs spread particularly along the western edge of the Derwent River and ultimately grade into agricultural landcover in the upper reaches of the Derwent and Coal River valleys. The signatures of these two landcover types are spectrally and spatially dissimilar; particularly so in the 1982 image. The grain of urban areas is fine and their pink signature indicates a high level of green vegetation (lawns, gardens and playing fields) mixed with housing and industrial buildings. The agricultural landcover is, on the other hand, coarse grained with large distinct paddock and property boundaries. The vegetation cover is largely dry and non-green.
Both the 1982 or 1991 images show that the remaining cover of native vegetation - the tall open eucalypt forest (eT3L, AUSLIG 1990) - is restricted largely to the steep uplands. Most of the bottom lands have been cleared for either agriculture or urban purposes.
Hobart is a low density city. The spatial pattern of its growth appears to be largely determined by topography and perhaps that ever-present human want to be near, or at least to be able to see, water. With a small absolute population size coupled with a relatively low growth rate, it is not surprising that the urban complex shows very little change between 1982 and 1991. The Difference FCC image contains many areas where vegetation cover has been lost, but these are almost entirely in the agricultural areas. Some urban expansion can be detected on the periphery of Glenorchy and Berriedale in the west and Resdon Vale and Lindisfarne on the east. A new bridge across the Derwent at Glenorchy can also be detected.
In summary
The landcover changes that can be detected as part of the urban expansion of Hobart are very small indeed, and quite insignificant compared with those occurring in the nearby agricultural areas.
