Sent to you by Robin via Google Reader:
Agriculture and Food Availability
Cultivating the City: Mapping and Characterizing Urban Agriculture with Satellite Imagery – Lisbon, Portugal
By Sérgio Freire, T. Santos, and J. A. Tenedório,
posted on November 26th, 2009
in Agriculture, Articles, Biodiversity, Earth Observation, Sustainability
Excerpts:
The city of Lisbon, Portugal, has historically expanded towards areas occupied by farms, orchards, and olive groves, thus integrating some rural character. This process was complemented by the influx of immigrants from the rural countryside or from abroad who had farming habits. While until recently this land use activity was perceived as marginal and simply tolerated by public officials, there are now municipal plans to expand it, organize it, and integrate it in the city planning process.
Within the city, agriculture typically takes place in small farms or clusters of plots in residual or vacant public land, occupying valleys, hillsides, and roadsides. After peaking in 1987, it is estimated that currently this land use occupies close to 84 hectares. However, since this is mostly an informal activity with limited official supervision, there is a lack of available accurate and updated records or geospatial data for assessment and analysis.
Conclusions
The present work is an on-going exploratory attempt, part of a wider goal of defining an expeditious method to obtain updated geographic information for municipal use. Accuracy of mapping urban agriculture using semi-automated feature extraction approaches was generally low. Semi-automated extraction of urban agriculture is complicated by the fact that the class is very heterogeneous, comprised of a mosaic of small parcels having: i) the same crops in different stages, ii) different crops, and iii) fallow or recently farmed parcels. This mapping and analysis effort has revealed availability of vacant areas with bare ground or natural vegetation, which could be used to support the expansion of urban agriculture in Lisbon in accordance with current municipal goals. Future developments include the use of another QuickBird image acquired in March 2007 to detect changes in land use. Also, more advanced contextual approaches should be explored to increase the accuracy of semi-automated detection and extraction of urban agriculture.
Things you can do from here:
- Subscribe to City Farmer News using Google Reader
- Get started using Google Reader to easily keep up with all your favorite sites
No comments:
Post a Comment