Analysis of the urban expansion of Marília, São Paulo: a look at the periurban riparian forest remnants

Abstract:

Due to its locaton, the city of Marília, S P, is located in an important region for water supply in the west of São Paulo, and its urban area advances over the springs, making it necessary to preserve the already degraded and fragmented riparian forests. Thus, the objective was to temporally analyze the landscape in regions of water interest, in order to assess the potential for conservaton of the forest fragments responsible for this resource. A temporal analysis was carried out in the years 1989, 1999, 2009, and 2019, using images from the Landsat 5, 7 and 8 satellites, with 30 m of spatal resoluton. In the ArcMap 10.3 program, land use was grouped into six classes: forest formation, forest plantaton, natural non-forest formation, agriculture, non-vegetated areas, and water. For the entre municipality, landscape metrics CA (land cover) and PLAND (proporton of land cover) were calculated for the six land use classes. An analysis of the forest cover was carried out from a 5 km bufer around the urban area, and five more metrics of area, edge, and shape were calculated. Patich Analyst software version 5.2.0.16 was used to calculate landscape metrics. The classes that most stood out in terms of area size were agriculture (93,962.07 ha; 80.27%), forest formation (15,682.97 ha; 13.40%), and non-vegetated areas (5,220.63 ha; 4.46 %). The largest proportonal increases were in forest planting (0.11 to 1.27 ha), water (0.02 to 0.05 ha), and non-vegetated areas (2.17 to 4.45 ha), while agriculture lost area (85.73 to 80.27 ha). There has been an increase in forested areas in the last 30 years from the appearance of small and morphologically fragile fragments; in additon, with the increase in urban area, conflicts with the nearest forest remnants increase.

Keywords:
forest cover; water conservaton; landscape metrics