O adensamento urbano e as mudanças no estuario do Rio Cocó-FORTALEZA/CE, frente à demanda das ações antrópicas comparativas entre os anos de 1985, 1996 e 2007

Abstract

The urban densification, which sued in the surroundings of the estuary of the Rio Cocó, favored by the huge population growth occurred in Fortaleza/CE/Brazil, in recent decades, involved in various negative impacts on site. In order to assess urban developments that took place in the surroundings of the estuary of the Rio Cocó and their negative impacts, in the period between 1985, 1996 and 2007, was held a multitemporal image analysis from TM/Landsat-5 of 1985, 1996 and 2007 in GIS (geographic information System). The procedure consisted of visual interpretation of images in different compositions in RGB (4-5-3; 4-3-2; 4-7-3; 5-4-2) and product obtained from processing images through the bands 3 and 4 in arithmetic operations tool present in the SPRING, subsidized by field recognition activities and consultations with maps, aerial photographs and satellite images of high spatial resolution, which resulted in the elaboration of maps of land cover and use for imaging each year. For each map were defined usage 09 units and soil cover (Urban Area; River; Natural Vegetation; Hipersalina Plain; Lagoons and swampy; Dunes; Beach track; Intermittent Interdunares ponds; Sand banks), which have been quantified and compared. It was noted that over the 22 years analyzed the urban area was the only unit to produce growth. The expansion of the urban area was to the detriment of other units, from 34.18% (15.44 km²) in 1985 to 55.62% (25.13 km²) in 2007, that is, there was an increase of 21.44% (9.69 km²); of the total urban area plus, 60.37% (5.85 km²) occurred between 1985 and 1996, and 39.63% (3.84 km²) in the period between 1996 and 2007. This smaller percentage can be explained by the fact that in the period between 1996 and 2007 have been reduction of repeated spaces, an appreciation of land occupation in the area and greater supervision and monitoring of urban sprawl within the bounds of Cocó ecological park. The data collection in the field enabled the identification of various negative impacts promoted by urbanization in the study area, such as: filling of mangrove and wetland, deforestation, disposal and rubble in the riverbed, discharge of domestic sewage, silting, among others. To see the effects of urbanization on the estuary sediment collections 22 were held on his deathbed through a background search dredge (Van Veen) in 11 seasons. Analysis of sediment collected was visual and allowed the recognition, in the samples of 01, 02, 03, 04 and 09, construction waste, such as pieces of bricks, tiles and cement clods and garbage and other residues. The results point to the need for a systematic monitoring of urban expansion in the area; for identification and control of pollutant loads from residential and commercial; for the promotion of environmental education in the area; for the extension of effective police monitoring Cocó ecological park and its suitability to the national system of conservation Units as (SNUC) – Federal Law No. 9985 July 2000.