Análise espaço-temporal do uso e da ocupação associada à impermeabilização do solo na microbacia do Rio Granjeiro, CE.

Abstract

The watershed of the Granjeiro river covers almost the entire municipal seat of Crato. Their occupational characteristics combined with reliefs of the surroundings west of Chapada do Araripe and rainfall regimes higher than the semiarid, promote the generation of floods. This work tried to relate the use and land occupation with the land impermeabilization leveis and analyze the spatial distribution and changes of these factors in 2006 and 2014, in that area. The criteria that defined the use and occupancy patterns involved the density of construction and uncoated areas (urban) and type of vegetation and exposure of soil (rural or unoccupied land). Thus, were defined impermeabilization leveis for each class. The main change was identified in urbanization, which generated growth of more impermeable portions who have advanced south of the area. There was growth of 4% and 0.8% of the urban sectors of high and médium density and low-density areas, respectively. The use class corresponding to high infiltration retreated 4.3%, while the levei of maximum infiltration remained virtually unchanged. It was concluded from the perspective of the low to moderate infiltration upstream, along roads, from the urban center.